classification 2 - oxford university...

2CLASSIFICATIONThe Earth is teeming with life. Approximately 1.8 million known types of organism (living thing) on the Earth have been described and named. Scientists estimate there are 10–30 million other kinds of living things that haven’t even been discovered yet. Scientists use classification to organise this diversity of life forms (biodiversity) in a logical fashion. Classification is an example of a system that scientists have created, and continue to develop, to help us better understand the world.

2.1CLASSIFYING LIVING THINGS

Classifying is a tool that is not restricted to the study of science. You probably classify things every day without really being aware of it. Classification is the process of separating items

based on similarities and differences.

Students:

» Identify the purpose of classification » Classify living things based on structural similarities and differences

» Explain how features of some Australian plants and animals are adaptations for survival and reproduction

2.2USING KEYS AS TOOLS FOR CLASSIFICATION

Once items have been classified, we can work backwards using what we already know to identify unknown items or organisms.

Students:

» Use the Linnaean classification system to name organisms » Use keys to identify plants and animals

2.3CLASSIFICATION TODAY

All known living things have already been classified. Using this information, new species that are discovered can also be classified based on the key features they have in common with

known species. How life is classified can change as new scientific discoveries are made.

Students:

» Outline the features used to group plants, animals, fungi and bacteria » Identify groups of microorganisms

51

CHAPTER 2 SYLLABUS LINKS

Outcomes SC4-14LW relates the structure and function of living things to their classification, survival and reproductionSC4-15LW explains how new biological evidence changes people’s understanding of the world

Knowledge and understanding LW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).Students:a identify reasons for classifying living things

b classify a variety of living things based on similarities and differences in structural features

c use simple keys to identify a range of plants and animals

d identify some examples of groups of microorganisms

e outline the structural features used to group living things, including plants, animals, fungi and bacteria

f explain how the features of some Australian plants and animals are adaptations for survival and reproduction in their environment

• design and construct simple keys to identify a range of living things (additional)

• classify, using a hierarchical system, a range of selected plants and animals to species level (additional)

Working scientifically SC4-4WS Questioning and predictingSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-9WS Communicating

Learning across the curriculum • Critical and creative thinking• Information and communication technology

capability• Literacy• Personal and social capability

INTRODUCING CHAPTER 2 This chapter introduces the concept of classification of living things based on their structure and function. It highlights the problematic nature of scientific knowledge, the effect of new technologies and how classification has been refined. Accurate identification of species is important for all branches of biology, so the skills developed in using dichotomous keys are fundamental.

This chapter builds upon Stage 3 outcome ST3-10NE: a student describes how structural features and other adaptations of living things help them to survive in their environment. Learning about classification provides a basis for Stage 5 outcome SC5-14KU: a student analyses interactions between components and processes within biological systems, and outcome SC5-15KU: a student explains how scientific understanding has advanced through scientific discoveries, technological developments and needs of society.

CHAPTER 2 CLASSIFICATION 50

UNCORRECTED PAGE PROOFS

2CLASSIFICATIONThe Earth is teeming with life. Approximately 1.8 million known types of organism (living thing) on the Earth have been described and named. Scientists estimate there are 10–30 million other kinds of living things that haven’t even been discovered yet. Scientists use classification to organise this diversity of life forms (biodiversity) in a logical fashion. Classification is an example of a system that scientists have created, and continue to develop, to help us better understand the world.

2.1CLASSIFYING LIVING THINGS

Classifying is a tool that is not restricted to the study of science. You probably classify things every day without really being aware of it. Classification is the process of separating items

based on similarities and differences.

Students:

» Identify the purpose of classification » Classify living things based on structural similarities and differences

» Explain how features of some Australian plants and animals are adaptations for survival and reproduction

2.2USING KEYS AS TOOLS FOR CLASSIFICATION

Once items have been classified, we can work backwards using what we already know to identify unknown items or organisms.

Students:

» Use the Linnaean classification system to name organisms » Use keys to identify plants and animals

2.3CLASSIFICATION TODAY

All known living things have already been classified. Using this information, new species that are discovered can also be classified based on the key features they have in common with

known species. How life is classified can change as new scientific discoveries are made.

Students:

» Outline the features used to group plants, animals, fungi and bacteria » Identify groups of microorganisms

51

Teaching strategyThis is probably the first biology topic

studied by students at secondary school, so

it is important to engage students with a

variety of practical activities and numerous

opportunities to observe living and/or

preserved specimens. Group work is useful

because it gives students opportunities to

discuss and justify their opinions. From time

to time, after doing practical classification

or identification activities, revisit the

relationships between structure, function,

survival, reproduction and classification.

Starter activity: The purpose of classification Use coloured pictures of a variety of

commonly known and unusual living

things. Place them around the room and get

students to move around to record words

and ideas of their responses to each picture

(floor storming). Collate and discuss student

responses in a class discussion about the

amount of biodiversity that exists.

Conduct a ‘think–pair–share’ activity to

come up with as many living things as possible

and place the organisms into a mind map.

Students compare the diversity of organisms listed and

their mind maps when sharing. As a class, discuss how

and why students grouped the organisms in the branches

of the mind map.

Introduce the concept of criteria as we use it in

everyday life when we classify objects and then in

classification of living things. For example, we could

classify medications based on how they are taken and

their form—orally (tablet, capsule, liquid), by injection

into a muscle or under the skin, absorbed (rubbed

on or by suppository—kids will love that!), inhaled.

We could alternatively classify medications based on

or their function, for example, destroying bacteria,

reducing pain or inflammation. This can be used to

introduce the distinction and relationships between

structure and function. You could then get students to

construct T-charts to identify structures and functions

in living things, or to present them in a cause-and-effect

relationship. The T-charts are useful for the diagnostic

assessment of student knowledge of living things.

Discuss examples of classification in everyday life, for

example, the hierarchical arrangement used in a library.

Identify the criteria for classifying the materials in a

library. Get students to suggest ways that the materials in

a public library may have changed over the past 50 years

and how the classification scheme may have changed.

Differentiation

For less able students:• Thesestudentsneedmoreconcreteexperiences.

Common activities include classifying the contents

of their pencil cases, pieces of laboratory equipment

or even buttons or food. Use these activities to

discuss the criteria used and relate to structure

and function of the items.

For more able students:• Thesestudentsmayalreadyunderstandmanyof

the concepts and relationships. They could be

challenged to choose and research an extreme or

unusual organism (for example, giant squid, ice fish,

deep sea bacteria, insect-eating plant) and present

information to the class that describes the features

and explains the classification of the organism.

Get the students to think critically and creatively to

produce a diary entry for the day in the life of their

selected organism.

TEACHER OBOOK EXTRAS > Teaching Program: Classification > Editable sample teaching program to cover

all aspects of Oxford Insight Science 7: Classification. Mapped to the NSW BOS Syllabus descriptors.

RESOURCES

51OXFORD INSIGHT SCIENCE 7 TEACHER KIT


CLASSIFYING LIVING THINGSEvery year, scientists are discovering plants and animals that have never been seen before. What if you were to find a new organism at your school? How would you know that no one else had discovered it? Could you describe it so that people on the other side of the world understood what it looked like and how it behaved? How would you know if it was alive?

To devise a useful classification system, scientists had to find a way to communicate that would make misunderstandings less likely. They needed to agree on common words they could use to describe certain characteristics, common languages for scientific papers and common processes for finding, describing and communicating their work.

The Greek philosopher Aristotle (384–322 bc) is considered by many to be the grandfather of classification. He found that each small township near his home had its own list of favourite plants and animals, described and ordered for its own purposes. He decided that this information should be shared and he set about finding a logical way to collect it. He sent his students out to gather local samples and stories. More than 500 types of plant and animal were collected

Figure 2.1 Early scientists used illustrations to help them communicate.

Figure 2.2 The 25–30 mm juvenile Eastern Blue Groper (a) could easily have been originally classified as a different type of fish to the 1.2 m adult (b).

2.1THE PURPOSE OF CLASSIFICATION

Classification is the process of organising objects or living things based on their similarities or differences in characteristics. Classification allows us to better understand the living world by helping us to:

• identify living things

• understand the history of living things on Earth

• show what is similar and different among living things

• communicate precisely, accurately and more easily.

The features, or criteria, we use to group living things are very important to

the usefulness of a classification system. Biologists study the structures and functions of organisms. They also investigate how organisms reproduce. These features are used in classification.

For example, botanists, scientists who study plants, use the structure of flowers to group them—this feature is important to the reproduction and distribution of many land plants. Zoologists, scientists who study animals, describe a group of mammals that give birth to live young in a relatively developed state as placental mammals. Humans are one example of a placental mammal.

a b

ACTIVITY 2.1.1: WHO AM I?

Choose a partner to work with. Describe an animal to your partner—make sure you don’t use the animal’s name. Your partner should try to draw the animal you describe. How accurate are they? Now your partner draws an animal while you try to guess what it is. How quickly did they guess your animal?

• How effective are word descriptions and drawings for communicating specific information about new species?

• What are the problems you can identify?• How might some of these problems have been overcome in more recent times?

Early classificationEarly scientists didn’t have the technologies to make or send exact images of their discoveries. Most of their communication was written as papers or letters, sent around the world to other scientists. They had to make illustrations and written descriptions of the plants and animals that they saw, and not all of them were great artists. Often, without knowing it, two scientists described the same organism that was at different stages of its life. Imagine finding a tadpole and a frog for the first time—how would you know they were the same animal?

and arranged in order of importance, according to where they lived and their shapes. Aristotle ordered them from what he thought was least important (rocks) to the most important (wild animals, men, kings, fallen angels, angels and God). He divided animals into those with blood (cats and dogs) and those that he thought had no blood (insects, worms and shelled animals).

For many years, other scientists used Aristotle’s classification system. Nearly 2000 years later, early explorers travelling to new lands found more new and different species—too many to fit into Aristotle’s 500 classification groups. They also questioned some of the groupings—were rocks alive and should angels and God be included in this system? Over the next hundred years a number of scientists developed new ways of describing and grouping living things.

Table 2.1 Scientists’ contributions to the classification system throughout history.

Scientist Improvement to classification

Andrea Cesalpino (1519–1603)

Classified plants into groups according to their trunks and fruits.

John Ray (1627–1705) Suggested that each scientist needed to observe an organism over the whole of its lifespan.

Augustus Quirinus Rivinus (1652–1723) and Joseph Pitton de Tournefort (1656–1708)

Suggested using a hierarchy of names. This meant starting with large general groups (like plants and animals) and then making each group smaller and smaller depending on its characteristics. Each organism had a long Latin name that described the characteristics of each level of the hierarchy. For example, a human would be described as an animal that breathes air, lives on land, has two legs and two arms, can give birth (if female) to live young that drink milk from their mother, has body hair, stands upright, uses tools and can speak.

Carolus Linnaeus (1707–1778)

Changed the descriptions to single words and reduced the number of classification groups to seven. His system is still used today. It is occasionally modified as new organisms are discovered and as we learn more about the organisms we already know.

52 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4 2.1 ClaSSIFyIng lIvIng ThIngS 53

CHAPTER 2 CLASSIFICATION 52 2.1 CLASSIFYING LIVING THINGS

being defined in the circle. This organiser

could be used extensively later in the chapter

to summarise some of the main groups of

living things. Initially it could be used to help

define and explain the term ‘classification’.

Common misconceptions Many people still refer to the koala as a ‘koala

bear’. This misconception is largely being

corrected in primary schools so most students

may understand that a koala is a marsupial

and does not belong with carnivorous bears. It

is an example of how scientific precision and

the proper use of scientific names is useful in

avoiding misconceptions.

Extension activities Students work in groups to develop a PMI

table about classification. Students should

be able to understand from the historical

examples how classification is a changing,

flexible process. They might like to explore the

advantages and disadvantages of this.

Alternatively, students could develop their

own classification lists based on the early

notion of classifying animals: whether they

UNIT 2.1 SYLLABUS LINKS

Outcomes SC4-15LW explains how new biological evidence changes people’s understanding of the world

Knowledge and understanding LW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).

Students:a identify reasons for classifying living things

Working scientifically

Activity 2.1.1: Who am I? SC4-7WS Processing and analysing data and informationSC4-8WS Problem solvingSC4-9WS Communicating

Learning across the curriculum • Literacy

INTRODUCING UNIT 2.1‘The purpose of classification’ and ‘Early

classification’ clearly address the syllabus content about reasons for classifying. This section contains excellent examples of the problematic nature of science understanding and the role of technology in the development and refinement of ideas.

Activity: The purpose of classification Bring in a range of plants or plant products, including

a range of edible plants. Discuss how early classification

was based on use. What would happen to the

classification if a plant was used as food, for fibre and

for construction? We classify plants we eat as fruit and

vegetables. Get the students to come up with their own

classification of the plants and plant products. One of

the issues that should arise is that classifying a tomato

as a vegetable and an orange as a fruit ignores the

structure of the plant. The terms ‘fruit’ and ‘vegetable’

have a different everyday meaning; botanists have a very

different definition of fruit.

Students could write the reasons that we classify

on sticky notes. With the teachers help they can group

the notes around the room. Examples of groupings are

communication, identification, and to see relationships.

A useful strategy for teaching new terms is to produce

a graphic organiser based on a table. The top left box is

‘definition’, top right is ’characteristics’, bottom left is

‘examples’ and bottom right is ‘non-examples’. Draw a

circle at the intersection of the boxes and place the term


CLASSIFYING LIVING THINGSEvery year, scientists are discovering plants and animals that have never been seen before. What if you were to find a new organism at your school? How would you know that no one else had discovered it? Could you describe it so that people on the other side of the world understood what it looked like and how it behaved? How would you know if it was alive?

To devise a useful classification system, scientists had to find a way to communicate that would make misunderstandings less likely. They needed to agree on common words they could use to describe certain characteristics, common languages for scientific papers and common processes for finding, describing and communicating their work.

The Greek philosopher Aristotle (384–322 bc) is considered by many to be the grandfather of classification. He found that each small township near his home had its own list of favourite plants and animals, described and ordered for its own purposes. He decided that this information should be shared and he set about finding a logical way to collect it. He sent his students out to gather local samples and stories. More than 500 types of plant and animal were collected

Figure 2.1 Early scientists used illustrations to help them communicate.

Figure 2.2 The 25–30 mm juvenile Eastern Blue Groper (a) could easily have been originally classified as a different type of fish to the 1.2 m adult (b).

2.1THE PURPOSE OF CLASSIFICATION

Classification is the process of organising objects or living things based on their similarities or differences in characteristics. Classification allows us to better understand the living world by helping us to:

• identify living things

• understand the history of living things on Earth

• show what is similar and different among living things

• communicate precisely, accurately and more easily.

The features, or criteria, we use to group living things are very important to

the usefulness of a classification system. Biologists study the structures and functions of organisms. They also investigate how organisms reproduce. These features are used in classification.

For example, botanists, scientists who study plants, use the structure of flowers to group them—this feature is important to the reproduction and distribution of many land plants. Zoologists, scientists who study animals, describe a group of mammals that give birth to live young in a relatively developed state as placental mammals. Humans are one example of a placental mammal.

a b

ACTIVITY 2.1.1: WHO AM I?

Choose a partner to work with. Describe an animal to your partner—make sure you don’t use the animal’s name. Your partner should try to draw the animal you describe. How accurate are they? Now your partner draws an animal while you try to guess what it is. How quickly did they guess your animal?

• How effective are word descriptions and drawings for communicating specific information about new species?

• What are the problems you can identify?• How might some of these problems have been overcome in more recent times?

Early classificationEarly scientists didn’t have the technologies to make or send exact images of their discoveries. Most of their communication was written as papers or letters, sent around the world to other scientists. They had to make illustrations and written descriptions of the plants and animals that they saw, and not all of them were great artists. Often, without knowing it, two scientists described the same organism that was at different stages of its life. Imagine finding a tadpole and a frog for the first time—how would you know they were the same animal?

and arranged in order of importance, according to where they lived and their shapes. Aristotle ordered them from what he thought was least important (rocks) to the most important (wild animals, men, kings, fallen angels, angels and God). He divided animals into those with blood (cats and dogs) and those that he thought had no blood (insects, worms and shelled animals).

For many years, other scientists used Aristotle’s classification system. Nearly 2000 years later, early explorers travelling to new lands found more new and different species—too many to fit into Aristotle’s 500 classification groups. They also questioned some of the groupings—were rocks alive and should angels and God be included in this system? Over the next hundred years a number of scientists developed new ways of describing and grouping living things.

Table 2.1 Scientists’ contributions to the classification system throughout history.

Scientist Improvement to classification

Andrea Cesalpino (1519–1603)

Classified plants into groups according to their trunks and fruits.

John Ray (1627–1705) Suggested that each scientist needed to observe an organism over the whole of its lifespan.

Augustus Quirinus Rivinus (1652–1723) and Joseph Pitton de Tournefort (1656–1708)

Suggested using a hierarchy of names. This meant starting with large general groups (like plants and animals) and then making each group smaller and smaller depending on its characteristics. Each organism had a long Latin name that described the characteristics of each level of the hierarchy. For example, a human would be described as an animal that breathes air, lives on land, has two legs and two arms, can give birth (if female) to live young that drink milk from their mother, has body hair, stands upright, uses tools and can speak.

Carolus Linnaeus (1707–1778)

Changed the descriptions to single words and reduced the number of classification groups to seven. His system is still used today. It is occasionally modified as new organisms are discovered and as we learn more about the organisms we already know.



had blood or no blood. Students could think

of other criteria to classify living things. What

would happen if colour was the criterion used

for classification?

ANSWERS

ACTIVITY 2.1.1 Who am I? This activity demonstrates to students that through classification and the subsequent naming of animals we can instantly understand about an animal by conveying its name (i.e., scientific classification). If this does not exist, and every time we refer to an animal we have to describe a range of characteristics to communicate, then communication would be laborious and less effective.

> Weblink: Images of organismsThis website provides some images of organisms for students to study.

> Weblink: Think–pair–shareThis website gives details on how to conduct a ‘think–pair–share activity’> Weblink: How to use T charts

This website gives instructions on how to use T charts

RESOURCES


Figure 2.3 (a) Dental plaque contains bacteria. (b) What van Leeuwenhoek saw that gave him nightmares: bacteria like these were living in his own mouth (as they do in yours).

ACTIVITY 2.1.2: CLASSIFYING CLOTHES

Brainstorm a list of clothes that you have in your wardrobe. You only need to include one type of each so if you have five pairs of jeans just include ‘jeans’ as a type of clothing. Work in a group to classify the items based on their structures (material type, e.g. cotton, silk) and functions (to be worn on the upper part of the body, or the lower part of the body).

• What criteria did you use to place the items into groups?• Discuss how classification of clothes helps us to understand and communicate

about these types of objects.

Discovery of microworldsAfter the invention of the first crude microscopes in the 17th and 18th centuries, science took off in a new direction. Fascinating tiny creatures that nobody had ever seen before were being discovered all over the world. New classification systems were needed to make room for these organisms.

The first person to discover microscopic organisms was a Dutch scientist named Antonie van Leeuwenhoek (pronounced Lay-ven-hock) in the late 17th century. His first discoveries gave him quite a shock.

One day, van Leeuwenhoek noticed that his local water supply looked greenish and had begun to smell. He decided to look at a drop of the water with the microscope he

had just made. At first, he saw plant-like things containing long strands and

tiny green globules floating gently a

b

ACTIVITY 2.1.3: DIFFERENT CELLS

Use a light microscope set up by your teacher and prepared slides to look at a range of microorganisms such as yeast and algae. Observe the differences between cells. Draw at least two different types of cells as accurately as you can, including any key structural differences. Label your diagrams. If you do not know the name of a particular structure, make one up for this exercise. Your teacher will give you its correct name later.

Write a brief description of each type of cell that you drew next to the appropriate diagram.

Compare your diagram and your written description with others in your class. Can you tell if you have drawn and described the same type of cells?

• What are some of the difficulties of using drawings and written descriptions to classify living things?

• Did you and your classmates use the same names for the cell structures? How does this affect communication between scientists?

• How could modern technology improve communication about classification?

about. But mixed in among the globules were a host of tiny creatures (that he named ‘animalcules’) darting to and fro. No doubt he began to wonder what he had been drinking every day!

‘If these tiny creatures lived in water’, he thought, ‘I wonder if they live inside us?’ He then examined the plaque between his own teeth. He also collected plaque from some other people (including one man who had never cleaned his teeth in his life). If the water-borne organisms looked frightening, imagine how van Leeuwenhoek felt when he saw enormous numbers of tiny organisms swimming around in the material taken from his own mouth. Van Leeuwenhoek is thought to be the first person ever to see bacteria.

The development of the microscope also led to another important discovery—all living things are made up of cells. You will learn more about cells in chapter 3.

Discovering new living thingsYou might think that scientists have identified all living things by now. They’ve been actively finding and classifying new organisms for hundreds of years. In fact, we will possibly never stop finding new types of organism, which is wonderful when you consider the benefits of such biodiversity.

Small groups of scientists are trying to find undiscovered plants in Brazilian rainforests before they are destroyed by logging and farming. Often large

pharmaceutical companies from other countries support them. Why would companies on the other side of the world be interested in saving plants and animals in the rainforest? One reason is that we may one day need these undiscovered organisms. Many of the medications we currently use come from organisms. The antibiotic penicillin was discovered from a type of mould; aspirin comes from a substance in the bark of willow trees. The next painkiller could come from a small fungus in a rainforest, or from an insect that relies on the fungus for food.

Figure 2.4 The rainforests of Brazil contain many undiscovered plant species.

Remember1 Define the term ‘classification’.2 Aristotle was one of the first scientists to try to gather information from wide regions.

Describe what method he used to organise all the observations from his observers.3 Describe what an ‘animalcule’ is, based on van Leeuwenhoek’s observations.

apply4 The earliest scientists did not have pens or paper. Hypothesise how they might

have passed on the information they received. How accurate would it have been?5 Investigate why Carolus Linnaeus simplified the classification system used by

previous scientists.6 Outline two reasons why scientists still classify organisms today.7 Describe places where you see everyday examples of classification.8 Explain why classification is useful.

QUESTIONS 2.1.1: THE PURPOSE OF CLASSIFICATION



historical understandings. People believed

in the spontaneous generation of life. When

they saw rotting meat become covered in

maggots they presumed the maggots arose

out of the dead flesh. Their understanding of

the life cycles of organisms and the variety of

ways that living things reproduced had not

developed. It was not until the 1740s that

van Helmont discounted that plants took

their nutritional needs solely from the soil

they grew in. Students could use the student

book text to list ideas that have since been

abandoned or replaced.

For more-able students: • Classificationisaframeworkthatisa

reference point in the event of a discovery

of a new species. This is more challenging

if we want to classify and understand extinct

animals based on modern classification.

Students each research one of the extinct

Australian megafauna and describe its

characteristics and how it is classified.

Activity: Summarising theoriesIt is worth setting the development of

classification against the background of

Activity: Discovering new living things The information in the student book entitled

‘Discovering new living things’ can be used for

comprehension/literacy activities. Students can extract

the main ideas and then suggest other reasons why it is

important to still try to find new species. This part of the

text links to the information about black smokers in the

Making Connections section at the end of the chapter.

Differentiation

For less-able students: • Identifythreeplantsandthreeanimalsthatare

indigenous to the region around your school.

Students can plan to establish a mini-botanical/

zoological garden to house these living things

and display them so the public understand their

classification. Students research how they will

display/house the living things and what they would

need to ensure they had all of their requirements.

SYLLABUS LINKS





Activity 2.1.2: Classifying clothes SC4-7WS Processing and analysing data and informationSC4-8WS Problem solvingSC4-9WS Communicating

Activity 2.1.3: Different cells SC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-9WS Communicating


capability• Literacy• Personal and social capability


Figure 2.3 (a) Dental plaque contains bacteria. (b) What van Leeuwenhoek saw that gave him nightmares: bacteria like these were living in his own mouth (as they do in yours).

ACTIVITY 2.1.2: CLASSIFYING CLOTHES

Brainstorm a list of clothes that you have in your wardrobe. You only need to include one type of each so if you have five pairs of jeans just include ‘jeans’ as a type of clothing. Work in a group to classify the items based on their structures (material type, e.g. cotton, silk) and functions (to be worn on the upper part of the body, or the lower part of the body).

• What criteria did you use to place the items into groups?• Discuss how classification of clothes helps us to understand and communicate

about these types of objects.

Discovery of microworldsAfter the invention of the first crude microscopes in the 17th and 18th centuries, science took off in a new direction. Fascinating tiny creatures that nobody had ever seen before were being discovered all over the world. New classification systems were needed to make room for these organisms.

The first person to discover microscopic organisms was a Dutch scientist named Antonie van Leeuwenhoek (pronounced Lay-ven-hock) in the late 17th century. His first discoveries gave him quite a shock.

One day, van Leeuwenhoek noticed that his local water supply looked greenish and had begun to smell. He decided to look at a drop of the water with the microscope he

had just made. At first, he saw plant-like things containing long strands and

tiny green globules floating gently a

b

ACTIVITY 2.1.3: DIFFERENT CELLS

Use a light microscope set up by your teacher and prepared slides to look at a range of microorganisms such as yeast and algae. Observe the differences between cells. Draw at least two different types of cells as accurately as you can, including any key structural differences. Label your diagrams. If you do not know the name of a particular structure, make one up for this exercise. Your teacher will give you its correct name later.

Write a brief description of each type of cell that you drew next to the appropriate diagram.

Compare your diagram and your written description with others in your class. Can you tell if you have drawn and described the same type of cells?

• What are some of the difficulties of using drawings and written descriptions to classify living things?

• Did you and your classmates use the same names for the cell structures? How does this affect communication between scientists?

• How could modern technology improve communication about classification?

about. But mixed in among the globules were a host of tiny creatures (that he named ‘animalcules’) darting to and fro. No doubt he began to wonder what he had been drinking every day!

‘If these tiny creatures lived in water’, he thought, ‘I wonder if they live inside us?’ He then examined the plaque between his own teeth. He also collected plaque from some other people (including one man who had never cleaned his teeth in his life). If the water-borne organisms looked frightening, imagine how van Leeuwenhoek felt when he saw enormous numbers of tiny organisms swimming around in the material taken from his own mouth. Van Leeuwenhoek is thought to be the first person ever to see bacteria.

The development of the microscope also led to another important discovery—all living things are made up of cells. You will learn more about cells in chapter 3.

Discovering new living thingsYou might think that scientists have identified all living things by now. They’ve been actively finding and classifying new organisms for hundreds of years. In fact, we will possibly never stop finding new types of organism, which is wonderful when you consider the benefits of such biodiversity.

Small groups of scientists are trying to find undiscovered plants in Brazilian rainforests before they are destroyed by logging and farming. Often large

pharmaceutical companies from other countries support them. Why would companies on the other side of the world be interested in saving plants and animals in the rainforest? One reason is that we may one day need these undiscovered organisms. Many of the medications we currently use come from organisms. The antibiotic penicillin was discovered from a type of mould; aspirin comes from a substance in the bark of willow trees. The next painkiller could come from a small fungus in a rainforest, or from an insect that relies on the fungus for food.

Figure 2.4 The rainforests of Brazil contain many undiscovered plant species.

Remember1 Define the term ‘classification’.2 Aristotle was one of the first scientists to try to gather information from wide regions.

Describe what method he used to organise all the observations from his observers.3 Describe what an ‘animalcule’ is, based on van Leeuwenhoek’s observations.

apply4 The earliest scientists did not have pens or paper. Hypothesise how they might

have passed on the information they received. How accurate would it have been?5 Investigate why Carolus Linnaeus simplified the classification system used by

previous scientists.6 Outline two reasons why scientists still classify organisms today.7 Describe places where you see everyday examples of classification.8 Explain why classification is useful.

QUESTIONS 2.1.1: THE PURPOSE OF CLASSIFICATION



TEACHER OBOOK EXTRAS > Risk assessment: Activity 2.1.2 Classifying

clothes

STUDENT OBOOK EXTRAS > Weblink: Discovery of microworlds > Website outlining the work of Leeuwenhoek > Risk assessment: Activity 2.1.3 Different cells > Editable risk assessment of the activity written

by a qualified and experienced laboratory technician

> Weblink: Discovering new living things

RESOURCES

3 An ‘animalcule’ is a tiny (microscopic) organism so-named by Antonie van Leeuwenhoek to describe the microbes he saw in his water supply.

4 Early scientists would have passed on their information verbally and with some drawings. The accuracy would have been questionable because spoken details often change as information is passed along. An example of problems of interpretation has arisen from evidence from Indigenous rock art about the distribution of the platypus near Laura in Cape York. Some claim it is evidence that the platypus distribution has decreased; others debate the interpretation.

5 Many species were regularly referred to by a number of different names, some of which were very long and complicated. This made communication between scientists very difficult. So, Linnaeus simplified the classification system by using two names for every species.

6 Scientists still classify organisms today in order to organise life forms in a logical fashion. This helps us to better understand the world and communicate, and it is a basis for study of any new life forms that are discovered. The ultimate goal of classification is to show the evolutionary history of life on the Earth.

7 Student responses will vary but may include: library books based on genre and author, clothing stores where items are grouped according to design and size, hardware according to use.

8 Classification is useful because it enables us to group items and organisms together based on their similarities. Organisms in the same classification would look, behave and develop in similar ways and so can be dealt with in similar ways.

Extension activity: Classifying leaves Give students a wide range of leaves:

compound and simple, different shapes,

margins, sizes, colours, ways the leaf stalk is

attached to the leaf blade. Students classify

them and then list the criteria they used to

group them.

This activity should reinforce that

scientists need to be able to define structures

precisely when they classify organisms in

order to make communication clear.

ANSWERS

QUESTIONS 2.1.1 The purpose of classification 1 Classification is the process of grouping

items based on similarities and differences in characteristics.

2 Aristotle used an order of least important (rocks) to most important (wild animals, man), and then further divided into animals with blood (dogs, cats, etc.) and those he thought had no blood (insects, worms, etc.).


CLASSIFICATION OF LIVING THINGSOne of the first decisions most scientists have to make when classifying something for the first time is if it is alive. What does it mean to be alive? What is the difference between us and the chairs we sit on? Both plants and animals are considered to be alive. What do we have in common that makes us alive? Living things are more properly called organisms.

Characteristics of living thingsIt has taken many years of observation and discussion for scientists to develop eight characteristics that all organisms—plants, animals and even microorganisms like bacteria—have in common. To remember all eight characteristics, just remember the mnemonic (a memory trick to help you remember information) MR N GREWW.

Non-living things may have some of the characteristics of organisms, but will not have all eight, or will not be able to do some of them by themselves. For example, a steam train can move on its own and requires coal for its energy, but trains do not grow over time or make baby trains! So a train is a non-living thing.

M ORGANISMS CAN MOVE BY THEMSELVES

Cats chase mice, birds flap their wings as they fly and fish swish their tails as

they swim. Animal movements are easy to see. But do plants move? Look at the leaves on an indoor plant—they usually face the window (a source of light). Turn the plant around so that the leaves face into a darker part of

the room. In a few days, the leaves will again be facing the window. The

leaves have moved by themselves. The sunflowers in Figure 2.5 turn their heads to follow the sun as it moves across the sky each day and carnivorous plants such as Venus flytraps will move to trap insects.

R ORGANISMS CAN REPRODUCE

Organisms can make new individuals that grow up to look like them. Animals like the elephants in Figure 2.6 mate and produce offspring, plants produce seeds that grow into new plants, and bacteria divide to produce more bacteria. Reproduction is the process by which living things make new life.

N ORGANISMS NEED NUTRITION

Organisms need nutrients to survive. Animals obtain most of their nutrients by eating food and drinking. Plants absorb nutrients through their roots and fungi feed on decaying organisms. Plants are autotrophs, which means that they make their own food using the energy from sunlight in a process called photosynthesis. Animals and fungi are heterotrophs—they rely on other living things for food like the snake in Figure 2.7.

G ORGANISMS GROW AS THEY GET OLDER

All organisms grow during their lives. Mushrooms start off as tiny spores. Humans are born as babies, developing into children, teenagers and then adults. The tadpoles in Figure 2.8, will hatch from their eggs then metamorphose into adult frogs. In every case, living things, when fully grown, resemble those adults who produced them.

Figure 2.5

Figure 2.7

Figure 2.8

Figure 2.9

Figure 2.10

Figure 2.11

R ORGANISMS RESPOND TO STIMULI

When an animal realises it is being chased, like the antelope in Figure 2.9, it runs. It is responding to stimuli (the sight and sound of a charging predator) or to changes in its environment (the sudden brush of leaves or movement of shadows). The sunflowers shown in Figure 2.5 are responding to the changing stimulus of light and warmth. When you accidentally brush your finger against something hot, like an iron, you pull back—your body is responding to the stimulus of heat.

E ORGANISMS EXCHANGE GASES WITH THEIR ENVIRONMENTS

Plants and animals have organs and structures that allow them to exchange oxygen and other gases. Some animals, like humans, use their lungs to inhale and then exhale. Other animals, like fish and axolotls (Figure 2.10), have gills. Some animals, like worms, breathe through their skin. Bacteria are different to plants and animals: they do not have organs, but they still exchange gases. Some types of bacteria die in the presence of oxygen but use and produce other gases.

Figure 2.12

W ORGANISMS REQUIRE WATER

All organisms need water; it is required for many functions. For example, it transports substances in our bodies to where they are needed and it is involved in many important chemical reactions. In animals such as humans, it helps maintain body temperature. No wonder a large proportion of our body is water!

W ORGANISMS PRODUCE WASTES

We, like other animals, take in food, water and air to fuel our bodies. Chemical reactions occur in our bodies and wastes are produced as a result. We get rid of these by exhaling, sweating (Figure 2.12), urinating and defecating (emptying our bowels). Plants get rid of their wastes through their leaves.

If an organism could not get rid of its wastes, they would build up, become toxic and eventually cause the organism to die.

Figure 2.6



Starter activity

Suggest to the students that everything we eat comes

from living things. Students brainstorm a list of foods

and, for each, try to make a link back to the living thing.

The main exception that some students may think of is

salt, which is inorganic.

Teaching strategyLiteracy activities and case studies are ideally suited to

this content. Students could be given a list of statements

that are examples of ways living things meet the eight

requirements, and then classify them to one of the eight

characteristics. Statements could include hatch from eggs,

change from a caterpillar into a moth, hibernate when days

become short, and search for shrimps in the creek bed using

a highly sensitive bill.

Activity: Classification of living thingsThis content builds directly on Stage 2, where students

have to sort objects as either living or non-living. So

students already have a sense of what is living and non-

living. It is worth doing a ‘think–pair–share’ activity

to encourage students to come up with their own

characteristics. Students’ ideas could be linked to a

concept map that contains the eight characteristics from

the student book text.

Students list as many different ways as possible

that each of the eight characteristics can be achieved.

Reproduction is an unusual characteristic in that all

living things do not necessarily reproduce. Species such

as bees behave more like a colony than an individual.

It is the queen bee and only a few select males that

reproduce, yet bees are undoubtedly alive. Use a wide

range of illustrations of living things to

prompt discussion of the variety of ways that

living things meet their requirements.

Additional informationThe point that living things exchange gases

is particularly confusing when discussing

aquatic organisms. Gases are not very

soluble in water, so it is possible to set up

a demonstration that shows an aquatic

plant releasing bubbles of gas, which can be

collected and tested to show that it is oxygen.

Mostly, oxygen and carbon dioxide are in a

weak solution and they are not exchanged in

the gaseous form. Technically we should say

that living things expel and absorb gases or

gases in solution.

Common misconceptionsThe term ‘exchange gases’ can be quite

misleading: students may assume that one

gas is actually swapped for another. It has

some use in vertebrates when considering the

action of lungs or gills: oxygen is absorbed,

carbon dioxide is expelled and generally

the more oxygen that is required, the more

SYLLABUS LINKS

OutcomesSC4-14LW relates the structure and function of living things to their classification, survival and reproduction

Knowledge and understandingLW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).



Learning across the curriculum• Literacy


CLASSIFICATION OF LIVING THINGSOne of the first decisions most scientists have to make when classifying something for the first time is if it is alive. What does it mean to be alive? What is the difference between us and the chairs we sit on? Both plants and animals are considered to be alive. What do we have in common that makes us alive? Living things are more properly called organisms.

Characteristics of living thingsIt has taken many years of observation and discussion for scientists to develop eight characteristics that all organisms—plants, animals and even microorganisms like bacteria—have in common. To remember all eight characteristics, just remember the mnemonic (a memory trick to help you remember information) MR N GREWW.

Non-living things may have some of the characteristics of organisms, but will not have all eight, or will not be able to do some of them by themselves. For example, a steam train can move on its own and requires coal for its energy, but trains do not grow over time or make baby trains! So a train is a non-living thing.

M ORGANISMS CAN MOVE BY THEMSELVES

Cats chase mice, birds flap their wings as they fly and fish swish their tails as

they swim. Animal movements are easy to see. But do plants move? Look at the leaves on an indoor plant—they usually face the window (a source of light). Turn the plant around so that the leaves face into a darker part of

the room. In a few days, the leaves will again be facing the window. The

leaves have moved by themselves. The sunflowers in Figure 2.5 turn their heads to follow the sun as it moves across the sky each day and carnivorous plants such as Venus flytraps will move to trap insects.

R ORGANISMS CAN REPRODUCE

Organisms can make new individuals that grow up to look like them. Animals like the elephants in Figure 2.6 mate and produce offspring, plants produce seeds that grow into new plants, and bacteria divide to produce more bacteria. Reproduction is the process by which living things make new life.

N ORGANISMS NEED NUTRITION

Organisms need nutrients to survive. Animals obtain most of their nutrients by eating food and drinking. Plants absorb nutrients through their roots and fungi feed on decaying organisms. Plants are autotrophs, which means that they make their own food using the energy from sunlight in a process called photosynthesis. Animals and fungi are heterotrophs—they rely on other living things for food like the snake in Figure 2.7.

G ORGANISMS GROW AS THEY GET OLDER

All organisms grow during their lives. Mushrooms start off as tiny spores. Humans are born as babies, developing into children, teenagers and then adults. The tadpoles in Figure 2.8, will hatch from their eggs then metamorphose into adult frogs. In every case, living things, when fully grown, resemble those adults who produced them.

Figure 2.5

Figure 2.7

Figure 2.8

Figure 2.9

Figure 2.10

Figure 2.11

R ORGANISMS RESPOND TO STIMULI

When an animal realises it is being chased, like the antelope in Figure 2.9, it runs. It is responding to stimuli (the sight and sound of a charging predator) or to changes in its environment (the sudden brush of leaves or movement of shadows). The sunflowers shown in Figure 2.5 are responding to the changing stimulus of light and warmth. When you accidentally brush your finger against something hot, like an iron, you pull back—your body is responding to the stimulus of heat.

E ORGANISMS EXCHANGE GASES WITH THEIR ENVIRONMENTS

Plants and animals have organs and structures that allow them to exchange oxygen and other gases. Some animals, like humans, use their lungs to inhale and then exhale. Other animals, like fish and axolotls (Figure 2.10), have gills. Some animals, like worms, breathe through their skin. Bacteria are different to plants and animals: they do not have organs, but they still exchange gases. Some types of bacteria die in the presence of oxygen but use and produce other gases.

Figure 2.12

W ORGANISMS REQUIRE WATER

All organisms need water; it is required for many functions. For example, it transports substances in our bodies to where they are needed and it is involved in many important chemical reactions. In animals such as humans, it helps maintain body temperature. No wonder a large proportion of our body is water!

W ORGANISMS PRODUCE WASTES

We, like other animals, take in food, water and air to fuel our bodies. Chemical reactions occur in our bodies and wastes are produced as a result. We get rid of these by exhaling, sweating (Figure 2.12), urinating and defecating (emptying our bowels). Plants get rid of their wastes through their leaves.

If an organism could not get rid of its wastes, they would build up, become toxic and eventually cause the organism to die.

Figure 2.6



carbon dioxide will be expelled. In plants, the

‘exchange’ of gases varies. During the day,

plants may absorb carbon dioxide and release

oxygen, but at night they do the reverse.

In humans, haemoglobin carries the

oxygen in the blood. The carbon dioxide

is carried in three forms: most is carried

as bicarbonate ions, a small proportion

is dissolved in the plasma and 5–10% is

bound to haemoglobin. In a sense, a small

proportion of haemoglobin molecules will

release carbon dioxide and absorb oxygen in

the lungs in an exchange-like process, but

many more haemoglobin molecules are not

carrying anything and just absorb oxygen in

the lungs.

Extension activity: living or notStudents walk around a small section of the

school grounds and list the things they see

under the headings ‘living’ and ‘non-living’.

Alongside, they list the characteristics of the

living things they have observed.

TEACHER OBOOK EXTRASWeblink: Lesson plans some useful reading strategies on classifying living things.

WORKBOOK OBOOK EXTRASWorksheet 2.1: Living and non-living

> Editable version of workbook activity, which can be digitally assigned to students for homework

RESOURCES


ACTIVITY 2.1.4: THE FIRE

Is a bushfire alive or not?1 Work in a group of four, divided into pairs. One pair has to argue in favour of a fire

being alive. The other pair has to argue that it is not alive.2 Each pair has 5 minutes to come up with a list of characteristics that support

whether a fire is living or not.3 When the time is up, have a class discussion about whether a fire is alive or not,

and perhaps whether other characteristics for classifying ‘alive’ may be required.

Non-living or dead?Something classified as living needs nutrition and water, and is able to move by itself, reproduce, exchange gases, grow, respond to stimuli and produce wastes. If something doesn’t have these characteristics it would seem logical to assume that the thing is non-living.

What about something that is dead? Something dead, such as a dried flower or an Egyptian mummy, was once living; when it was alive it did have the characteristics of a living thing. Something that is non-

living, such as a computer or your watch, never had these characteristics.

All living things are made up of cells. Once that living thing dies, the cells remain, but they are no longer functioning. Dead things are usually distinguished from non-living things in that they are still made up of cells. The wood of a desk, for example, was once a living tree. If you were to examine the wood under a microscope, you would see that it is still made up of cells. A plastic chair contains no cells; it is made up of molecules of plastic. It is a non-living object. You will learn more about cells in chapter 3.

Bakers use yeast (a type of microorganism) to help their bread to rise. The yeast cells use the sugar in the dough as nutrients and produce carbon dioxide, which causes the dough to rise. Yeast can also be bought as a dry powder.

Design an experiment to determine whether or not dried yeast is still alive.

• What key features of living things can you test for?

• What variables should you keep the same (controlled variables) to ensure you have designed a fair test?

• Discuss your method and results.• Is dried yeast a living thing? How do

you know?• When you have finished, your teacher

may give you a few research questions to complete.

ACTIVITY 2.1.5: DEAD OR ALIVE?

DEEPER UNDERSTANDING Encyclopedia of Life

Edward O. Wilson, one of the world’s most well-known biologists, has taken on the seemingly impossible task of compiling a list of the nearly 2 million known species on our planet. He is developing an online database of all life on the Earth. The Encyclopedia of Life (EOL) aims to make all knowledge of the world’s known species freely available to all. The initiative was

launched on 9 May 2007. As new species are discovered they will be added to the database. Every species will have its own page, with links to all known information about that species.

The EOL will be a tool not only for scientists but also for students, teachers and the public to gain a better understanding of all life on the Earth.

Remember1 The system scientists use to group things divides them first into two groups.

Identify these two groups.2 Apart from the eight characteristics of life, identify one other thing that all

living things have in common.3 Explain how to distinguish a non-living object from something that is dead,

and how to distinguish a living thing from a dead thing.

apply4 Consider Table 2.2.

Table 2.2 living or non-living?

Eucalypt tree

Water Paper Robot leather belt

Wombat Roast chicken

Computer virus

Moves by itself

Reproduces itself

Requires nutrition

Grows as it gets older

Responds to changes in its environment

Exchanges gas (e.g. oxygen)

Produces wastes

Requires water

living or non-living?

a With a partner or by yourself, decide if each of the items meets the requirement to be classified as a living thing.

b Decide if each should be classified as living or non-living.5 Are any of the items in Table 2.2 dead? Explain your answer.6 A mnemonic (pronounced nem-on-ic) is a memory aid. It is an especially good way

to remember a list. A mnemonic takes the first letter of each word in a list and uses the letters to start words in a phrase. For example, the colours of the rainbow (red, orange, yellow, green, blue, indigo and violet) could be remembered using the phrase Rich Old Yankees Go Bowling In Vienna. Construct a new mnemonic to help you remember the eight characteristics of living things. You may change the order of the characteristics to help you make a phrase.

7 Apply the characteristics of a living thing to describe a bushfire.8 Is a bushfire alive? Justify your answer.9 Which characteristic is the most essential for an organism to be classified as living?

Justify your answer.10 Is there another characteristic you would include in determining alive versus

non-alive? Explain your answer.

QUESTIONS 2.1.2: CLASSIFICATION OF LIVING THINGS


animal fur and skins, items made from plant

materials like wood, and food items. Revisit

this concept regularly throughout the chapter.

Differentiation

For less able students:• Theyneedtoexperienceexamplesofthe

characteristics of living things as much as

possible. Germinating seeds in a darkened

box containing a slit for light can be

used to show that plants respond to light

and will grow towards it. An interesting

extension of this is to germinate seeds

and, after the roots have sprouted, invert

them and watch how the roots will turn

and grow downwards again over time.

For more able students:• Theymaybechallengedtoconsider

that most plastics are made using

petrochemicals, and that petrochemicals

are ‘dead’ organisms modified over time by

nature and extracted by humans. Modern

biotechnology is finding ways to produce

a wider range of materials and energy

sources using microorganisms.

SYLLABUS LINKS

OutcomesSC4-14LW relates the structure and function of living things to their classification, survival and reproductionSC4-15LW explains how new biological evidence changes people’s understanding of the world





Activity 2.1.4: The fireSC4-7WS Processing and analysing data and informationSC4-9WS Communicating

Activity 2.1.5: Dead or alive?SC4-5WS Planning investigationsSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-9WS Communicating

Learning across the curriculum• Critical and creative thinking• Literacy• Personal and social capability

Activityt: Non-living or dead?Activity 2.1.5: Dead or alive? should be developed as the

major activity of this section. Students should spend

time planning and conducting an investigation to

demonstrate that dried yeast is alive. Their tasks should

be to demonstrate that yeast:

• requireswaterandnutrition(sugar)andproducegas

(wastes)

• yeastrespondstochangesintemperature—within

narrow limits, yeast will grow much faster in warm

conditions than under cold conditions.

Common misconceptionsSome students will struggle with the concept of

distinguishing between items that are non-living and

those that are now dead, but were made from something

that was once alive. Encourage ongoing discussions

and provide examples that include clothing made from



ACTIVITY 2.1.4: THE FIRE

Is a bushfire alive or not?1 Work in a group of four, divided into pairs. One pair has to argue in favour of a fire

being alive. The other pair has to argue that it is not alive.2 Each pair has 5 minutes to come up with a list of characteristics that support

whether a fire is living or not.3 When the time is up, have a class discussion about whether a fire is alive or not,

and perhaps whether other characteristics for classifying ‘alive’ may be required.

Non-living or dead?Something classified as living needs nutrition and water, and is able to move by itself, reproduce, exchange gases, grow, respond to stimuli and produce wastes. If something doesn’t have these characteristics it would seem logical to assume that the thing is non-living.

What about something that is dead? Something dead, such as a dried flower or an Egyptian mummy, was once living; when it was alive it did have the characteristics of a living thing. Something that is non-

living, such as a computer or your watch, never had these characteristics.

All living things are made up of cells. Once that living thing dies, the cells remain, but they are no longer functioning. Dead things are usually distinguished from non-living things in that they are still made up of cells. The wood of a desk, for example, was once a living tree. If you were to examine the wood under a microscope, you would see that it is still made up of cells. A plastic chair contains no cells; it is made up of molecules of plastic. It is a non-living object. You will learn more about cells in chapter 3.

Bakers use yeast (a type of microorganism) to help their bread to rise. The yeast cells use the sugar in the dough as nutrients and produce carbon dioxide, which causes the dough to rise. Yeast can also be bought as a dry powder.

Design an experiment to determine whether or not dried yeast is still alive.

• What key features of living things can you test for?

• What variables should you keep the same (controlled variables) to ensure you have designed a fair test?

• Discuss your method and results.• Is dried yeast a living thing? How do

you know?• When you have finished, your teacher

may give you a few research questions to complete.

ACTIVITY 2.1.5: DEAD OR ALIVE?

DEEPER UNDERSTANDING Encyclopedia of Life

Edward O. Wilson, one of the world’s most well-known biologists, has taken on the seemingly impossible task of compiling a list of the nearly 2 million known species on our planet. He is developing an online database of all life on the Earth. The Encyclopedia of Life (EOL) aims to make all knowledge of the world’s known species freely available to all. The initiative was

launched on 9 May 2007. As new species are discovered they will be added to the database. Every species will have its own page, with links to all known information about that species.

The EOL will be a tool not only for scientists but also for students, teachers and the public to gain a better understanding of all life on the Earth.

Remember1 The system scientists use to group things divides them first into two groups.

Identify these two groups.2 Apart from the eight characteristics of life, identify one other thing that all

living things have in common.3 Explain how to distinguish a non-living object from something that is dead,

and how to distinguish a living thing from a dead thing.

apply4 Consider Table 2.2.

Table 2.2 living or non-living?

Eucalypt tree

Water Paper Robot leather belt

Wombat Roast chicken

Computer virus

Moves by itself

Reproduces itself

Requires nutrition

Grows as it gets older

Responds to changes in its environment

Exchanges gas (e.g. oxygen)

Produces wastes

Requires water

living or non-living?

a With a partner or by yourself, decide if each of the items meets the requirement to be classified as a living thing.

b Decide if each should be classified as living or non-living.5 Are any of the items in Table 2.2 dead? Explain your answer.6 A mnemonic (pronounced nem-on-ic) is a memory aid. It is an especially good way

to remember a list. A mnemonic takes the first letter of each word in a list and uses the letters to start words in a phrase. For example, the colours of the rainbow (red, orange, yellow, green, blue, indigo and violet) could be remembered using the phrase Rich Old Yankees Go Bowling In Vienna. Construct a new mnemonic to help you remember the eight characteristics of living things. You may change the order of the characteristics to help you make a phrase.

7 Apply the characteristics of a living thing to describe a bushfire.8 Is a bushfire alive? Justify your answer.9 Which characteristic is the most essential for an organism to be classified as living?

Justify your answer.10 Is there another characteristic you would include in determining alive versus

non-alive? Explain your answer.

QUESTIONS 2.1.2: CLASSIFICATION OF LIVING THINGS


thing will demonstrate the eight characteristics of life: movement, reproduction, need for nutrition, growth, response to stimuli, gas exchange, require water and produce wastes. A dead thing will no longer do these things.

4 a See appendix page 104

b The eucalypt tree and the wombat both have all the characteristics of living things. Water is non-living and exhibits few of the characteristics of living things but it does respond to changes in the temperature of the environment: heating and cooling causes it to change state, and gases dissolve into and come out of solution. Paper, the leather belt, a robot and roast chicken are non-living and exhibit none of the characteristics of living things. Robots may move and respond to changes in their environment, but only do so under ‘instructions’ from an operator, not by themselves. Some computer viruses can reproduce and respond to changes by infiltrating other systems of your computer. However, it does not require nutrients or water. It does not exchange gases or produce wastes, and is not a living thing.

5 The roast chicken is dead because it once had all the characteristics of a living thing. Paper was once part of a plant, and leather comes from the hide of an animal, so they are part of something that is dead.

6 Student responses will vary, but must include all eight characteristics of living things.

7 A bushfire has all the characteristics of living things except ‘requires water’ and ’grows as it gets older’.

8 A bushfire is non-living because is does not require water. If water is applied to fire, it will extinguish it.

9 Student responses will vary, but must provide a logical argument to support their decision.

10 The presence of cells is another determinant of a living thing.

Activity: Database of living thingsStudents construct their own database of the

characteristics of living things, with examples

in the fields and photographs included.

Extension activitY: Extraterrestrial lifeScientists have conducted a number

of projects to search for evidence of

extraterrestrial life. Students could research

one such project and the factors they regard

as evidence of life beyond the Earth.

ANSWERS

QUESTIONS 2.1.2 Classification of living things1 The two groups scientists divide all things

into are living and non-living.

2 All living things are made from cells. This can be used as a key characteristic to identify a living or dead thing from a non-living thing.

3 A non-living object can be distinguished from a dead object by the fact that the dead object will be made up of cells, while the non-living object will not have cells. A living

TEACHER OBOOK EXTRASRisk assessment: Activity 2.1.4: The fire

> Editable risk assessment of the activity written by a qualified and experienced laboratory technician

Interactive: Classifying as living, non-living or dead

> Interactive task where students drag and drop items to classify them as living, non-living or dead

Risk assessment: Activity 2.1.5 Dead or alive?


Weblink: Encyclopedia of Life

> Links students to the website of the Encyclopedia of Life

RESOURCES



Figure 2.13 Echidnas are adapted to eating ants and termites.

Plants and animals need to be suited to the area where they live if they are to have the best chance of survival. The survival of a species relies not only on the individuals of the population living healthy lives, but also their ability to reproduce healthy offspring. We say that they are adapted to live in these areas. The features that help them survive are called adaptations. Adaptations are key features of an organism and are often used to classify and identify them.

Adaptations can be physical, like the thick fur on a platypus’s body to keep it warm, or behavioural, such as foraging for food at night to avoid predators. Adaptations can be to do with successful mating or rearing of offspring. Most adaptations help an organism to function more effectively or efficiently in some way.

Plant adaptationsPlants also have many adaptations. Many rainforest plants have shiny, waxy leaves with a ‘drip tip’ on the end to drain the rainwater quickly. The rainforest soil is usually shallow, so the bigger trees have buttress roots to help prevent them from being blown over in a strong wind. Desert plants need to lose as little water as possible during the hot days but gain as much water as possible when it rains. Some desert plants have small, rolled-up leaves, which do not get as hot as large, flat leaves. Other desert plants have spiky leaves or leaves covered with small hairs. These physical adaptations prevent the leaves from getting too hot and from losing too much water.

Perhaps the most spectacular adaptation is that of Australian plants to the dry conditions in Australia. Plants can neither run nor hide from fire as it comes sweeping through the bush. Their ability to handle fire sets them apart from plants of other regions in the world. Not only are some of our plants adapted to fire, some plants cannot exist without it.

Many eucalypt trees can reshoot after damage by fire. The trees shoot from buds

ADAPTATIONS FOR SURVIVAL AND REPRODUCTION

ACTIVITY 2.1.6: DESIGNING AN ANIMAL

Design an animal that fits the following description. Try not to base your animal on any that you already know—consider this an alien. Present a labelled diagram to the class, explaining how the various features of your animal make it suited to its lifestyle.

Waking as the sun goes down, this small animal climbs nimbly through the trees, trying to avoid detection by making sure it doesn’t rustle leaves. It cleverly taps the bark of tree trunks, checking for hollow spots where it is most likely to find insect nests hidden beneath the surface. With skill and agility, it creates an opening and sucks the insects out, feasting for several minutes before moving on. As the sun begins to return, this animal becomes invisible to the predators of the day.

Figure 2.14 The water-holding frog can survive without rain for up to seven years.

Figure 2.15 Emperor penguins huddle together to stay warm.

Figure 2.16 The blue quandong has buttress roots to help prevent it from being blown over.

Figure 2.18 These eucalypts have resprouted after fire from epicormic buds under their bark.

Figure 2.17 Cactus plants have spikes or hairy leaves to prevent them from losing too much water.

Animal adaptationsThe echidna has strong claws, which it uses to dig for termites and ants. Its snout can smell and feel for its prey, and its sticky tongue catches the termites and ants inside their nests. Having no teeth, the echidna instead crushes its food between the roof of its mouth and the base of its tongue. The soil drawn in with the termites and ants also helps with the crushing.

Echidnas have two types of hair: the obvious type being sharp spines for defence against predators, the other is fur-like hair for insulation. The echidna lays eggs like birds and reptiles but carries them in a pouch like a marsupial. This adaptation allows the female echidna to continue foraging for food while incubating eggs and caring for the immature young.

The long snouts, sticky tongues, toothless mouths, claws for digging, spines for defence and egg laying are all physical adaptations that increase the

echidnas’ chance of survival in their environment.

The water-holding frog of central Australia lives in an environment where rainfall is unpredictable and the climate is harsh. It wraps itself in a cocoon of dead skin cells and buries itself underground. Water is stored in the bladder or in pockets under the skin. The frog can spend up to seven years underground without water. After heavy rain, the frog comes to the surface, refills its water supplies, mates, feeds and then burrows again until the next rains.

Several animals demonstrate very interesting behavioural adaptations. Male emperor penguins huddle in large groups to protect themselves from the extremely cold winds in Antarctica. They take turns being on the outside to give everyone the best chance of survival. Many of these penguins hold an egg on top of their feet at the same time, protecting it from the freezing temperature of the ice below.

ACTIVITY 2.1.7: EUCALYPT ADAPTATIONS

What you need: nuts, leaves and bark of a eucalypt

1 Place the nuts in a 40ºC oven for 24 hours to open and shed their seeds. Each of these thick woody capsules contains hundreds of tiny seeds.• Why is the seed of the gumnut protected with such a thick external capsule?• What might trigger the release of the seed from the gumnut?

2 Feel the leaves of the eucalypt. They have a thick cuticle that is effective in preventing water loss.• Why would this be an advantage to the plant?

3 Hold a leaf up to the light or under a binocular microscope. Notice the numerous small dots. These are oil glands in the leaf.• What is the function of the oil glands in a eucalypt leaf?

4 Have a close look at the bark of the tree. In a lot of eucalypt trees it is thick and fibrous.• What are some of the functions of bark?• Explain how all of these adaptations you have examined help the eucalypt to

survive in Australian climates.

that are found just below the bark called epicormic buds. They can also shoot from large underground rootstock called lignotubers. Other Australian plants, like the woollybush of Western Australia, have fire resistant seeds. While the adult trees burn, the seeds are protected. They sprout after the next heavy rains and germinate in soil that is very fertile thanks to the ashes of the previous generation. Banksia seeds often cannot germinate (sprout) unless they have been exposed to the extreme heat of a bushfire. However, these plants often take many years to mature. So if there is another fire before they are old enough to produce their own seeds, that species may be wiped out in that area.


Acitivity: Reseraching Australian plants and animalsThe examples of adaptations in the text

are ideal models for students to use to

research and present their own examples of

adaptations of Australian plants and animals

to environmental conditions. This task could

be set as an assessment (literacy is a stated

Learning Across the Curriculum item for this

syllabus content).

Spend time getting students to brainstorm the

range of issues in Australian environments

that pose problems for the survival of plants

and animals. In follow-up discussions, make

students aware of infertile soils as well as

droughts, floods, bushfires, and, in only

restricted areas, low temperatures. Include

environments such as estuaries in which there

are extreme variations of salinity. Students

need to be aware that organisms must be

adapted to compete for reproduction, food

and shelter, no matter how difficult the

physical environment may be.

Encourage students to present their work as

a poster or electronically in a form that can

readily be shared and peer evaluated.

Starter activity: Adaption for survival and reproductionStudents could undertake group research using

secondary sources. Choose one feature of living

things, for example, ‘fly’ or ‘glide’, and research all the

different adaptations that help organisms fly or glide.

Alternatively, students could choose one organism and

research its features, and determine how those features

contribute to the living thing’s success in a particular

environment.

Working in groups, give students an identical

mass of plasticine and a 500 mL measuring cylinder

filled with water. Students have to shape the plasticine

into a creature that needs to swim fast to escape a

predator. Student groups compete against each other by

releasing their creature at the surface of the water in the

measuring cylinder—the one that is fastest to the bottom

wins. Students discuss the winning design.

SYLLABUS LINKS


Knowledge and understandingLW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).Students:b classify a variety of living things based on

similarities and differences in structural features



Activity 2.1.6: Designing an animalSC4-7WS Processing and analysing data and informationSC4-8WS Problem solvingSC4-9WS Communicating

Activity 2.1.7: Eucalypt adaptationsSC4-4WS – Questioning and predictingSC4-6WS – Conducting investigationsSC4-7WS – Processing and analysing data and informationSC4-9WS – Communicating


































Differentiation

For less able students:• Themainactivitywillbedemanding

for students with low ability or literacy

problems. Scaffolding will need to be

provided. Encourage students to use

labelled diagrams to convey information.

A T-chart to support the communication

of cause and effect relationships may also

be useful. These students may also need

support to find resources at a suitable level.

of wood, the capsule protects the seed from drying out. The release of the seeds could results from the death of the plant. (Banksia is the group (genus) that generally releases seeds in response to fire.)

• The cuticle is a thick waxy layer that helps prevent water from evaporating from the leaf. This is an advantage to eucalypt trees, which usually live in very arid (dry) environments.

• The function of the oil glands is to store and release oil. The oil deters herbivores and could help the leaf remain rigid in dry times. A waxy surface reduces evaporation from the leaf surface.

• The thick persistent bark of some eucalypts could protect the tree from the heat of fire. The vascular bundles of the plant are close to the bark, and these tissues are vital for the function and survival of the plant.

• Structuredgroupwork(asopposedto

student-selected groups) can help if it has

a cooperative structure and the students

do not just rely on more able students to

submit the work.

ANSWERS

ACTIVITY 2.1.7 Eucalypt adaptations• The gumnut is a woody capsule that

can store the seed for a great length of time. (Fleshy fruits, such as oranges, rapidly decompose and no longer serve as protection for the seeds.) Being made

TEACHER OBOOK EXTRAS > Weblink: Effect of bushfires in Australian plants > Weblink: Eucalypts have a special way of

regrowing after fire w > Weblink: Graphic organisers such as T-charts

STUDENT OBOOK EXTRAS > Risk assessment: Activity 2.1.6 Designing an

animal > Editable risk assessment of the activity written


> Risk assessment: Activity 2.1.7 Eucalypt adaptations


RESOURCES



Different heights = variation Favourable variations surviveto reproduce

Only favourable variation left

Different heights = variationOnly favourable variation left

Favourable variations survive to reproduce Only favourable variation left



Different heights = variation



Different heights = variation Favourable variations survive

to reproduce

Only favourable variation leftDifferent heights = variation Only favourable variation leftFavourable variations

survive to reproduce Only favourable variation left

Living fossilsEnvironments can change naturally, and they can be changed by humans. This places new environmental conditions on existing adaptations. Changing environmental conditions may no longer suit the adaptations of an organism, which may cause the organism to die. If no members of the population or species are suited to their new environments then the whole species might become extinct. However, some isolated habitats might remain favourable so that some organisms of a species can survive, even though everywhere else around has changed.

During 1994, material was collected from a strange-looking tree growing in a deep gorge within Wollemi National Park in the Blue Mountains in New South Wales. The total population of 40 adult trees and 130 seedlings all existed in this one gorge. The tree turned out to be a very old species, which was named the Wollemi pine. It is one of the oldest and rarest plants, dating back to the time of the dinosaurs. The Wollemi pine shows that some isolated animals and plants can survive almost unchanged if the conditions they are living in don’t change.

DEEPER UNDERSTANDING

Figure 2.19 A Wollemi pine in the Wollemi National Park.

How adaptations arisePhysical adaptations rely on variation already existing in a population. If food was running out and there was the possibility of getting food from the top of a tree, an animal might be able to teach itself to climb but it certainly couldn’t just grow longer legs or a longer neck.

You might have heard of the phrase ‘survival of the fittest’. This has very little to do with being able to run a race. In this phrase, being ‘fit’ means ‘suited to the environmental conditions’. Looking around your classroom, you will notice that even though you’re all human and about the same age, you’re all slightly different. This is a really good thing because it means you all have strengths and weaknesses in different ways. The same applies to all organisms.

In a population of animals that are all of slightly different heights, perhaps some will be able to reach the food at the top of a tree. This might mean that everyone gets to eat or it might mean that only those that are tall enough to reach this food get to eat. Either way, if you eat, you live long enough to reproduce, passing your features to the next generation. If you don’t eat, you probably won’t live long enough to reproduce and your particular features may be lost from

the population. Over time, if the food availability stays the same, the population is likely to become taller because only the tall members of the species are reproducing.

Physical adaptations may take a long time to happen and so many species face extinction if their population doesn’t adapt fast enough.

Figure 2.21 No two individuals within a species are exactly the same.

Figure 2.20 Variations provide options for species when environments change.

Thinkers’ keysThinkers’ Keys (by Tom Ryan) are strategies that challenge us to think in different ways. Try using the Thinkers’ Keys approach to think differently about life on the Earth.The reverse listing keyName ten things that a non-living thing could never do.The ‘what if’ keyWhat if living things did not exist? What would the Earth be like?The question keyThe answer is ‘single-celled organism’. Think of five questions that give only that answer.The construction keyUse materials from around your classroom to construct your own type of classification key.

The combination keyMake a list of all of the attributes of plants and animals. Combine the attributes of these two things to create a new and better type of organism.The disadvantages keyMake a list of the possible disadvantages of classifying things into groups. Suggest ways to correct or eliminate each disadvantage.The prediction keyPredict what types of organism might be discovered in the next 20 years.The alphabet keyPrepare a list of words from A to Z that describe things that a living thing can do.The commonality keyWhat do living things and non-living things have in common?


Remember1 Explain what ‘adaptation’ means.2 Identify some features of desert plants that are adaptations.3 Identify the differences between behaviour adaptations and physical adaptations.4 Define the term ‘lignotubers’.

apply5 Explain how adaptations help an animal to survive.6 Investigate how these adaptations of a bilby are useful:

a nocturnalb lives in a burrowc large earsd very concentrated urine.

7 Suggest reasons to explain why a species or population with a long life cycle is likely to take much longer to physically adapt to an environmental change than the same one with a short life cycle.

8 Tabulate all the adaptations mentioned in this section, ensuring that you identify each adaptation as either chemical, behavioural, structural or otherwise.

Research9 Research some other examples of living fossils. Present your research in the form

of a pamphlet.

QUESTIONS 2.1.3: ADAPTATIONS FOR SURVIVAL AND REPRODUCTION


SYLLABUS LINKS



Students:f explain how the features of some Australian

plants and animals are adaptations for survival and reproduction in their environment

Learning across the curriculum• Critical and creative thinking• Literacy

the possible effects of climate change

on Australian ecosystems. Discuss the

implications for maintaining biodiversity in

Australia.

ANSWERS

QUESTIONS 2.1.3 Adaptations for survival and reproduction1 An adaptation is a feature that helps

an organism survive in a particular environment.

2 Some features of desert plants that are adaptations are:

• anextensiverootsystemsothatanywater in the area can be absorbed by the plant

• smallleaves,needle-likeorcurved,to reduce the area of the underneath surface so that water loss through the leaves is minimal and the leaves do not absorb much heat from the sun; needle-like leaves may be an added protection from herbivores, which may want to eat the plant for nutrition or water

• hairyorsilveryleavestoreflectheatand retain moisture around the leaf

• aconicalshapesothatdeworother

Activity: How adaptations ariseA common way to teach the concept of natural

selection is to model the process. Some students could

be ‘predators’ and others ‘prey’. Some students in both

groups could have their movement restricted by having

their own feet tied together. The predators see how many

prey they can tag. Tally the number of prey the predators

catch and compare the results of the tied predators with

the untied predators. Did any of the prey escape, and if

so were they tied or not? Discuss results.

Differentiation

For more able students:• Thesestudentsmaynotbesatisfiedwiththesimple

explanation of Darwin’s theory of natural selection

in the text ‘How adaptations arise’ Set a research

task to get students to investigate how sexual

reproduction results in variation in populations.

Activity: Designing adaptionsStudents choose one of their favourite activities—either

sport or cultural, but it must involve some physical

skills. They think about the skills needed for this activity

and suggest changes to the human body (physical

adaptations) or behavioural adaptations that would help

them perform the named task better. Students could

draw and label a diagram of their ‘adapted human’,

display them around the room and then share their

ideas in a gallery walk.

Extension activity Biodiversity in AustraliaThe Deeper Understanding activity about the Wollemi

pine is relevant to many current discussions about





Different heights = variationOnly favourable variation left




Different heights = variation



Different heights = variation Favourable variations survive

to reproduce

Only favourable variation leftDifferent heights = variation Only favourable variation leftFavourable variations

survive to reproduce Only favourable variation left

Living fossilsEnvironments can change naturally, and they can be changed by humans. This places new environmental conditions on existing adaptations. Changing environmental conditions may no longer suit the adaptations of an organism, which may cause the organism to die. If no members of the population or species are suited to their new environments then the whole species might become extinct. However, some isolated habitats might remain favourable so that some organisms of a species can survive, even though everywhere else around has changed.

During 1994, material was collected from a strange-looking tree growing in a deep gorge within Wollemi National Park in the Blue Mountains in New South Wales. The total population of 40 adult trees and 130 seedlings all existed in this one gorge. The tree turned out to be a very old species, which was named the Wollemi pine. It is one of the oldest and rarest plants, dating back to the time of the dinosaurs. The Wollemi pine shows that some isolated animals and plants can survive almost unchanged if the conditions they are living in don’t change.


Figure 2.19 A Wollemi pine in the Wollemi National Park.

How adaptations arisePhysical adaptations rely on variation already existing in a population. If food was running out and there was the possibility of getting food from the top of a tree, an animal might be able to teach itself to climb but it certainly couldn’t just grow longer legs or a longer neck.

You might have heard of the phrase ‘survival of the fittest’. This has very little to do with being able to run a race. In this phrase, being ‘fit’ means ‘suited to the environmental conditions’. Looking around your classroom, you will notice that even though you’re all human and about the same age, you’re all slightly different. This is a really good thing because it means you all have strengths and weaknesses in different ways. The same applies to all organisms.

In a population of animals that are all of slightly different heights, perhaps some will be able to reach the food at the top of a tree. This might mean that everyone gets to eat or it might mean that only those that are tall enough to reach this food get to eat. Either way, if you eat, you live long enough to reproduce, passing your features to the next generation. If you don’t eat, you probably won’t live long enough to reproduce and your particular features may be lost from

the population. Over time, if the food availability stays the same, the population is likely to become taller because only the tall members of the species are reproducing.

Physical adaptations may take a long time to happen and so many species face extinction if their population doesn’t adapt fast enough.

Figure 2.21 No two individuals within a species are exactly the same.

Figure 2.20 Variations provide options for species when environments change.

Thinkers’ keysThinkers’ Keys (by Tom Ryan) are strategies that challenge us to think in different ways. Try using the Thinkers’ Keys approach to think differently about life on the Earth.The reverse listing keyName ten things that a non-living thing could never do.The ‘what if’ keyWhat if living things did not exist? What would the Earth be like?The question keyThe answer is ‘single-celled organism’. Think of five questions that give only that answer.The construction keyUse materials from around your classroom to construct your own type of classification key.

The combination keyMake a list of all of the attributes of plants and animals. Combine the attributes of these two things to create a new and better type of organism.The disadvantages keyMake a list of the possible disadvantages of classifying things into groups. Suggest ways to correct or eliminate each disadvantage.The prediction keyPredict what types of organism might be discovered in the next 20 years.The alphabet keyPrepare a list of words from A to Z that describe things that a living thing can do.The commonality keyWhat do living things and non-living things have in common?


Remember1 Explain what ‘adaptation’ means.2 Identify some features of desert plants that are adaptations.3 Identify the differences between behaviour adaptations and physical adaptations.4 Define the term ‘lignotubers’.

apply5 Explain how adaptations help an animal to survive.6 Investigate how these adaptations of a bilby are useful:

a nocturnalb lives in a burrowc large earsd very concentrated urine.

7 Suggest reasons to explain why a species or population with a long life cycle is likely to take much longer to physically adapt to an environmental change than the same one with a short life cycle.

8 Tabulate all the adaptations mentioned in this section, ensuring that you identify each adaptation as either chemical, behavioural, structural or otherwise.

Research9 Research some other examples of living fossils. Present your research in the form

of a pamphlet.

QUESTIONS 2.1.3: ADAPTATIONS FOR SURVIVAL AND REPRODUCTION


Being nocturnal may assist the bilby to catch some of its prey.

b Living in a burrow means the bilby avoids the extremely high daytime temperatures, which helps them manage body temperature without the need to drink.

c Large ears may help the bilby to detect the direction of sound, but they are more likely to help the bilby dissipate excess body heat.

d Very concentrated urine helps reduce the bilby’s need for water.

7 Organisms with a long life cycle will have longer intervals between generations. This means those that are better suited to the environment and more are likely to survive and reproduce will take longer to produce offspring, which eventually changes the characteristics of the population.

8 Students responses will vary but the following table can be used as a guide. See Appendix page 105.

9 Student responses will vary.

moisture is drawn down to the base of the stem

• theabilitytostorewaterwithintheirstems or trunks.

3 Behaviour adaptations are the actions that an organism performs, while physical adaptations are the structural features of that organism.

4 A lignotuber is a very large rootstock of a tree and is found underground. It contains lots of nutrients and is able to resprout to repair the tree after significant damage, such as from fire.

5 Adaptations may assist an organism

to obtain nutrition, avoid predation, find shelter or better attract a mate. Adaptations may help an organism survive the rigours of their environment such as extreme cold, extreme heat, lack of water, intense sunlight, dull sunlight, wind, or the movement of water or ice.

6 Bilbies live in desert conditions in inland Australia.

a Being nocturnal means the animal is active when conditions are not so hot, so it does not risk dehydration. Bilbies eat insects (adults and larvae), spiders, fruit, seeds, fungi or small animals.

TEACHER OBOOK EXTRAS

> Weblink: Variation and classification activity > Interactive task where students learn about the

process of adaption that arises through genetic variation

> Weblink: Anangu environmental conditions > Uluru-Kata Tjuta National Park website, where

students can research the environmental conditions of the Anangu land that drive adaptation for local species

> Weblink: Fauna of Uluru-Kata Tjuta National park

> Ayres Rock Resort website, where students can research information about and specific adaptations of local bird, reptile, mammal and invertebrate species

> Weblink: Plants and animals of arid Australia > The Friends of the Australian Arid Lands

Botanic Garden website, where students can research information about and specific adaptations of arid environment plants and animals.

RESOURCES



Remember and understand1 Identify the eight characteristics of

living things. [1 mark]

2 Define organism. [1 mark]

3 Outline the key differences between something that is dead (i.e. once living) and something that is non-living. [1 mark]

4 Describe an example of plant movement. [1 mark]

5 Recall what a living plant needs to survive. [1 mark]

6 Explain why it is important for scientists to use a common system to group all living things on the Earth. [1 mark]

7 Recall some adaptations that eucalypts have to help them survive fires. [1 mark]

8 Copy the table shown. Classify the items in the following list by placing them in the correct columns: stewed apple, iPod, daffodil bulb, DVD, hairs in your brush, your teacher, shark’s tooth, germs, soft drink bottle, your pet, silver chain, dinosaur skeleton [3 marks]

livingnon-living

Currently living Dead

apply9 Plants are autotrophs (i.e. they make

their own food), so why do they need other nutrients? Explain your answer. [2 marks]

10 Possums (Figure 2.22) come out at night and move around in trees. Identify what type of adaptation this is. Examine what other examples of adaptation they might have to support their survival. [2 marks]

11 Imagine that an unknown organism was discovered during a space mission and brought back to Earth. Briefly outline two different methods that scientists could use to decide if it was living or non-living. [2 marks]

12 Drawing accurate scientific diagrams of plants and animals is time consuming and difficult. Describe what method scientists would use today to show what an organism looks like. [1 mark]

13 A tapeworm (Figure 2.23) has many unusual adaptations. Suggest a reason for the following adaptations:

a hooks around its ‘head’ [1 mark]

b suckers [1 mark]

c its flat body [1 mark]Figure 2.23

Figure 2.22

Research17 Do an Internet search for an image of

a recently discovered species. Can you use the Internet to find how scientists classified the species (i.e. its scientific name)? [1 mark]

18 One of the main contributors to the Encyclopedia of Life is the Atlas of Living Australia. Do an Internet search for the Atlas of Living Australia and click on ‘Explore’. From this page you can construct a species list and map for the area in which you live.

a Investigate the most frequently seen animal in your area. [1 mark]

b Identify the most frequently seen plant in your area. [1 mark]

Critical and creative thinking19 Design an experiment to show that

plants are living things that respond to stimuli. Choose one stimulus only

(such as reaction to light or to lack of water) to investigate. This stimulus is the experimental variable, so you will need to change the variable in some way and control the rest of the variables in the experiment. Make a list of the equipment you would need. Describe any safety guidelines you need to follow. [5 marks]

20 Write a short story of 500 words to describe the chaos in a large library that operated with no system of classification. Try to make it humorous. [5 marks]

Making connections21 Investigate why the invention of the

microscope was important to the development of the classification system. How did it change the number of organisms for identification, classification and communication? [5 mark]

Table 2.3 Types and numbers of living things on the Earth.

group number of species described

number of species estimated to exist

Percentage of total estimated number of living things (%)

Animals with internal backbones (vertebrates) 64 788 80 500 0.7

Animals without backbones (invertebrates) 1 359 365 6 755 830 61.8

Plants 297 857 390 800 3.6

Fungi 98 998 1 500 000 13.7

Bacteria (monerans) 35 351 >1 200 500 11

Algae and protozoa (protists) 28 871 >1 000 000 9.2

Total number of species 1 885 230 >10 927 630 100

Source: Chapman, A.D., Numbers of Living Species in Australia and the World, 2nd ed., September 2009

analyse and evaluate14 Suggest at least two reasons why we

need to classify living things. [2 marks]

15 Explain how adapting to the environment helps a species reproduce and survive. [2 marks]

16 Look at Table 2.3, showing the number of living things on the Earth.

a Identify how many species of plant are estimated to be on the Earth. [1 mark]

b Compare the number of known plant species with the total number of known animal species (add animals without a backbone and animals with a backbone together). Why do you think this might be the case? Explain your reasoning. [2 marks]

CLASSIFYING LIVING THINGS

TOTal MaRKS [ /45]

2.1CHECKPOINT

64 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4 652.1 ClaSSIFyIng lIvIng ThIngS

SYLLABUS LINKS

OutcomesSC4-14LW relates the structure and function of living things to their classification, survival and reproductionSC4-15LW explains how new biological evidence changes people’s understanding of the world





Working scientificallySC4-4WS Questioning and predictingSC4-7WS Processing and analysing data and informationSC4-9WS Communicating

Learning across the curriculum• Critical and creative thinking• Literacy

ANSWERS

CHECKPOINT 2.1 Classifying living things1 The eight characteristics of living things are

movement, reproduction, nutrition requirement, growth as they get older, response to stimuli, exchange of gases with their environment, production of wastes and water requirement.

2 An organism is a living thing that has (or can develop) the ability to act or function independently. It can react to stimuli, reproduce, grow and maintain a stable internal environment. It can be a bacterium, protist, fungus, plant or animal. Viruses are not regarded as organisms because they require a living host cell to reproduce.

3 ‘Dead’ refers to something that was once living. ‘Non-living’ refers to something that has never been alive, such as rocks.

4 Student responses will vary but may include that sunflowers turn their ‘heads’ to follow the sun and leaves face the sunlight.

5 A living plant needs nutrition such as water and carbon dioxide, and minerals from the soil such as nitrates, potassium and phosphates.

6 It is important for scientists to use a common system to group all living things because they may inadvertently identify the same organism in a different way. Also, it is easier for scientists to infer something about one species when a similar species has already been classified.

7 Eucalypts have bark that protects from fire and woody seed capsules to protect seeds from heat and dehydration.

8 Non-living: iPod, DVD, soft drink bottle, silver chain; Currently living: daffodil bulb, your teacher, your pet, germs; Dead: stewed apple, shark’s tooth, dinosaur skeleton, hairs in your brush.

9 Plants exchange oxygen and carbon dioxide with their environment during photosynthesis. They require minerals to convert carbohydrate molecules into other substances such as proteins.

10 Being nocturnal is a behavioural adaptation. Other adaptations could include the presence of whiskers to sense the surroundings in the dark, fur to maintain body temperature and a prehensile tail for climbing.

11 Scientists would need to identify whether the organism had all the characteristics of a living thing, such as whether it breathes, moves by itself, needs nutrition,



Remember and understand1 Identify the eight characteristics of

living things. [1 mark]

2 Define organism. [1 mark]

3 Outline the key differences between something that is dead (i.e. once living) and something that is non-living. [1 mark]

4 Describe an example of plant movement. [1 mark]

5 Recall what a living plant needs to survive. [1 mark]

6 Explain why it is important for scientists to use a common system to group all living things on the Earth. [1 mark]

7 Recall some adaptations that eucalypts have to help them survive fires. [1 mark]

8 Copy the table shown. Classify the items in the following list by placing them in the correct columns: stewed apple, iPod, daffodil bulb, DVD, hairs in your brush, your teacher, shark’s tooth, germs, soft drink bottle, your pet, silver chain, dinosaur skeleton [3 marks]

livingnon-living

Currently living Dead

apply9 Plants are autotrophs (i.e. they make

their own food), so why do they need other nutrients? Explain your answer. [2 marks]

10 Possums (Figure 2.22) come out at night and move around in trees. Identify what type of adaptation this is. Examine what other examples of adaptation they might have to support their survival. [2 marks]

11 Imagine that an unknown organism was discovered during a space mission and brought back to Earth. Briefly outline two different methods that scientists could use to decide if it was living or non-living. [2 marks]

12 Drawing accurate scientific diagrams of plants and animals is time consuming and difficult. Describe what method scientists would use today to show what an organism looks like. [1 mark]

13 A tapeworm (Figure 2.23) has many unusual adaptations. Suggest a reason for the following adaptations:

a hooks around its ‘head’ [1 mark]

b suckers [1 mark]

c its flat body [1 mark]Figure 2.23

Figure 2.22

Research17 Do an Internet search for an image of

a recently discovered species. Can you use the Internet to find how scientists classified the species (i.e. its scientific name)? [1 mark]

18 One of the main contributors to the Encyclopedia of Life is the Atlas of Living Australia. Do an Internet search for the Atlas of Living Australia and click on ‘Explore’. From this page you can construct a species list and map for the area in which you live.

a Investigate the most frequently seen animal in your area. [1 mark]

b Identify the most frequently seen plant in your area. [1 mark]

Critical and creative thinking19 Design an experiment to show that

plants are living things that respond to stimuli. Choose one stimulus only

(such as reaction to light or to lack of water) to investigate. This stimulus is the experimental variable, so you will need to change the variable in some way and control the rest of the variables in the experiment. Make a list of the equipment you would need. Describe any safety guidelines you need to follow. [5 marks]

20 Write a short story of 500 words to describe the chaos in a large library that operated with no system of classification. Try to make it humorous. [5 marks]

Making connections21 Investigate why the invention of the

microscope was important to the development of the classification system. How did it change the number of organisms for identification, classification and communication? [5 mark]

Table 2.3 Types and numbers of living things on the Earth.

group number of species described

number of species estimated to exist

Percentage of total estimated number of living things (%)

Animals with internal backbones (vertebrates) 64 788 80 500 0.7

Animals without backbones (invertebrates) 1 359 365 6 755 830 61.8

Plants 297 857 390 800 3.6

Fungi 98 998 1 500 000 13.7

Bacteria (monerans) 35 351 >1 200 500 11

Algae and protozoa (protists) 28 871 >1 000 000 9.2

Total number of species 1 885 230 >10 927 630 100

Source: Chapman, A.D., Numbers of Living Species in Australia and the World, 2nd ed., September 2009

analyse and evaluate14 Suggest at least two reasons why we

need to classify living things. [2 marks]

15 Explain how adapting to the environment helps a species reproduce and survive. [2 marks]

16 Look at Table 2.3, showing the number of living things on the Earth.

a Identify how many species of plant are estimated to be on the Earth. [1 mark]

b Compare the number of known plant species with the total number of known animal species (add animals without a backbone and animals with a backbone together). Why do you think this might be the case? Explain your reasoning. [2 marks]

CLASSIFYING LIVING THINGS

TOTal MaRKS [ /45]

2.1CHECKPOINT

64 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4 652.1 ClaSSIFyIng lIvIng ThIngS

can reproduce, grows as it gets older, responds to stimuli, exchanges gases with the environment, produces wastes and requires water (two of these would be required). This might be especially challenging to do for an organism from space because it may have unique ways of fulfilling the characteristics or it may be in a state of hibernation. Scientist could place it in sealed atmosphere and monitor changes in levels of gases or water vapour.

12 Today, scientists commonly use photography or videos to show what an organism looks like.

13 a/b The hooks and suckers on atapeworm are probably adaptations for the organism to hold on to the digestive system that it parasitises. The normal muscle contractions that force food through a digestive system would otherwise expel the tapeworm, and it would lose its host.

c A flat body allows it to move easily through the digestive system and increases its body-to-surface area ratio, which increases the rate at which it can absorb nutrients from the host.

14 Student responses will vary but may include that classification makes

communicating about species much easier between different scientists and that it enables scientists to predict the structure and function of similar species.

15 Adapting makes a species better suited to its environment. Adaptations may enable the organisms to gather food and protect themselves more effectively. This in turn increases their chance of survival and likelihood of reproduction.

16 Refer to Table 2.3.

a It is estimated that in excess of 390 800 species of plant live on the Earth.

b Animals on the Earth = 1 424 153; plants on the Earth = 297 857. Animals have the ability to move around and change their habitat if required, while plants must remain where they grow. Animals tend to breed more quickly than plants and so will adapt more quickly to their environment, creating more different species.

17 Student responses will vary. An example is the recent discovery by Dr Jodi Rowley, from the Australian Museum, of a frog in Vietnam. The vampire flying frog Rhacophorus vampyrus is highly unusual, as its name suggests. When conducting searches such as this, students should learn to use recognised scientific organisations as their information sources.

18 Answers will vary depending on the area.

19 Student responses will vary—students could design an experiment in which plants are planted faced away from light so the leaves turn to face the light. They could also investigate how plants respond to different amounts of daily watering.

20 Student responses will vary but a key point should be that it is almost impossible to locate items.

19 The invention of the microscope was important to the development of the classification system because it had a big impact on scientific thinking. Very small organisms were discovered that did not fit into either the plant or animal groups. It also meant that a more systematic approach was needed to ensure all species could be included as the number of organisms requiring identification, classification and communication increased dramatically.

OVERMATTER see page 110

> This Checkpoint can be used as an indication of student progression through this chapter.

> Students who score less than 10/45 should be directed to complete Diagnostic Worksheet: Support 2.1.

> Students who score between 10/45 and 30/45 should be directed to complete Diagnostic Worksheet: Consolidate 2.1.

> Students who score more than 30/45 should be directed to complete Diagnostic Worksheet: Extend 2.1.


RESOURCES



Derwent StreetGlebeSydney

New South Wales

Australia

Southern HemisphereEarth

Solar System

Milky Way Galaxy

The Universe

23

KINGDOM: ANIMALIA

e.g. insect, fish, bird, lizard, kangaroo, fox, lion, jungle cat, domestic cat

PHYLUM: CHORDATA

e.g. fish, bird, lizard, kangaroo, fox, lion, jungle cat, domestic cat

CLASS: MAMMALIA

e.g. kangaroo, fox, lion, jungle cat, domestic cat

ORDER: CARNIVORAe.g. fox, lion, jungle cat,

domestic cat

FAMILY: FELIDAEe.g. lion, jungle cat,

domestic cat

GENUS: FELIS

e.g. jungle cat, domestic cat

SPECIES: CATUSe.g. domestic cat

USING KEYS AS TOOLS FOR CLASSIFICATIONScientists group or classify the millions of living things on the Earth so that they can see similarities and differences between organisms. This system helps scientists to communicate with each other when describing the characteristics and behaviour of living things. Once these levels of classification have been described, they can be used to identify an unknown organism.

2.2THE LINNAEAN CLASSIFICATION SYSTEM

When you were younger, did you ever send a letter to a friend with your address on the back of the envelope written like Figure 2.24?

If you read this address from the bottom up—from ‘The Universe’ to the house number—each line is like a level of classification. As you go up each level, the classification becomes more specific and the recipient becomes easier to locate. It is a bit like focusing in on your house on Google Earth.

You may start with the whole country, but each country has states, then towns, suburbs and, finally, streets and buildings.

Giving organisms a precise nameWhile many taxonomists developed different methods of classifying living things, it is the work of Swedish scientist Carolus Linnaeus from the mid-1700s that is still used today. The Linnaean Classification Hierarchy works in a similar way to the address in Figure 2.24. While the levels of the Linnaean Classification Hierarchy are relatively unchanged, the numbers of groups within each level and their defining characteristics have been and continue to be refined as research and technology improves.

The Linnaean system for classifying all living things starts with large groups called kingdoms, and then divides into smaller groups called phyla (singular: phylum). Each phylum has several classes. The classes have orders, and so on. There are seven different levels to get to the final name of each organism. They are kingdom, phylum, class, order, family, genus and species, with each level having fewer types of organisms that belong in them.

Figure 2.24 Did you ever address a letter like this?

Figure 2.25 Carolus Linnaeus

ACTIVITY 2.2.1: GROUPING ANIMALS

Locate, print and cut out the images of 20 very different animals.Decide on the most appropriate features for grouping these animals. For example,

fat and thin tends to be related to lifestyle rather than the type of animal, so it is not a good feature to use in classification.

Use these groupings to come up with a key for your animals.Did anyone in the class use similar characteristics to you when grouping their

animals? How do you think this is similar or different to the way scientists would work? Do you think your levels of classification match Linnaeus’ classification hierarchy?

Figure 2.27 Musa sapientum is the Linnaean binomial name for a banana.

Figure 2.28 Canis familiaris is the scientific name for the domestic dog.

Figure 2.26 The Linnaean classification system uses seven different levels. It is used to give scientific names to living things such as the domestic cat, Felis catus.

Linnaeus’s double-name systemHave you eaten a Musa sapientum lately? And did you pat your Canis familiaris this morning? These are the kinds of double name given to every living thing using the Linnaean classification system.

Our homes can easily be found by using only the two smallest groups in the address (the street and the suburb). The information about the bigger groups, like the Earth and the Universe, is not really necessary. In much the same way, an organism can also be named from the two last groupings on the Linnaean dichotomous key—the genus and the species.

In the double-name system, the genus group name always starts with a capital letter. The second word is the species name and it does not have a capital letter. The double name is always written using italics (sloping letters), or underlined when written by hand.

A species is a group of organisms that have similar characteristics to each other. When they breed in natural conditions, their offspring are fertile (they can also breed). All domestic dogs belong to the one species because, even though they look very different, they can breed together and have puppies.

More than 500 000 organisms have already been given a double name (also called a binomial name) and can be easily found in the Linnaean classification system.

2.2 USIng KEyS aS TOOlS FOR ClaSSIFICaTIOn 6766 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4



Knowledge and understanding LW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).Students:a identify reasons for classifying living things





Activity 2.2.1: Grouping animalsSC4-4WS Questioning and predictingSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-9WS Communicating

Learning across the curriculum • Critical and creative thinking• Literacy• Personal and social capability

book and prepares a book report, including

its reference numbers and a summary of the

contents of the book.

While in the library, students research each

level of the classification of the domestic

cat that is shown. Randomly allocate a

number between 1 and 7 and then allocate

each student number a group level, e.g.

‘order’. Each student then researches the

distinguishing characteristic of their allocated

order and some examples.

Use the example of the postal letter with its

‘hierarchical’ address and ask students to

INTRODUCING 2.2

This part of the chapter provides students with the knowledge and skills to identify some simple examples of living things. It also gives them an appreciation of the need for scientific names to ensure accurate communication.

Starter activity: The Linnaen classification systemDefine ‘hierarchy’ and get students to brainstorm

organisations and systems that have a hierarchical

structure. How is a school like a hierarchy? Students can

develop a PMI table about hierarchies.

Visit the library (organise jointly with the librarian

if possible). The books in the kingdom ‘non-fiction’

are divided into subjects (phyla). Go to the ‘science’

phylum and get students to research the subject areas

and numbers that address the whole field of science

(in the Dewey system, 500–599 includes science and

mathematics). Students find the books that refer to

biological classification. Each student selects a different

write addresses on envelopes for a book in the

biology section of the library.

Activity: The name gameLearning about the Linnaean classification

system supports students to better understand

the reasons why living things are classified.

An activity requiring students to think about

classification and naming could be helpful.

Place students randomly into groups of five.

Each group makes up a common name to

be shared for all members of the group,

which is then to be combined with a separate



Derwent StreetGlebeSydney

New South Wales

Australia

Southern HemisphereEarth

Solar System

Milky Way Galaxy

The Universe

23

KINGDOM: ANIMALIA

e.g. insect, fish, bird, lizard, kangaroo, fox, lion, jungle cat, domestic cat

PHYLUM: CHORDATA

e.g. fish, bird, lizard, kangaroo, fox, lion, jungle cat, domestic cat

CLASS: MAMMALIA

e.g. kangaroo, fox, lion, jungle cat, domestic cat

ORDER: CARNIVORAe.g. fox, lion, jungle cat,

domestic cat

FAMILY: FELIDAEe.g. lion, jungle cat,

domestic cat

GENUS: FELIS

e.g. jungle cat, domestic cat

SPECIES: CATUSe.g. domestic cat

USING KEYS AS TOOLS FOR CLASSIFICATIONScientists group or classify the millions of living things on the Earth so that they can see similarities and differences between organisms. This system helps scientists to communicate with each other when describing the characteristics and behaviour of living things. Once these levels of classification have been described, they can be used to identify an unknown organism.

2.2THE LINNAEAN CLASSIFICATION SYSTEM

When you were younger, did you ever send a letter to a friend with your address on the back of the envelope written like Figure 2.24?

If you read this address from the bottom up—from ‘The Universe’ to the house number—each line is like a level of classification. As you go up each level, the classification becomes more specific and the recipient becomes easier to locate. It is a bit like focusing in on your house on Google Earth.

You may start with the whole country, but each country has states, then towns, suburbs and, finally, streets and buildings.

Giving organisms a precise nameWhile many taxonomists developed different methods of classifying living things, it is the work of Swedish scientist Carolus Linnaeus from the mid-1700s that is still used today. The Linnaean Classification Hierarchy works in a similar way to the address in Figure 2.24. While the levels of the Linnaean Classification Hierarchy are relatively unchanged, the numbers of groups within each level and their defining characteristics have been and continue to be refined as research and technology improves.

The Linnaean system for classifying all living things starts with large groups called kingdoms, and then divides into smaller groups called phyla (singular: phylum). Each phylum has several classes. The classes have orders, and so on. There are seven different levels to get to the final name of each organism. They are kingdom, phylum, class, order, family, genus and species, with each level having fewer types of organisms that belong in them.

Figure 2.24 Did you ever address a letter like this?

Figure 2.25 Carolus Linnaeus

ACTIVITY 2.2.1: GROUPING ANIMALS

Locate, print and cut out the images of 20 very different animals.Decide on the most appropriate features for grouping these animals. For example,

fat and thin tends to be related to lifestyle rather than the type of animal, so it is not a good feature to use in classification.

Use these groupings to come up with a key for your animals.Did anyone in the class use similar characteristics to you when grouping their

animals? How do you think this is similar or different to the way scientists would work? Do you think your levels of classification match Linnaeus’ classification hierarchy?

Figure 2.27 Musa sapientum is the Linnaean binomial name for a banana.

Figure 2.28 Canis familiaris is the scientific name for the domestic dog.

Figure 2.26 The Linnaean classification system uses seven different levels. It is used to give scientific names to living things such as the domestic cat, Felis catus.

Linnaeus’s double-name systemHave you eaten a Musa sapientum lately? And did you pat your Canis familiaris this morning? These are the kinds of double name given to every living thing using the Linnaean classification system.

Our homes can easily be found by using only the two smallest groups in the address (the street and the suburb). The information about the bigger groups, like the Earth and the Universe, is not really necessary. In much the same way, an organism can also be named from the two last groupings on the Linnaean dichotomous key—the genus and the species.

In the double-name system, the genus group name always starts with a capital letter. The second word is the species name and it does not have a capital letter. The double name is always written using italics (sloping letters), or underlined when written by hand.

A species is a group of organisms that have similar characteristics to each other. When they breed in natural conditions, their offspring are fertile (they can also breed). All domestic dogs belong to the one species because, even though they look very different, they can breed together and have puppies.

More than 500 000 organisms have already been given a double name (also called a binomial name) and can be easily found in the Linnaean classification system.


should realise that quite often experts are needed to

confirm identification (and hence the importance of

museums, botanic gardens and herbaria, and expert

taxonomists).

Differentiation

For less able students:• Studentsmakeupadouble-namesystemtodescribe

a range of science equipment, e.g. Cylindricus

measurus (measuring cylinder). See which groups

can make up names that distinguish different types

of equipment, such as different sizes of beakers or

measuring cylinders.

For more able students:• StudentsinvestigatemoreLatinorGreekwordsthat

have been used in naming species and genera.

• Exploreexamplesofsubspeciesandplanthybrids

(other than those bred for agriculture).

individual name (not one of their own given

names). The aim is to make up a name that is

memorable. Students walk around the room

introducing themselves to students from other

groups. Students return to their regular seats

and record as many names of students as they

can remember. Discuss which names were

more memorable. What are the advantages of

a double name?

Additional informationAs more sophisticated biochemical tools

are now used to compare species, new

relationships are being discovered. One

concept that results from this is the

delineation of subspecies. Subspecies and

hybrids resulting from interbreeding between

species are common in plants.

Common misconceptionsWe often use very simplified examples of

dichotomous keys with the types of yes/no

questions that are asked. To identify species,

highly technical language and detailed

observations are often necessary. While it

is good to understand the process, students

TEACHER OBOOK EXTRASClassifying Life interactive www.pbs.org/wgbh/nova/nature/classifying-life.htmlDescription of classification systems www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDivers_class.html

WORKBOOK OBOOK EXTRAS > Risk assessment: Activity 2.2.1 Grouping

animals > Editable risk assessment of the activity written


RESOURCES



lionfish bream

tigershark

whaleshark

largestriped

finssmallfins eats

people doesn’t eatpeoplebonyfish cartilaginous

fish

jawless fish

hydra

sea fan

coral

fish

cnidarian jellyfish

medusabox

jellyfish

seaanenomepolyp

octopusvenomous blue–ringed

octopus

notvenomous

common octopus

salamanderfrog

not commonlyfound in Australia

commonlyfound in Australia

can live on bothland and water

lives in water only

lives

on lan

d only

tiger

spider

elephant

smallearsbig

ears

Indianelephant

Africanelephant

funnel–

web

spider

lethalnon

lethal

black

house

spider

tarantula

hairybody

blackbody

flowerspider mainly

greenmulti–

colouredmainlyblack

redbackspider

sabre–toothed tigerextinct

not extinct

Indian tiger

ANIMALS

Understanding scientific namesThe scientific names of most living things usually come from Latin (and sometimes Greek) words. Why use Latin? The language of science for many centuries was Latin. This enabled scientists who lived in different countries and spoke different languages to use a common language to communicate their work and discoveries.

The words used describe physical features, behaviours and even colours of organisms. Some basic understanding of Greek and Latin will help you to interpret scientific names. Table 2.4 contains some examples.

Table 2.4 Some scientific words and their meanings.

latin/greek root word English meaning

Aculeat Spiny

Ornitho Bird

Arctus Bear

Phascol Pouch

Anatinus Duck-like

Pus Foot

Cinereus Grey

Rufus Red

Gloss Tongue

Tachy Fast

Rhynchus Snout

Chlamy Caped

Macro Large

Saurus Lizard

Remember1 Identify who invented the naming system that is still used today to name living

things.2 Identify the first level of the Linnaean classification system under ‘All living things’.3 Mnemonics are often used to help you remember things. Create your own to

remember the seven levels of classification.4 Define the term ‘species’.

apply5 Apply the information in Table 2.4 to match the scientific

names of these Australian animals with their pictures in Figure 2.29.a Macropus rufusb Tachyglossus aculeatusc Phascolarctus cinereusd Ornithorhynchus anatinuse Chlamydosaurus kingie

6 What do you think a Macroglossus aculeatus might look like? Sketch this imaginary animal, using Table 2.4 to help.

7 Explain why giving your address as ‘John Campbell, Southern Hemisphere, The Earth’ would not be a good way to get many letters.

8 With the same idea from question 7, explain why taxonomists need a very detailed system like the Linnaean classification system to group living things.

9 Research the scientific names for three different animals. For each:a Work out their full classificationb Describe their appearancec Determine what their scientific name means (some are more obvious than others)

and whether this suits.

QUESTIONS 2.2.1: THE LINNAEAN CLASSIFICATION SYSTEM

USING KEYS FOR IDENTIFICATIONWhen you visit an outdoor market, you may wander around for some time before you find what you want. An online store is more organised, with similar items grouped together in a menu. If you were looking for the latest movie to buy, you would first locate the entertainment section. In that section you will often find all the games, music and movies together. There might be several submenus of movies and the one you want might be in a section for latest releases. Scientists use classification systems to group objects or organisms together based on similar characteristics. Classification makes the names and descriptions of organisms easier to find.

Circular keysCircular keys can also be used to separate and classify different things. With a circular key, you start off in the centre of the circle and follow the path that correctly identifies the features that you can see. Rather than the branches seen in dichotomous keys, circular keys contain everything within the circle. Each level of a circular key determines the next step that you will follow.

Figure 2.30 A circular key is another tool for classification.

1

2

3

4

5

Figure 2.29


SYLLABUS LINKS






Learning across the curriculum • Critical and creative thinking• Literacy

Start activity: Using keys for identificationIt is important to distinguish the difference between

classification (grouping of organisms) and identification

(determining an unknown organism). Newly discovered

organisms are classified, while unknown organisms

are identified. No one person would be able to identify

every known species on the planet, particularly as many

species are extremely similar. Keys are tools that explain

the classification process and can be followed until the

unknown organism is identified. Effective keys must be

very specific, very clear and easy to follow in order to get

a correct identification.

Activity: Identification activityStudents work in groups. They are given five unfamiliar

pieces of laboratory equipment labelled A, B, C, D

and E with a table of the names of the equipment

beside a description of each. Students have to match

the letter of the piece of equipment to a name using

their observations and the descriptions. Discuss how

difficult this process would be if you were doing a

field study and needed to identify numerous species of

plants and animals in the field. Then give the students

a dichotomous key for the equipment and explain how

to use it. Discuss the benefits of an organised system for

identification.

Teaching strategiesGiving students opportunities for practical experiences

best develops skills in using and designing keys. There

are many printable keys available on the Internet for

students to practice with. Ask students to regularly

provide a real-life example where they have

classified items, and get them to provide

suitable characteristics to use to classify items

they are already familiar with.

Differentiation

For less able students:• Provideprintedcopiesofcircularkeys

and ask students to draw the path they

followed to identify an object.

For more able students:• Provideanumberofitems,orimagesof

items, and ask students to design their

own circular key.

Extension activityGive students a list of common names of

plants, for example ‘bottle brush’. Students

research the plant and discover the confusion

that arises from the use of common names.

Student groups could compete to see how

many scientific names they could find for

the one single common name, for example



lionfish bream

tigershark

whaleshark

largestriped

finssmallfins eats

people doesn’t eatpeoplebonyfish cartilaginous

fish

jawless fish

hydra

sea fan

coral

fish

cnidarian jellyfish

medusabox

jellyfish

seaanenomepolyp

octopusvenomous blue–ringed

octopus

notvenomous

common octopus

salamanderfrog

not commonlyfound in Australia

commonlyfound in Australia

can live on bothland and water

lives in water only

lives

on lan

d only

tiger

spider

elephant

smallearsbig

ears

Indianelephant

Africanelephant

funnel–

web

spider

lethalnon

lethal

black

house

spider

tarantula

hairybody

blackbody

flowerspider mainly

greenmulti–

colouredmainlyblack

redbackspider

sabre–toothed tigerextinct

not extinct

Indian tiger

ANIMALS

Understanding scientific namesThe scientific names of most living things usually come from Latin (and sometimes Greek) words. Why use Latin? The language of science for many centuries was Latin. This enabled scientists who lived in different countries and spoke different languages to use a common language to communicate their work and discoveries.

The words used describe physical features, behaviours and even colours of organisms. Some basic understanding of Greek and Latin will help you to interpret scientific names. Table 2.4 contains some examples.

Table 2.4 Some scientific words and their meanings.

latin/greek root word English meaning

Aculeat Spiny

Ornitho Bird

Arctus Bear

Phascol Pouch

Anatinus Duck-like

Pus Foot

Cinereus Grey

Rufus Red

Gloss Tongue

Tachy Fast

Rhynchus Snout

Chlamy Caped

Macro Large

Saurus Lizard

Remember1 Identify who invented the naming system that is still used today to name living

things.2 Identify the first level of the Linnaean classification system under ‘All living things’.3 Mnemonics are often used to help you remember things. Create your own to

remember the seven levels of classification.4 Define the term ‘species’.

apply5 Apply the information in Table 2.4 to match the scientific

names of these Australian animals with their pictures in Figure 2.29.a Macropus rufusb Tachyglossus aculeatusc Phascolarctus cinereusd Ornithorhynchus anatinuse Chlamydosaurus kingie

6 What do you think a Macroglossus aculeatus might look like? Sketch this imaginary animal, using Table 2.4 to help.

7 Explain why giving your address as ‘John Campbell, Southern Hemisphere, The Earth’ would not be a good way to get many letters.

8 With the same idea from question 7, explain why taxonomists need a very detailed system like the Linnaean classification system to group living things.

9 Research the scientific names for three different animals. For each:a Work out their full classificationb Describe their appearancec Determine what their scientific name means (some are more obvious than others)

and whether this suits.

QUESTIONS 2.2.1: THE LINNAEAN CLASSIFICATION SYSTEM

USING KEYS FOR IDENTIFICATIONWhen you visit an outdoor market, you may wander around for some time before you find what you want. An online store is more organised, with similar items grouped together in a menu. If you were looking for the latest movie to buy, you would first locate the entertainment section. In that section you will often find all the games, music and movies together. There might be several submenus of movies and the one you want might be in a section for latest releases. Scientists use classification systems to group objects or organisms together based on similar characteristics. Classification makes the names and descriptions of organisms easier to find.

Circular keysCircular keys can also be used to separate and classify different things. With a circular key, you start off in the centre of the circle and follow the path that correctly identifies the features that you can see. Rather than the branches seen in dichotomous keys, circular keys contain everything within the circle. Each level of a circular key determines the next step that you will follow.

Figure 2.30 A circular key is another tool for classification.

1

2

3

4

5

Figure 2.29


6 Student responses will vary, but a Macroglossus aculeatus would, by name, be a large-tongued spiny creature.

7 Giving your address as ‘John Campbell, Southern Hemisphere, The Earth’ is too general. It doesn’t provide enough information for someone to locate you to deliver the letters.

8 Taxonomists need very detailed systems so they can make sense of all the organisms studied and identify a specific species in a simple and practical manner. Every species can be given a unique name (as opposed to common names, which are often neither consistent nor unique).

9 Answers will vary depending on animals chosen.

‘gum tree’. Discuss the advantages and

disadvantages of the use of common names

for plants and animals. What would happen

if children had to remember Canis familiaris

instead of dog?

ANSWERS

QUESTIONS 2.2.1 The Linnaean classification system1 Carolus Linnaeus invented the naming

system that is still used today to name living things.

2 The first level of the Linnaean classification system is ‘kingdom’.

3 Student responses will very but must list the order of the classification levels as: kingdom, phylum, class, order, family, genus, species.

4 ‘Species’ means a group of organisms that look similar to each other and can successfully breed together.

5 a Macropus rufus: red kangaroo (5)

b Tachyglossus aculeatus: short-beaked echidna (4)

c Phascolarctus cinereus: koala (1)d Ornithorhynchus anatinus: platypus (2)e Chlamydosaurus kingii: frill-necked

lizard (3)

TEACHER OBOOK EXTRAS > Online interactive keys, such as the freshwater

lake investigation Macrobiotica, are fun and give students instant feedback. There is also one on plants.

> lrrpublic.cli.det.nsw.edu.au/lrrSecure/Sites/Web/macrobiotica_v2/index.htm

> webworldwonders.firn.edu/cameras/keys/sa/tree.html

WORKBOOK OBOOK EXTRAS > Workbook 2.2: Classification using seven levels > Editable version of workbook activity, which can

be digitally assigned to students for homework

RESOURCES



ACTIVITY 2.2.3: MAKING A TABULAR DICHOTOMOUS KEY

Scientists often use tabular dichotomous keys to determine the group to which an animal or plant belongs.

1 Use the following tabular key to identify the class of each of the animals shown.

1Feathers present Birds

No feathers present Go to 2

2Hair or fur present Mammals

No hair or fur Go to 3

3Fins present Fish

No fins present Go to 4

4Has moist skin, no scales Amphibians

Has scales Reptiles

2 Use the information given about Dr Redback’s family in Activity 2.2.2 to create your own tabular dichotomous key.

Dichotomous keysChallengeUsing what you have discovered about the characteristics of living things, design your own dichotomous key.

Questioning and predictingThink about objects that could be sorted into two groups. For example, you might like to use snack foods such as corn chips, flavoured chips or plain chips.

PlanningWhat similarities or differences can you find to separate the objects into two groups?

ConductingWhat other similarities or differences can you find to separate the objects further? Keep dividing into two groups until each item is on its own.

Processing, analysing and evaluating

1 Draw a dichotomous key to show how you grouped the objects.2 How hard was it to divide your objects into different groups? Could you have used

a better group of objects?

Communicating

1 Swap your dichotomous key with another group.2 How effectively have they constructed a dichotomous key? Ask them to evaluate

your key.3 Which was the best dichotomous key designed in your class?4 What features made it the best key?5 Groups may have come up with different keys to separate the same objects.

Explain how this might have occurred.

STUDENT DESIGN TASK

Dichotomous keysA key is a visual tool used in the identification of organisms. A key is often more useful than a list of characteristics and similarities of each group. One common type of key is called the dichotomous key (pronounced dye-COT-o-muss), named because the branches always split into two (di means two). Scientists use this type of key to make simple ‘yes’ or ‘no’ decisions. For example, does the animal have fur (yes/no)? Does it have scales (yes/no)? Each answer leads to another branch and another question. This key only works if someone else has already classified the animal. A newly discovered organism would

need to be studied first and then new branches added to the key if appropriate branches do not already exist.

Dichotomous keys can be presented in various ways. A branched key (like a tree) helps us to see how a particular member of a group fits in with all the rest. The yes/no decision is made at the junction of the branches, and the endpoint is the name of the organism. Tabular keys contain the same information as branched keys but they are set out in a table or numbered list where you read through the numbered options in order. Each item presents two options, and more information is given at each step. Eventually the organism can be identified.

ACTIVITY 2.2.2: DR REDBACK’S FAMILY

Dr Redback loves to send out Christmas cards with the family photo on the front. One year, just for fun, he included a dichotomous key to help everyone identify all his family and pets. Use the picture of Dr Redback’s family and the dichotomous key provided to work out who is who.

Figure 2.31 Dr Redback’s family.

Hair all over body

No feathers covering body

Feathers covering body

Male

Bugs

Moggie

Buddy

Scott

Peter

Richard

Vanessa

Stephanie

Long ears

Long tail

Short tail

No facial hair

Facial hair

Red hair

Not red hairFemale

Unable to walk

Able to walk

Short ears

Hair covering parts of body

REDBACK FAMILY

CharlieFlying animals

Figure 2.32 Dichotomous key for Dr Redback’s family.

a

b

c

d

e


SYLLABUS LINKS

Outcomes SC4-14LW relates the structure and function of living things to their classification, survival and reproduction

Knowledge and understanding LW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).Students:b classify a variety of living things based on





Activity 2.2.2: Dr Redback’s familySC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-8WS Problem solving

Activity 2.2.3: Making a tabular dichotomous keySC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and information

Student design task: Dichotomous keysSC4-4WS Questioning and predictingSC4-5WS Planning investigationsSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-8WS Problem solvingSC4-9WS Communicating


Teaching strategyIt is often easiest to create a dichotomous key as

you classify the group of objects. So each time the

group is separated, a new branch is added to the

dichotomous key.

Differentiation

For less able students:• Thesestudentswillneedmanyopportunities

to use dichotomous keys. Ensure the

keys they use have clear diagrams and

explanations of any terminology. Keys

developed to identify a range of non-living

items should help them practise the skills.

For more able students:• Directstudentstoexploretheonline

resource ‘What is the key to classification?’.

Activity: Assessment taskUsing dichotomous keys is an important skill

that is easily incorporated into an assessment

task. It is an obvious component of written

class tests, and can be used in practical tests

where students rotate around stations set

up in the laboratory and answer a number

of questions. Questions can be set across a

wide range of abilities. Some questions may

present students with a diagram, e.g. showing

the difference between compound and simple

leaves, asking them to identify a compound

leaf from a set of labelled specimens. Some










3Fins present Fish



Has scales Reptiles









Communicating




STUDENT DESIGN TASK







Hair all over body



Male

Bugs

Moggie

Buddy

Scott

Peter

Richard

Vanessa

Stephanie

Long ears

Long tail

Short tail

No facial hair

Facial hair

Red hair

Not red hairFemale

Unable to walk

Able to walk

Short ears


REDBACK FAMILY



a

b

c

d

e


ACTIVITY 2.2.3 Making a tabular dichotomous key1 The animals in the images, clockwise from top left,

fit the following classes: Birds, Mammals, Fish, Amphibians, Reptiles.

2 A possible tabular dichotomous key for Dr Redback’s family is can be seen on page 104 of the appendix.

STUDENT DESIGN TASK Dichotomous keysThis activity could be modelled to the students by first constructing a dichotomous key, as a class, using the eight characteristics of living things. The key will have three possible outcomes: living, dead and non-living. Test the key out on a range of living, non-living and dead things such as the bushfire example.

Before starting this activity, have students come up with their own peer-assessment criteria. They can then use this to assess each other’s dichotomous keys. The ‘best’ key, as per class consensus, should be put up on display with annotations describing its strengths.

questions may involve only one or two steps

in a dichotomous key while others could be

quite complex. Dichotomous keys can be

used in several stages of assessment, not just

assessment of learning.

ANSWERS

ACTIVITY 2.2.2 Dr Redback’s family• Bugs – rabbit; Moggie – cat; Buddy –

dog; Scott – baby son; Peter – elder son; Richard – Dr Redback; Vanessa – his wife; Stephanie – his daughter; Charlie – bird

Students might benefit from using their fingers to trace the path they take on the key.

Students could be challenged to work backwards from the name of the family member to identify the correct person or animal in the illustration.

Students could be asked to write down the characteristics of each person or animal. These characteristics could be assessed to decide whether they were the most appropriate feature to use for grouping, and whether the feature would be appropriate in a larger group of people and animals.

STUDENT OBOOK EXTRAS > What is the Key to Classification? www.mdsg.

umd.edu/programs/education/interactive_lessons/key

Interactive: Using a dichotomous key

> Interactive task where students use drop-down menus and drag-and-drop items to complete a dichotomous key.

TEACHER OBOOK EXTRAS > Risk assessment: Activity 2.2.2 Dr Redback’s

family > Editable risk assessment of the activity written


> Risk assessment: Activity 2.2.3 Making a tabular dichotomous key


> Workbook 2.3: Using keys > Editable version of workbook activity, which can

be digitally assigned to students for homework > Risk assessment: Student Design Task

Dichotomous keys > Editable risk assessment of the activity written


RESOURCES



2.2CHECKPOINT

Remember1 Recall the definition of a dichotomous key.2 Explain what ‘dichotomous’ refers to.3 Suggest a reason why dichotomous keys may be presented as a table.

apply4 Which of the following descriptions would be good to use to identify a group of

birds in a dichotomous key? Justify why each one is or is not a good method of classification:a is eating bird seedb has a blue stripe above the eyec has a wingspan of 32 cmd has a broken lege is sitting on the groundf has a high-pitched, bell-like songg has brown tail feathers

5 Draw a circular key that could be used to identify laboratory equipment. Include these items: tripod stand, Bunsen burner, gauze mat, 50 mL beaker, 150 mL beaker, 100 mL measuring cylinder, 10 mL measuring cylinder, 500 mL beaker, 500 mL measuring cylinder, retort stand, clamp.

6 Design a dichotomous key to identify dinosaurs. You should research at least ten dinosaurs of the Jurassic period (find out when this was), find drawings of them and identify characteristics that could be used to classify them. Construct a table of their common characteristics and look for common ones you could use to build a dichotomous key for identifying them. Include the names and pictures of the dinosaurs on the key.

7 Use the dichotomous key in Figure 2.34 to help with the following tasks:a Identify and name

the four beetles in Figure 2.33.

b Draw a simple sketch of the following:i frope beetleii gring beetleiii gripe beetleiv frong beetle

Figure 2.33

Figure 2.35

QUESTIONS 2.2.2: USING KEYS FOR IDENTIFICATION

ALL BEETLES

Round

Oval

Stripes

Spots

Stripes

Spots

Stripes

Spots

Stripes

Spots

Antennae

No antennae

Antennae

No antennae

Wings

No wings

Wings

No wings

Wings

No wings

Wings

No wings

Wings

Wings

No wings

No wings

Wings

Wings

No wings

No wings

Fring

Frong

Frap

Frip

Fripe

Frope

Frot

Frit

Gring

Gripe

Grong

Grope

Grip

Grot

Grop

Grit

USING KEYS AS TOOLS FOR CLASSIFICATIONRemember and understand1 You have a family name and a given

name. Compare the way people are named with Linnaeus’s double-name system. [1 mark]

2 Explain why most keys are dichotomous. [1 mark]

3 Identify why classification is important. [1 mark]

4 Explain why some features are not appropriate to use as features to use in a dichotomous key. Use at least two examples in your answer. [2 marks]

5 Explain why scientific names are often in Latin or Greek. [1 mark]

6 Outline the advantages of using a dichotomous key. [1 mark]

apply7 Arrange these terms in order from the

level that contains the most number of organisms to the level that contains the least number of organisms: family, kingdom, species, class, phylum, genus, order. [1 mark]

8 Refer back to Activity 2.2.2 about Dr Redback’s family. Demonstrate how you might adjust the dichotomous key if: his ‘family’ included his sister, Melinda, and mother, Frances; he had two daughters, Stef and Gemma (Stef wears glasses); and he had a pet lizard named Stealth and not a bird named Charlie. [3 marks]

9 Empty your school bag or pencil case and design a dichotomous key of its contents. [3 marks]

analyse and evaluate10 Identify some of the difficulties of using

your dichotomous key on the contents of someone else’s bag or pencil case. [1 mark]

11 Download a copy of the collection of insects in Figure 2.35 from your obook, or photocopy and enlarge the figure from your book.

a Cut out the pictures of the insects so you can move them around on your desk.

b Working on your own, sort the insects into groups based on some aspect of their appearance. Justify your system of classification. [1 mark]

c Compare your groupings with those of a partner. Between the two of you, can you think of other ways to classify the insects? [1 mark]

d With your partner, construct a dichotomous key for this group of insects. [3 marks]

12 Discuss the limitations of a dichotomous key. [2 marks]

13 Discuss why the invention of the dichotomous key was important to the development of the classification system. [1 mark]

Critical and creative thinking14 Propose a new system of classification

for organising life on the Earth. Which kingdom would you be in? [2 marks]

TOTal MaRKS [ /25]Figure 2.34

1

2

3

4


ANSWERS

QUESTIONS 2.2.2 Using keys for identification1 A dichotomous key is a visual tool used in the

classification of organisms. Scientists use this type of key to make simple ‘yes’ or ‘no’ decisions at each branch. Each answer leads to another branch and another question, and eventually leads to the identity of the organism. The successful use of a dichotomous key depends on making accurate observations of the organism.

2 It is called a ‘dichotomous’ key because the branches always split into two.

3 Large dichotomous keys that are used to identify a large number of items can take up a lot of space on the page. Presenting them as tables with instructions to go to different rows saves space, making them easier to manage and use.

4 Classifying groups of birds:

a is eating bird seed: not good, because it doesn’t describe a characteristic; it describes a behaviour that many birds will display

b has a blue stripe above the eye: good, because it describes something the bird can be identified by

c has a wing span of 32 cm: good, but would need to be accompanied with other information (juvenile/adult, colour, etc.)

d has a broken leg: not good, because it describes something that is not permanent

e is sitting on the ground: not good, because it is a behaviour that is not permanent

f has a high-pitched, bell-like song: good, because not all birds have the same song

g has brown tail feathers: good, because it describes characteristics the bird has

5 Student responses will vary. Students are likely to group the equipment by size first, however, they could also start by grouping according to whether the equipment is used for measurement or for another purpose.

6 Student responses will vary depending on the dinosaurs researched, but must show logical divisions at each step.

7 a i grot

ii frapiii grongiv frot

b Students’ drawings should have the following elements:i frope: round, no antennae, stripes, no wingsii gring: oval, antennae, stripes, wingsiii gripe: oval, no antennae, stripes, wingsiv frong: round, antennae, stripes, no wings

CHECKPOINT 2.2 Using keys as tools for classification 1 They are similar in that they both use a double-name

system. Given names are used frequently, and in

Australia they are generally recorded first, followed by our family name. Linnaeus’s system starts with the genus name (equivalent to the family name) and ends with the equivalent of the given name. Linnaeus’s system names all members of a species with a unique name, whereas the common way of naming humans gives individual a unique name.

There are substantial differences as well. Many family names are quite common (e.g. ‘Smith’) and many people may have the same family name but are not directly related. People also can change their

family name (e.g. through marriage), or have combined family names. Sisters who have changed their family names through marriage no longer have the relationship association indicated in their names. The double-name system identifies an individual, whereas Linnaeus’s binomial system identifies a unique group or species.

2 Most keys are dichotomous so scientists can make simple ‘yes’ or ‘no’ decisions at each branch.

3 Classification is important to understand the structure, function and behaviour



2.2CHECKPOINT

Remember1 Recall the definition of a dichotomous key.2 Explain what ‘dichotomous’ refers to.3 Suggest a reason why dichotomous keys may be presented as a table.

apply4 Which of the following descriptions would be good to use to identify a group of

birds in a dichotomous key? Justify why each one is or is not a good method of classification:a is eating bird seedb has a blue stripe above the eyec has a wingspan of 32 cmd has a broken lege is sitting on the groundf has a high-pitched, bell-like songg has brown tail feathers

5 Draw a circular key that could be used to identify laboratory equipment. Include these items: tripod stand, Bunsen burner, gauze mat, 50 mL beaker, 150 mL beaker, 100 mL measuring cylinder, 10 mL measuring cylinder, 500 mL beaker, 500 mL measuring cylinder, retort stand, clamp.

6 Design a dichotomous key to identify dinosaurs. You should research at least ten dinosaurs of the Jurassic period (find out when this was), find drawings of them and identify characteristics that could be used to classify them. Construct a table of their common characteristics and look for common ones you could use to build a dichotomous key for identifying them. Include the names and pictures of the dinosaurs on the key.

7 Use the dichotomous key in Figure 2.34 to help with the following tasks:a Identify and name

the four beetles in Figure 2.33.

b Draw a simple sketch of the following:i frope beetleii gring beetleiii gripe beetleiv frong beetle

Figure 2.33

Figure 2.35

QUESTIONS 2.2.2: USING KEYS FOR IDENTIFICATION

ALL BEETLES

Round

Oval

Stripes

Spots

Stripes

Spots

Stripes

Spots

Stripes

Spots

Antennae

No antennae

Antennae

No antennae

Wings

No wings

Wings

No wings

Wings

No wings

Wings

No wings

Wings

Wings

No wings

No wings

Wings

Wings

No wings

No wings

Fring

Frong

Frap

Frip

Fripe

Frope

Frot

Frit

Gring

Gripe

Grong

Grope

Grip

Grot

Grop

Grit

USING KEYS AS TOOLS FOR CLASSIFICATIONRemember and understand1 You have a family name and a given

name. Compare the way people are named with Linnaeus’s double-name system. [1 mark]

2 Explain why most keys are dichotomous. [1 mark]

3 Identify why classification is important. [1 mark]

4 Explain why some features are not appropriate to use as features to use in a dichotomous key. Use at least two examples in your answer. [2 marks]

5 Explain why scientific names are often in Latin or Greek. [1 mark]

6 Outline the advantages of using a dichotomous key. [1 mark]

apply7 Arrange these terms in order from the

level that contains the most number of organisms to the level that contains the least number of organisms: family, kingdom, species, class, phylum, genus, order. [1 mark]

8 Refer back to Activity 2.2.2 about Dr Redback’s family. Demonstrate how you might adjust the dichotomous key if: his ‘family’ included his sister, Melinda, and mother, Frances; he had two daughters, Stef and Gemma (Stef wears glasses); and he had a pet lizard named Stealth and not a bird named Charlie. [3 marks]

9 Empty your school bag or pencil case and design a dichotomous key of its contents. [3 marks]

analyse and evaluate10 Identify some of the difficulties of using

your dichotomous key on the contents of someone else’s bag or pencil case. [1 mark]

11 Download a copy of the collection of insects in Figure 2.35 from your obook, or photocopy and enlarge the figure from your book.

a Cut out the pictures of the insects so you can move them around on your desk.

b Working on your own, sort the insects into groups based on some aspect of their appearance. Justify your system of classification. [1 mark]

c Compare your groupings with those of a partner. Between the two of you, can you think of other ways to classify the insects? [1 mark]

d With your partner, construct a dichotomous key for this group of insects. [3 marks]

12 Discuss the limitations of a dichotomous key. [2 marks]

13 Discuss why the invention of the dichotomous key was important to the development of the classification system. [1 mark]

Critical and creative thinking14 Propose a new system of classification

for organising life on the Earth. Which kingdom would you be in? [2 marks]

TOTal MaRKS [ /25]Figure 2.34

1

2

3

4


• changethe‘featherscoveringbody’to‘scalescovering body’ to include the pet lizard

• add‘immediatefamilymembers’and‘otherfamilymembers’ to include his sister and mother

• addanotherbranchforfemalesunder20toseparate the daughters

• removethe‘able/unabletowalk’branchesasallfamily members are able to walk.

9 Student responses will vary, but must show logical divisions at each branch. For example, they may start with ‘1a writing or drawing instrument’, ‘1b not a writing or drawing instrument’. Other differences could be the colour of pens, the materials they are made out of, or whether they use ink or graphite.

10 Student responses will vary. Someone else’s pencil case may have different items not included in the key devised. For example, they may contain geometrical instruments that are not described or that are classified into the same group, rather than being distinguished.

11 Classifying insects

b/c Student responses will vary but should include groups based on the number of wing pairs, the length of antennas or body shape.

d Student responses will vary, but must show logical divisions at each branch.

12 Some limitations of a dichotomous key:

• Onlyspeciesalreadydiscoveredandnamedbysomeone else can be identified.

• Assumptionsaresometimesinvolvedwhenmaking the yes/no decision.

• Theorganismbeingobservedmustbeincludedinthe dichotomous key.

13 The dichotomous key was important to the development of the classification system as it provided scientists with a simple way to identify and group species based on what they observed.

Critical and creative thinking14 Student responses will vary, but must include logical

groupings of organisms based on appropriate characteristics.

of different organisms. Organisms that are classified together will have similar characteristics. Classification enables scientists to communicate easily about different organisms and share information.

4 Characteristics not appropriate to use in a dichotomous key are those that are not consistent across all organisms of that species, or that may change over time. Inconsistent characteristics might include food eaten, height of organisms, or colour of fur or scales. Changeable characteristics might include mass of the organism or number of legs (some animals metemorphise, such as some amphibians and insects).

5 Scientific names were originally in Latin or Greek because they were common languages spoken across the world. Even though Latin is no longer commonly spoken, tradition dictates that Latin and Greek are still used for scientific names today.

6 Advantages of using a dichotomous key are that it requires simple ‘yes’ or ‘no’ decisions, each answer leads to another branch and another question, and it is often simple to follow and understand.

7 kingdom, phylum, class, order, family, genus, species

8 Students may opt to:



> Printable: Classifying insects > Printable copy of Figure 2.35 for students to cut

out when completing Q11 > Checkpoint Worksheet: Support 2.2 > Digitally assignable worksheet designed to

support struggling students to help bring them up to the expected level

> Checkpoint Worksheet: Consolidate 2.2 > Digitally assignable worksheet designed to

consolidate student understanding > Checkpoint Worksheet: Extend 2.2

RESOURCES



PlantaePlants include trees, vines, bushes, ferns, mosses, weeds and grasses. They are autotrophs, that is, they make their own food from sunlight. Plants are multicellular and their cells contain DNA in a nucleus, but their cells have a cell wall around the outside of the cell. Scientists who study plants are called botanists.

FungiFungi include mushrooms, toadstools, yeasts, puffballs, moulds and truffles. Some fungi grow in wood and in soil, and develop from tiny spores. Fungi do not make their own food. Instead they feed on the remains of dead animals and plants. Some fungi can cause diseases, such as tinea (athlete’s foot). Scientists who study fungi are called mycologists.

Fungi and the following two kingdoms consist of many organisms that are unicellular (only have one cell). They are usually so small they cannot be seen without a microscope and as such are also called microorganisms. There are three main types of fungi: mushrooms, yeasts and moulds. The types of fungi are classified based on the way in which they reproduce.

The visible part of most fungi, mushrooms in particular, is really just the part that produces spores for reproduction. Much of the fungus is not visible to the naked eye but consists of very fine hair-like projections that spread throughout the soil or host organism. Some fungi, monerans and protists also become visible to the naked eye when they grow in large colonies, which are made up of large groups of individual, self-sufficient cells living together.

KINGDOMS

2.3 CLASSIFICATION TODAY

The earliest taxonomists (scientists who classify living things) divided all living things into two groups: plants and animals. As new technology such as microscopes developed, very small organisms were discovered that did not fit into either of these groups. Scientists began to question the classification of other organisms such as mushrooms: did they really belong to the plant group? After all, they looked different under the microscope and they didn’t produce their own food.

These days, scientists generally agree on classifying living things into five large kingdoms based on:

• the features of their cells (small structures that make up the organism)

• how they obtain nutrients

• their general appearance.

AnimaliaAll organisms in this kingdom are multicellular, that is, they are made up of many cells. Each cell stores its genetic material (DNA) in a small internal structure called the nucleus. Animal cells do not have a cell wall. Animals gain energy from other living things. We belong in this kingdom. Scientists who study animals are generally called zoologists.

The animal kingdom contains a large range of organisms: from the tiniest fairy fly, where 50 could fit within 1 millimetre, to the giant blue whale, which is up to 33 metres long—about the size of a house. Size is not a very suitable characteristic for classifying animals, especially because most grow over time. So what characteristics are chosen to group animals? And where do humans fit in this system?

b

c

e

Figure 2.36 Animal kingdom: (a) The proboscis monkey (Nasalis larvatus) has the biggest nose. (b) Port Jackson shark. (c) Pangolin. (d) Damselfly. (e) Goanna.

a

d

b

e

c

a

d

Figure 2.37 Plant kingdom: (a) Flowering gum. (b) Moss. (c) The smelliest plant, the Rafflesia, is found in South-East Asia. Its flower can measure up to 90 centimetres across and weigh about 11 kilograms. To attract insects when it blooms it gives off a rotten meat odour. (d) Cactus. (e) Wheat.

a b c

Figure 2.38 Fungi kingdom: (a) The hair-like filaments of the yeast Candida albicans as seen under a microscope. (b) Mould. (c) Mushrooms.

7574 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4 2.3 ClaSSIFICaTIOn TODay




Students:d identify some examples of groups of

microorganisms





INTRODUCING UNIT 2.3

This section provides students with an outline of the currently accepted major classification groups of animals and plants. Some students will be familiar with the classification of vertebrate animals, but may find the classification of microorganism and plants new and challenging. The ideas introduced in ‘The changing face of classification’ may also be challenging for some students.

Starter activity: KingdomsGroup students and provide each group with the images

of the representatives of each kingdom as seen in

Figures 2.36, 2.37, 2.38, 2.39 and 2.40. These can be

obtained from the obook. Each group tries to classify

the organisms based on the observable characteristics.

Students will likely group the microorganisms together,

keeping plants and animals separate. Encourage students

to classify further, so that they have at least three

levels of classification based on the images. Each group

should then construct a dichotomous key based on their

classification.

While this task may model the way

taxonomists work, good classification

depends on an in-depth understanding of the

characteristics of the species or organisms

involved. Modern scientists are adding new

criteria, such as the structures of genetic

material and other biochemical, to add to the

understanding of relationships.

Teaching strategyProvide students with a number of animal

illustrations or photographs. For each

image, they record how they knew the

organism illustrated was an animal. Students

generate their own list of the characteristics

of animals. Then, for each characteristic,

students identify an example of an animal

with the characteristic and one without the

characteristic.

Most students will be more familiar

with animals than plants, and even less

familiar with fungi, protists and monerans.

For each kingdom, recognise student prior

understanding and then work to give them

experiences of the new knowledge. Students

could construct a KWL (Know – what they



PlantaePlants include trees, vines, bushes, ferns, mosses, weeds and grasses. They are autotrophs, that is, they make their own food from sunlight. Plants are multicellular and their cells contain DNA in a nucleus, but their cells have a cell wall around the outside of the cell. Scientists who study plants are called botanists.

FungiFungi include mushrooms, toadstools, yeasts, puffballs, moulds and truffles. Some fungi grow in wood and in soil, and develop from tiny spores. Fungi do not make their own food. Instead they feed on the remains of dead animals and plants. Some fungi can cause diseases, such as tinea (athlete’s foot). Scientists who study fungi are called mycologists.

Fungi and the following two kingdoms consist of many organisms that are unicellular (only have one cell). They are usually so small they cannot be seen without a microscope and as such are also called microorganisms. There are three main types of fungi: mushrooms, yeasts and moulds. The types of fungi are classified based on the way in which they reproduce.

The visible part of most fungi, mushrooms in particular, is really just the part that produces spores for reproduction. Much of the fungus is not visible to the naked eye but consists of very fine hair-like projections that spread throughout the soil or host organism. Some fungi, monerans and protists also become visible to the naked eye when they grow in large colonies, which are made up of large groups of individual, self-sufficient cells living together.

KINGDOMS

2.3 CLASSIFICATION TODAY

The earliest taxonomists (scientists who classify living things) divided all living things into two groups: plants and animals. As new technology such as microscopes developed, very small organisms were discovered that did not fit into either of these groups. Scientists began to question the classification of other organisms such as mushrooms: did they really belong to the plant group? After all, they looked different under the microscope and they didn’t produce their own food.

These days, scientists generally agree on classifying living things into five large kingdoms based on:

• the features of their cells (small structures that make up the organism)

• how they obtain nutrients

• their general appearance.

AnimaliaAll organisms in this kingdom are multicellular, that is, they are made up of many cells. Each cell stores its genetic material (DNA) in a small internal structure called the nucleus. Animal cells do not have a cell wall. Animals gain energy from other living things. We belong in this kingdom. Scientists who study animals are generally called zoologists.

The animal kingdom contains a large range of organisms: from the tiniest fairy fly, where 50 could fit within 1 millimetre, to the giant blue whale, which is up to 33 metres long—about the size of a house. Size is not a very suitable characteristic for classifying animals, especially because most grow over time. So what characteristics are chosen to group animals? And where do humans fit in this system?

b

c

e

Figure 2.36 Animal kingdom: (a) The proboscis monkey (Nasalis larvatus) has the biggest nose. (b) Port Jackson shark. (c) Pangolin. (d) Damselfly. (e) Goanna.

a

d

b

e

c

a

d

Figure 2.37 Plant kingdom: (a) Flowering gum. (b) Moss. (c) The smelliest plant, the Rafflesia, is found in South-East Asia. Its flower can measure up to 90 centimetres across and weigh about 11 kilograms. To attract insects when it blooms it gives off a rotten meat odour. (d) Cactus. (e) Wheat.

a b c

Figure 2.38 Fungi kingdom: (a) The hair-like filaments of the yeast Candida albicans as seen under a microscope. (b) Mould. (c) Mushrooms.


Activity: Class discussionA class discussion is a great way to start this topic. Ask

students to volunteer information about the different

types of living things on the Earth. Most students will

easily identify plants and animals, but may struggle with

the other kingdoms. Discuss why we need more than

just two groups to classify all life on

the Earth.

The continuous development of technology is

critical for classification. It is important for students

to understand that the classification of all species

is constantly under review as new information is

discovered. This idea can be linked to the reclassification

of Pluto from being a planet to being a dwarf planet

based on the new discovery of the shape of its orbit.

Differentiation

For less able students:• Studentswilldevelopanunderstandingbybuilding

a set of examples describing the characteristics of

the individual species and then explaining why that

species belongs to a particular kingdom.

For more able students:• Studentscandealwiththeabstractconceptsand

generalisations, and may research in greater depth

some aspects of the differences between kingdom

groups and the arguments if the number of kingdoms

were changed. If using the envoy teaching strategy,

choose more able students to be the envoys. Less able

students may work together to report the work of

other groups when their envoy returns.

already know; W – what they want to know;

L – new information they have learned). This

strategy then also becomes a summary activity

and helps reflection on the effectiveness of

teaching and student learning.

The basis of constructivist teaching is that

student experience is used to challenge

existing understanding, and to build and

link new concepts. Expose the students to as

many examples of the less familiar kingdoms

as you can. Biological supply companies can

provide you with slime moulds and other

specimens. Even though microscope work

is largely introduced in the next chapter on

cells, students are always fascinated by water

fleas, a range of mushrooms (easily purchased

from shops), and organisms from creeks and

freshwater ponds.

Students could construct a table that

summarises the key features of the structure

and function of each classification group. At

the end of the chapter, the class could then

discuss the relationship between structure and

function of living things and their survival,

reproduction and classification.


> Weblink: This website provides some animal classification cards .

RESOURCES



MoneraThis kingdom is made up of the smallest living things. There are about 75 000 named different types of organism in the Monera kingdom and they are all unicellular. They have a cell wall, but it is made from a different chemical to plant cell walls. Bacteria do have DNA, but no nucleus. This is the key feature of this kingdom, and cells without a nucleus or membrane-bound organelles are called prokaryotes. Organisms from all other kingdoms are made from cells that have a true nucleus and membrane bound organelles, like mitochondria, which you will learn about in chapter 3. These types of cells are called eukaryotes.

Bacteria are the most common organisms in this kingdom. Many people think of bacteria as harmful to humans, but this is not always true. Bacteria in the soil break down rubbish and wastes produced by animals (especially us). Without bacteria, mountains of smelly rubbish would surround us. Bacteria have been put to use by humans to make foods, such as cheese and yoghurt.

Bacteria are classified based on a number of different characteristics such as shape, organisation and the stain patterns from particular dyes. Bacterial cells can be round (cocci), rod-shaped (bacilli) or spiral shaped (spirilla).

The cells are then classified based on how they are organised; individuals, in pairs (diplo), in chains (strepto) and in clusters (staphylo) are some examples.

Figure 2.40 Protists as seen under a microscope: (a) Giardia lamblia. (b) Paramecium. (c) Amoeba. (d) Ophiocytium arbuscula.

a cb d

The shape and organisation of the cells often helps name the species. Looking at Figure 2.39, what does the name Streptococcus pyogenes say about the shape and organisation of the bacteria cells?

ProtistaThere are about 55 000 known species of Protista. Their cell structure is more complex than Monera. Often, organisms that don’t fit into any other kingdom will belong in the Protista kingdom. Scientists still debate whether some groups of algae belong here or with plants. Protists range in size from single-celled organisms to much larger ones like kelp (seaweed). Plankton, the tiny sea creatures eaten in their millions by whales, are part of this kingdom. Amoebas, microscopic organisms that change their shape to trap their food, also belong to this group.

Scientists who study microorganisms in the Monera and Protista kingdoms are called microbiologists.

The Protista kingdom is one of the most difficult to classify because of the huge range of diverse organisms. Taxonomists are still arguing about how to classify the organisms within this varied group. Many believe the kingdom should be classified further based on cellular structures, like the presence of chloroplasts, flagella and their methods of gathering nutrition. Research continues in this area and the classification of this kingdom will continue to change as more information and evidence is found.

ACTIVITY 2.3.1: CLASSIFYING INTO KINGDOMS

The scientist whose main role is to classify living things is known as a taxonomist. In this activity, you become the taxonomist.

What you need: ‘Classifying into Kingdoms’ worksheet from your obook or A3 card/paper, scissors, glue.

1 Download the ‘Classifying into Kingdoms’ worksheet from your obook. (Alternatively, this activity can be done online.)

2 Use a double-page spread of your workbook (or a sheet of A3 card or paper) to draw up a table with four columns.

3 Label the columns ‘Animal’, ‘Plant’, ‘Fungi’ and ‘Other (Monera and Protista)’. (You don’t need to distinguish between the Monera and Protista kingdoms.)

4 Cut out each organism from the worksheet and paste it into the correct column.

Remember1 Recall the five kingdoms.2 Recall four features of animals.3 Recall four features of the Monera kingdom.4 Define the characteristics that make up a protist.5 Draw a table to identify the names of scientists who study organisms

within each kingdom.

apply6 Explain how a protist is different from a bacterium.7 Describe the difference between cells in the Plantae and Fungi kingdoms.8 A bacterial species was classified as Staphylobacillus. What would you expect the

cells to look like under a microscope?9 A new organism was found to contain a cell wall but no nucleus. It photosynthesised

and was microscopic. Suggest which kingdom it best fits in and explain your answer.10 Describe the key structural features you would look for to distinguish between

prokaryotic and eukaryotic organisms.

Research11 The five-kingdom system has a few problems, especially with the classification

of Protista. There are now suggestions that three domains should be used over the five-kingdom system. Research the current use of these domains (Archaea, Prokarya and Eukarya). See the section on the Changing face of classification on page 91 for more information.

QUESTIONS 2.3.1: KINGDOMS

c

a

b

Figure 2.39 Bacteria as seen under a microscope: (a) Spirillum volutans. (b) Lactobacillus casei. (c) Streptococcus pyogenes.

2.3 ClaSSIFICaTIOn TODay 7776 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4

SYLLABUS LINKS


Knowledge and understanding LW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).Students:d identify some examples of groups of

microorganisms





Activity 2.3.1: Classifying into kingdomsSC4-4WS Questioning and predictingSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-9WS Communicating


capability• Literacy

Activity: Cooperative jigsawCooperative jigsaws are an ideal way to investigate the

different kingdoms. Students will need to be in home

groups of five students; allocate each member of a home

group a specific kingdom. Students go into their expert

groups (one for each kingdom) to research in more

detail the characteristics and examples of each group.

Students return to home groups, where each student

contributes their expert knowledge about a kingdom

and the group collates the information into a table. As

a class, discuss the structure of the table—the headings

on rows and columns. This is an ideal situation to teach

students how to develop and use databases.

Summary activityStudents use the database of animals (see

Further Resources) to research in detail

five different animals. They then use an

additional source in an attempt to verify

the information. Discuss with students the

need to crosscheck sources of information.

This can be tricky when using the Internet

because many sites ‘cut and paste’ from other

sources—finding the same information twice

does not make it correct. One way to ensure

accurate information is to use sites from

academic institutions and museums.

Discuss the characteristics of databases.

How might this database be different from

the Encyclopedia of Life database (see Deeper

Understanding in Section 2.1) Students could

use index cards (such as the old library ones)

to develop a paper model of a database. How

would they use the cards to conduct searches?

If student groups have each developed a

database of the five kingdoms, they could

peer evaluate the other groups’ databases. The

envoy model of cooperative learning could be

used to exchange ideas and databases.



MoneraThis kingdom is made up of the smallest living things. There are about 75 000 named different types of organism in the Monera kingdom and they are all unicellular. They have a cell wall, but it is made from a different chemical to plant cell walls. Bacteria do have DNA, but no nucleus. This is the key feature of this kingdom, and cells without a nucleus or membrane-bound organelles are called prokaryotes. Organisms from all other kingdoms are made from cells that have a true nucleus and membrane bound organelles, like mitochondria, which you will learn about in chapter 3. These types of cells are called eukaryotes.

Bacteria are the most common organisms in this kingdom. Many people think of bacteria as harmful to humans, but this is not always true. Bacteria in the soil break down rubbish and wastes produced by animals (especially us). Without bacteria, mountains of smelly rubbish would surround us. Bacteria have been put to use by humans to make foods, such as cheese and yoghurt.

Bacteria are classified based on a number of different characteristics such as shape, organisation and the stain patterns from particular dyes. Bacterial cells can be round (cocci), rod-shaped (bacilli) or spiral shaped (spirilla).

The cells are then classified based on how they are organised; individuals, in pairs (diplo), in chains (strepto) and in clusters (staphylo) are some examples.

Figure 2.40 Protists as seen under a microscope: (a) Giardia lamblia. (b) Paramecium. (c) Amoeba. (d) Ophiocytium arbuscula.

a cb d

The shape and organisation of the cells often helps name the species. Looking at Figure 2.39, what does the name Streptococcus pyogenes say about the shape and organisation of the bacteria cells?

ProtistaThere are about 55 000 known species of Protista. Their cell structure is more complex than Monera. Often, organisms that don’t fit into any other kingdom will belong in the Protista kingdom. Scientists still debate whether some groups of algae belong here or with plants. Protists range in size from single-celled organisms to much larger ones like kelp (seaweed). Plankton, the tiny sea creatures eaten in their millions by whales, are part of this kingdom. Amoebas, microscopic organisms that change their shape to trap their food, also belong to this group.

Scientists who study microorganisms in the Monera and Protista kingdoms are called microbiologists.

The Protista kingdom is one of the most difficult to classify because of the huge range of diverse organisms. Taxonomists are still arguing about how to classify the organisms within this varied group. Many believe the kingdom should be classified further based on cellular structures, like the presence of chloroplasts, flagella and their methods of gathering nutrition. Research continues in this area and the classification of this kingdom will continue to change as more information and evidence is found.

ACTIVITY 2.3.1: CLASSIFYING INTO KINGDOMS

The scientist whose main role is to classify living things is known as a taxonomist. In this activity, you become the taxonomist.

What you need: ‘Classifying into Kingdoms’ worksheet from your obook or A3 card/paper, scissors, glue.

1 Download the ‘Classifying into Kingdoms’ worksheet from your obook. (Alternatively, this activity can be done online.)

2 Use a double-page spread of your workbook (or a sheet of A3 card or paper) to draw up a table with four columns.

3 Label the columns ‘Animal’, ‘Plant’, ‘Fungi’ and ‘Other (Monera and Protista)’. (You don’t need to distinguish between the Monera and Protista kingdoms.)

4 Cut out each organism from the worksheet and paste it into the correct column.

Remember1 Recall the five kingdoms.2 Recall four features of animals.3 Recall four features of the Monera kingdom.4 Define the characteristics that make up a protist.5 Draw a table to identify the names of scientists who study organisms

within each kingdom.

apply6 Explain how a protist is different from a bacterium.7 Describe the difference between cells in the Plantae and Fungi kingdoms.8 A bacterial species was classified as Staphylobacillus. What would you expect the

cells to look like under a microscope?9 A new organism was found to contain a cell wall but no nucleus. It photosynthesised

and was microscopic. Suggest which kingdom it best fits in and explain your answer.10 Describe the key structural features you would look for to distinguish between

prokaryotic and eukaryotic organisms.

Research11 The five-kingdom system has a few problems, especially with the classification

of Protista. There are now suggestions that three domains should be used over the five-kingdom system. Research the current use of these domains (Archaea, Prokarya and Eukarya). See the section on the Changing face of classification on page 91 for more information.

QUESTIONS 2.3.1: KINGDOMS

c

a

b

Figure 2.39 Bacteria as seen under a microscope: (a) Spirillum volutans. (b) Lactobacillus casei. (c) Streptococcus pyogenes.


7 Cells in the Plantae kingdom gain energy by making their own food from sunlight, whereas those in the Fungi kingdom do not. (Plant cells make food whereas fungi cells break down organic matter.)

8 Under a microscope you would expect Stapyhlobacillus bacterial cells to be rod shaped and arranged in clusters.

9 This new organism is probably best classified into Monera because it does not have a nucleus. All prokaryotes are monerans.

10 Organisms in Monera are prokaryotic and do not have a true nucleus or membrane-bound organelles, whereas all the organisms in Protista do have membrane nuclei and other organelles.

11 Student responses will vary but should outline the key feature of each domain as:

• Prokarya(bacteria)–prokaryoticorganismswithout a true nucleus or membrane-bound organelles

• Archaea–unicellular,prokaryoticorganismsthatlive in extreme conditions and have remained relatively the same for billions of years

• Eukarya–eukaryoticorganismsthathaveatruenucleus and membrane-bound organelles.

ANSWERS

QUESTIONS 2.3.1 Kingdoms1 The five kingdoms are Animalia, Plantae,

Fungi, Monera, Protista.

2 Living things in the Animalia kingdom are multicellular, their cells lack a cell wall, they get energy by ingesting other living things, and they have genetic material in their nucleus.

3 Living things in the Monera kingdom are unicellular, they are simple and small, they have a cell wall, and they lack a nucleus (prokaryotic).

4 The characteristics of protists are extremely varied. Most organisms are classified into this kingdom based on the fact they don’t really fit into any other kingdom. All protists are eukaryotic in that they have a true nucleus and membrane-bound organelles. However, they very greatly in size, can be autotrophic or heterotrophic, and can be unicellular or multicellular (large algae like seaweed).

5 See appendix page 1056 A protist is different from a bacterium

because its cells have a nucleus (they are eukaryotic). As a group, protists are much more varied than bacteria and can be either multicellular or unicellular.


TEACHER OBOOK LINKS > Printable: Classifying into kingdoms > A printable worksheet containing colour images

for students to cut out and classify in Activity 2.3.1 > Risk assessment: Activity 2.3.1 Classifying into

kingdoms > Editable risk assessment of the activity written by

a qualified and experienced laboratory technician

STUDENT OBOOK LINKS > Animal classification cards www.

homeschoolcreations.com/files/Before_FIAR_Animal_Classification.pdf

> Envoy teaching strategy www.brainboxx.co.uk/A3_ASPECTS/pages/TALKenvoy.htm

> Kids’ database of animals www.kidsbiology.com/animals-for-children.php?animal

WORKBOOK OBOOK LINKS > Weblink: Timeline of kingdoms > PBS A Brief History of Life website, where

students can either print or view the timeline in an interactive manner

> Workbook 2.4: Identifying organisms > Editable version of workbook activity, which can

be digitally assigned to students for homework > Interactive: Classifying into kingdoms > Interactive task where students drag and drop

images to classify them into the five kingdoms > Workbook 2.5: Kingdoms of life

RESOURCES



Figure 2.42 (a) Observe external features of the fish. (b) Observe the skeleton of the fish. (c) Cut the prawn in half. (d) Observe the outside of the squid.

aimTo examine the skeletal structures of three marine organisms.

Materials• 1 fish (whole)• 1 prawn• 1 squid• Newspaper• Dissecting board• Dissecting kit• Vinyl or latex gloves • Always wear gloves when handling the animals.• The animals must always be on the dissecting board when handling

and dissecting.

Method1 Observe the external features of the fish.2 Carefully cut the fish in half lengthways so you can see the internal

skeleton.3 Observe the skeleton of the fish.4 Feel the outside of the prawn and then peel it.5 Cut the prawn in half and observe the inside.6 Feel the outside of the squid and then cut it in half.7 Observe the inside of the squid.

Results• Draw labelled diagrams of each specimen’s skeleton.

Discussion1 Consider the fish.

a Where is the skeleton of the fish located?b What is this type of skeleton called?

2 Consider the prawn.a Where is the skeleton of the prawn located?b What is this type of skeleton called?

3 Does the squid have a skeleton?4 In which group of animals (vertebrate or invertebrate) would you

place each of the organisms observed? Why?5 What are you: a vertebrate or an invertebrate?

ConclusionWhat types of skeleton are possible? Write a sentence to address the aim.

CLASSIFYING ANIMALS

Vertebrate or invertebrate?In the same way as creating any kind of dichotomous key, classifying the animal kingdom first requires a question. The system scientists use to classify animals is based on their structure. The question is: ‘Does this animal have an internal backbone or not?’

Animals such as cats, humans and birds, with an internal skeleton (endoskeleton) are put in a group called vertebrates. Because these animals often have a spinal cord that usually threads its way between the vertebrate bones, the phylum is called

Chordata. Other animals with an external skeleton (exoskeleton), such as beetles and crabs, and those with no skeleton at all, such as slugs, are known as invertebrates.

The kingdom Animalia is divided into up to 36 different phyla (plural of phylum) depending on which taxonomist you speak to. However, nine of these phyla contain the vast majority of all animal species. Only one of these, Chordata, contains vertebrate animals.

All the rest of the phyla contain invertebrate animals.

DEEPER UNDERSTANDING Giant squid dissection released on the web

By Matthew Moore, 5:19PM BST, 18 Jul 2008

A giant squid has been dissected live on the Internet for the first time—and the gory 90-minute clip has been released for public download.

The 39 st [nearly 250 kilogram] creature was carved up by biologists in front of hundreds of onlookers and thousands of web viewers at Melbourne Museum in Victoria, Australia.

The team of scientists provided a running commentary as they revealed the squid’s internal organs, including its three hearts and doughnut-shaped brain.

They also established the squid was a female, and cut into her stomach

in an unsuccessful attempt to discover her final meal.

Many people in the audience held handkerchiefs in front of their faces because of the revolting smell.

The rare creature was caught up in fishing nets in May, but this was the first detailed inspection of its body. The corpse took three days to thaw.

Stretching to 40 ft [over 12 metres] in length, it was the longest giant squid ever captured in Australian waters.

But calamari connoisseurs hoping for a feast will be disappointed; female squids are not fit for human consumption because of the amount of ammonia in their bodies.

After tests on the squid are complete it will be sewn back together and put on display in an ethanol solution at the museum.

The full video of the dissection is available to view and download from the Melbourne Museum website.Source: www.telegraph.co.uk/earth/earthnews/3347540/Giant-squid-dissection-released-on-the-web.html

EXPERIMENT 2.3.1: EXAMINING SKELETONS

a

b

c

d

> Scalpels are extremely sharp. Use with great care. > If cut, remove gloves and wash the cut under clean water. Apply

antiseptic to the cut and cover with dressing. Tell your teacher.WaR

nIn

g

Figure 2.41 The giant squid is an invertebrate.


SYLLABUS LINKS



Students:b classify a variety of living things based on




Experiment 2.3.1: Examining SkeletonsSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-9WS Communicating


Starter activity: Classifying animalsAsk students about the difference between the squid

and octopus groups. Some websites have an excellent

comparison (see Further Resources). Discuss the

giant squid: where it lives, what it eats and how it was

discovered.

Teaching strategyThe hands-on investigation of fish and prawn skeletons,

and comparison with the squid, could be supported by a

visit to a natural history museum or observation of more

specimens, e.g. snails, earthworms and butterflies.

Activity: Vertebrate or invertebrate?Students develop their dissection skills and can carry

out risk assessments of the task. They construct a table

to compare the observed features of the three animals

dissected.

Relate this back to classification (vertebrate with

endoskeleton versus invertebrate with exoskeleton or no

skeleton) and the function of a skeleton. Ask students

to identify the function of skeletons (support,

protection, levers to allow movement). They

can then identify the roles of human bones

such as the skull, ribs, femur

and spine.

Compare the role of bones in the human

skeleton with those of fish. Note that

fish require less support because they are

aquatic—they do not have limbs but move

their backbone and fins, and they do not have

lungs that need protection.

Additional informationStage 4 does not emphasise the relationship

between classification and evolution, although

many resources (such as those through

museums) will make the link.

Common misconceptionsScientists recognise the phylum Chordata as a

major group of animals. This phylum includes

all the vertebrates (Vertebrata) and some

groups such as lancelets and tunicates. They

all have a notochord (the axis of support),

nerve cord and pharyngeal slits at some stage

of embryological development. Clarify to



Figure 2.42 (a) Observe external features of the fish. (b) Observe the skeleton of the fish. (c) Cut the prawn in half. (d) Observe the outside of the squid.

aimTo examine the skeletal structures of three marine organisms.

Materials• 1 fish (whole)• 1 prawn• 1 squid• Newspaper• Dissecting board• Dissecting kit• Vinyl or latex gloves • Always wear gloves when handling the animals.• The animals must always be on the dissecting board when handling

and dissecting.

Method1 Observe the external features of the fish.2 Carefully cut the fish in half lengthways so you can see the internal

skeleton.3 Observe the skeleton of the fish.4 Feel the outside of the prawn and then peel it.5 Cut the prawn in half and observe the inside.6 Feel the outside of the squid and then cut it in half.7 Observe the inside of the squid.

Results• Draw labelled diagrams of each specimen’s skeleton.

Discussion1 Consider the fish.

a Where is the skeleton of the fish located?b What is this type of skeleton called?

2 Consider the prawn.a Where is the skeleton of the prawn located?b What is this type of skeleton called?

3 Does the squid have a skeleton?4 In which group of animals (vertebrate or invertebrate) would you

place each of the organisms observed? Why?5 What are you: a vertebrate or an invertebrate?

ConclusionWhat types of skeleton are possible? Write a sentence to address the aim.

CLASSIFYING ANIMALS

Vertebrate or invertebrate?In the same way as creating any kind of dichotomous key, classifying the animal kingdom first requires a question. The system scientists use to classify animals is based on their structure. The question is: ‘Does this animal have an internal backbone or not?’

Animals such as cats, humans and birds, with an internal skeleton (endoskeleton) are put in a group called vertebrates. Because these animals often have a spinal cord that usually threads its way between the vertebrate bones, the phylum is called

Chordata. Other animals with an external skeleton (exoskeleton), such as beetles and crabs, and those with no skeleton at all, such as slugs, are known as invertebrates.

The kingdom Animalia is divided into up to 36 different phyla (plural of phylum) depending on which taxonomist you speak to. However, nine of these phyla contain the vast majority of all animal species. Only one of these, Chordata, contains vertebrate animals.

All the rest of the phyla contain invertebrate animals.

DEEPER UNDERSTANDING Giant squid dissection released on the web

By Matthew Moore, 5:19PM BST, 18 Jul 2008

A giant squid has been dissected live on the Internet for the first time—and the gory 90-minute clip has been released for public download.

The 39 st [nearly 250 kilogram] creature was carved up by biologists in front of hundreds of onlookers and thousands of web viewers at Melbourne Museum in Victoria, Australia.

The team of scientists provided a running commentary as they revealed the squid’s internal organs, including its three hearts and doughnut-shaped brain.

They also established the squid was a female, and cut into her stomach

in an unsuccessful attempt to discover her final meal.

Many people in the audience held handkerchiefs in front of their faces because of the revolting smell.

The rare creature was caught up in fishing nets in May, but this was the first detailed inspection of its body. The corpse took three days to thaw.

Stretching to 40 ft [over 12 metres] in length, it was the longest giant squid ever captured in Australian waters.

But calamari connoisseurs hoping for a feast will be disappointed; female squids are not fit for human consumption because of the amount of ammonia in their bodies.

After tests on the squid are complete it will be sewn back together and put on display in an ethanol solution at the museum.

The full video of the dissection is available to view and download from the Melbourne Museum website.Source: www.telegraph.co.uk/earth/earthnews/3347540/Giant-squid-dissection-released-on-the-web.html

EXPERIMENT 2.3.1: EXAMINING SKELETONS

a

b

c

d

> Scalpels are extremely sharp. Use with great care. > If cut, remove gloves and wash the cut under clean water. Apply

antiseptic to the cut and cover with dressing. Tell your teacher.WaR

nIn

g

Figure 2.41 The giant squid is an invertebrate.


students that organisms are still classified as

chordates if they possess the notochord at

some stage of development, even if they do

not have a spine. The sea squirt or cunjevoi

is a chordate that is not a vertebrate, which

students may be familiar with.

Differentiation

For less able (or all) students:• Studentscanidentifytheequipmentused

in the giant squid dissection and compare

it with the equipment they are going to

use when they do the three dissections

in Experiment 2.3.1. They can identify

risks and establish rules for using the

equipment.

For more able students:• Studentscanresearchthephylum

Mollusca and determine which class squid,

cuttlefish, nautilus and octopus are found

in. They can compare the groups and

determine which groups are most closely

related, justifying their decisions.

Summary activityStudents can construct a table to compare the three ways

fish, prawn and squid bodies are supported and have

skeletons that allow movement. It is worth comparing

the way fish swim with the way prawns and squid move.

Show online videos of squid swimming (see Further

Resources). Point out that squid can move quickly, as do

octopus, by jet propulsion (this is a bit difficult to catch

on video).

Extension activitiesSeveral online videos show underwater shots of

spectacular animals. The mimic octopus is fascinating—

students could discuss whether it could carry out its

deception if it had a skeleton or any hard parts.

EXPERIMENT 2.3.1 Examining skeletons

Safety Latex has been known to cause allergic and anaphylaxis reactions. Vinyl gloves are recommended.

Laboratory technician notes If given time, fishmongers and markets will supply whole squid, whole or filleted fish, and prawns.

Class clean-up Collect dirty scalpels and keep them separate from other dissection equipment, to avoid cuts. Ask the laboratory technician to clean these.

All other equipment should be washed in hot soapy water. Ensure sinks are free from specimen parts, as they will smell.

Wrap all specimens and dirty gloves in newspaper, place in a sealed bag, and place them in the bin.

Discussion 1 a The skeleton of the fish is inside its body.

b This type of skeleton is called an endoskeleton.2 a The skeleton of the prawn is outside its body.

b This type of skeleton is called an exoskeleton.3 A squid does not have a skeleton; however, it has an

internal gladius to support the mantle.

4 fish – vertebrate; prawn – vertebrate; squid – invertebrate

5 Humans are vertebrates and have an endoskeleton.

Conclusion Two types of skeleton are possible: internal

(endoskeleton) and external (exoskeleton). Squid have

no skeleton.




MARSUPIALS

⋅ Young are born at a very early stage of development

⋅ Further development occurs in a pouch ⋅ Young receive milk from a teat located in the pouch ⋅ E.g. Wallaby

Remember1 Animals are divided into two main groups.

a Identify the names of the groups.b Explain what the names of these two groups mean.

2 Identify two examples of animals with an exoskeleton.3 Identify two examples of animals with no skeleton at all.

apply4 Explain why invertebrates are such a dominant group among animals.5 Draw a diagram of the world’s biggest invertebrate and write down its dimensions,

for example, its length and weight.6 Why do you think dissecting a giant squid live on the Internet was so interesting to

so many people? Do you find it interesting? Explain.7 Classify the following animals as vertebrates or invertebrates and copy and

complete the table.

vertebrate (endoskeleton)Invertebrate

Exoskeleton no skeleton

Research8 Use the Internet to determine the nine biggest animal phyla. Record their scientific

and common names and list at least three animals from each phylum.9 There are some animals included in the Chordata phylum that are very strange,

including tunicates and hagfish. Find out a little more about them and explain why they have been placed in the Chordata phylum.

QUESTIONS 2.3.2: CLASSIFYING ANIMALS CLASSIFYING VERTEBRATESVertebrates are animals with a spine or backbone. Vertebrates as a group can be broken down into further subgroups called classes. Scientists group vertebrates according to:

• their body covering

• how they obtain oxygen (gills/lungs)

• how their young are born

• how they control their body temperature.

Vertebrates can either generate their own body heat or rely on absorbing heat from their environment. Those that generate their own heat are called endotherms and tend to have a constant body temperature. Those that rely on absorbing heat from their surroundings are called ectotherms. They often have behaviours such as ‘sunning’ themselves to raise their body temperature sufficiently so they can become active.

Class MammaliaMammalia is a class of vertebrates well known to many people. Many of our pets belong to this class: horses, dogs, cats, rabbits, guinea pigs and mice. We belong to this class too. Mammals are animals with hair or fur and they have a relatively constant body temperature. But this class gets its name from mammary glands, which produce milk. It is usually the females that produce the milk to feed their young, but all mammals have mammary glands.

The class Mammalia can be further broken down into three subgroups (Figure 2.43). The main feature used to separate mammals is the way in which their young develop. Placental mammals give birth to relatively well-developed young, marsupial young develop mostly in the pouch rather than in the womb and monotremes lay eggs. However, no matter the type of mammal, they all feed their young milk.

One type of monotreme, the platypus, caused considerable controversy when it was first scientifically studied because it seemed

to have a blend of mammal, reptile and bird characteristics. For a long time it was believed that platypuses could not maintain their body temperature as did endothermic mammals. Studies by an Australian scientist, Tom Grant, have shown that even when platypuses are feeding in icy water, their body temperature remains within a small fixed range. Other scientists have done genetic studies to clarify the links that the platypus has with mammals, reptiles and birds.

MONOTREMES

⋅ Young partially develop in leathery-shelled eggs ⋅ Young hatch underdeveloped from the egg and

require intensive nurturing in either a shallow pouch or burrow

⋅ Young suckle from milk patches on mother’s abdomen

⋅ E.g. Platypus and echidna

PLACENTAL MAMMALS

⋅ Young develops inside mother’s womb ⋅ Young are well developed when born ⋅ Mother produces milk from mammary glands ⋅ E.g. Dingo

Figure 2.43 The three subgroups of mammal.

Lizard

Sting ray

LobsterSea anemone

Earth wormRedback spider

Cow

Sea sponge

Sea star

Galah

Bumblebee

Praying mantis

Snail


SYLLABUS LINKS








ANSWERS

Question 2.3.2: Classifying animals1 a Animals are divided into two main groups:

vertebrates and invertebrates.

b Vertebrates have an endoskeleton (internal skeleton). Invertebrates have no internal skeleton; they may have an exoskeleton (external skeleton) or no skeleton.

2 Examples of animals with an exoskeleton are beetles, crabs, grasshoppers and cockroaches.

3 Examples of animals with no skeleton are worms, snails, slugs, jellyfish, sea stars and leeches.

4 Invertebrates are such a dominant group because of their size. Their (usually) small size allows them to occupy a wide variety of habitats as well as many microhabitats that may not be visible to the eye. Their exoskeleton may also help to protect the members of this group.

5 The world’s biggest known invertebrate is the giant squid. Total length is around 10–13 m, and mass is around 150–275 kg.

6 Dissecting a giant squid live on the Internet is interesting to so many people because most people have not seen something this big before, nor have they seen a dissection done in such a way. Also, the commentary allowed viewers to understand what was going on.

7

Vertebrate (endoskeleton)Invertebrate

Exoskeleton No skeletonLizard Praying mantis Sea spongeCow Sea star SnailSting ray Lobster Sea anemoneGalah Redback spider Earthworm Bumblebee

8 The nine biggest animal phyla are:

• Cnidaria(stingingcells):boxjellyfish,sea anemone, comb jelly

• Mollusca(soft):octopus,snails,oysters• Annelida(ringedorsegmentedworms):

earthworms, leeches, giant tube worm

• Arthropoda(jointedfeet):crabs,spiders, flies

• Platyhelminthes(flatworms):tapeworm, blood flukes, liver flukes

• Nematoda(roundworms):roundworm,threadworm, heartworm



MARSUPIALS

⋅ Young are born at a very early stage of development

⋅ Further development occurs in a pouch ⋅ Young receive milk from a teat located in the pouch ⋅ E.g. Wallaby

Remember1 Animals are divided into two main groups.

a Identify the names of the groups.b Explain what the names of these two groups mean.

2 Identify two examples of animals with an exoskeleton.3 Identify two examples of animals with no skeleton at all.

apply4 Explain why invertebrates are such a dominant group among animals.5 Draw a diagram of the world’s biggest invertebrate and write down its dimensions,

for example, its length and weight.6 Why do you think dissecting a giant squid live on the Internet was so interesting to

so many people? Do you find it interesting? Explain.7 Classify the following animals as vertebrates or invertebrates and copy and

complete the table.

vertebrate (endoskeleton)Invertebrate

Exoskeleton no skeleton

Research8 Use the Internet to determine the nine biggest animal phyla. Record their scientific

and common names and list at least three animals from each phylum.9 There are some animals included in the Chordata phylum that are very strange,

including tunicates and hagfish. Find out a little more about them and explain why they have been placed in the Chordata phylum.

QUESTIONS 2.3.2: CLASSIFYING ANIMALS CLASSIFYING VERTEBRATESVertebrates are animals with a spine or backbone. Vertebrates as a group can be broken down into further subgroups called classes. Scientists group vertebrates according to:

• their body covering

• how they obtain oxygen (gills/lungs)

• how their young are born

• how they control their body temperature.

Vertebrates can either generate their own body heat or rely on absorbing heat from their environment. Those that generate their own heat are called endotherms and tend to have a constant body temperature. Those that rely on absorbing heat from their surroundings are called ectotherms. They often have behaviours such as ‘sunning’ themselves to raise their body temperature sufficiently so they can become active.

Class MammaliaMammalia is a class of vertebrates well known to many people. Many of our pets belong to this class: horses, dogs, cats, rabbits, guinea pigs and mice. We belong to this class too. Mammals are animals with hair or fur and they have a relatively constant body temperature. But this class gets its name from mammary glands, which produce milk. It is usually the females that produce the milk to feed their young, but all mammals have mammary glands.

The class Mammalia can be further broken down into three subgroups (Figure 2.43). The main feature used to separate mammals is the way in which their young develop. Placental mammals give birth to relatively well-developed young, marsupial young develop mostly in the pouch rather than in the womb and monotremes lay eggs. However, no matter the type of mammal, they all feed their young milk.

One type of monotreme, the platypus, caused considerable controversy when it was first scientifically studied because it seemed

to have a blend of mammal, reptile and bird characteristics. For a long time it was believed that platypuses could not maintain their body temperature as did endothermic mammals. Studies by an Australian scientist, Tom Grant, have shown that even when platypuses are feeding in icy water, their body temperature remains within a small fixed range. Other scientists have done genetic studies to clarify the links that the platypus has with mammals, reptiles and birds.

MONOTREMES

⋅ Young partially develop in leathery-shelled eggs ⋅ Young hatch underdeveloped from the egg and

require intensive nurturing in either a shallow pouch or burrow

⋅ Young suckle from milk patches on mother’s abdomen

⋅ E.g. Platypus and echidna

PLACENTAL MAMMALS

⋅ Young develops inside mother’s womb ⋅ Young are well developed when born ⋅ Mother produces milk from mammary glands ⋅ E.g. Dingo

Figure 2.43 The three subgroups of mammal.

Lizard

Sting ray

LobsterSea anemone

Earth wormRedback spider

Cow

Sea sponge

Sea star

Galah

Bumblebee

Praying mantis

Snail


• Echinodermata(spinyskinned):seaurchins, sea stars, brittle stars

• Chordata(spinalchord):humans,seasquirts, eagle

9 Tunicates (sea squirts) are primitive chordates. The primitive spinal chord (notochord) disappears as the animal reaches maturity.

Hagfish have a spinal chord, but no vertebrae to protect it. They do have a skull, but it is made out of cartilage rather than bone.

existing knowledge about the classification of mammals.

A Linnaean hierarchy could be put on display and

students could add specific examples to it as they learn

more about the different classifications of the kingdom

Animalia.

Common misconceptionsThe key characteristic of mammals is not the presence

of fur or hair (some whales and dolphins do not have

any) but the presence of mammary glands—the ability to

produce milk.

Extension activityIt is worth using several case studies to fill in the gap

between the overarching kingdom level and the genus and

species levels identified in Linnaeus’s binomial naming.

This is probably best done with the familiar group,

mammals. Students could become familiar with some of

the common orders and families such as primates or the

cat outlined in Section 2.2 of the student book.

Starter activity: Classifying vertebratesAsk students to list the variety of ways

vertebrates address the four main features

identified in the student book as the basis of

classification of the vertebrate classes. This

builds on student prior knowledge and the

interest they have in these familiar groups.

Activity: Linnaean hierachyVertebrate animals are likely to be the

most familiar group of organisms for the

students. Encourage them to share any

STUDENT OBOOK LINKS

Weblink: Classifying life activity > PBS website where students can complete a

classifying activity from kingdom to species

RESOURCES



Figure 2.44 The short-beaked echidna.

LITERACY FOCUS Enigma of the echidna

By Doug StewartOne of the most remarkable sights that biologist Peggy Rismiller has seen in her years exploring the Australian bush is that of an echidna sunbathing. The short-beaked echidna, or spiny anteater, ordinarily resembles a spiky ball, like some kind of terrestrial sea urchin. To warm up on a cool morning, however, it will stretch out on the ground ... and lift its spines to let in sunlight. ‘It’s amazing to see,’ Rismiller says. ‘It looks like a rug with spines.’

On a continent teeming with weird mammals, the echidna is one of the weirdest. It has a beak like a bird, spines like a hedgehog, eggs like a reptile, the pouch of a marsupial and the lifespan of an elephant. Elusive and unpredictable, echidnas continue to perplex the scientific world with their oddities.

Along with the platypus, the echidna is the world’s only living monotreme, an order of egg-laying mammals found solely in Australasia. ... ‘Echidna’ commonly refers to the short-beaked echidna, which is found across Australia. A second genus, the long-beaked echidna, lives in Papua New Guinea.

The first detailed description of the echidna was published in England in 1792. A decade later, another account included a drawing by Captain William Bligh, who had feasted on roast echidna years earlier during a stopover in Australia. Bligh had the foresight to sketch the strange animal before eating it. Not until 1884 did the scientific world learn, to its amazement, that both platypuses and echidnas laid eggs.

... After mating, an adult female lays a single egg about the size of a five-cent coin directly into her pouch. The newborn puggle (baby echidna) that hatches about ten days later stays in the pouch for several weeks to suckle from the milk its mother secretes.

... Australians have adopted the short-beaked echidna as a national mascot of sorts ... The echidna’s total numbers are unknown ... Concerned that their future welfare is not assured, Australia has officially listed them as a protected species.

Source: www.nwf.org/News-and-Magazines/National-Wildlife/Animals/Archives/2003/

Questions

1 Two different types of echidna exist today. Where does each live and how are they different?

2 Do you consider the echidna to be weird? Explain.

3 Why do you think that scientists who had not seen echidnas for themselves might have believed pictures to be false?

4 Identify the two monotremes and where they can be found.

Class AvesAll birds in the phylum Chordata belong in this class. Like mammals, they are endotherms (having constant body temperatures). Some of their main distinguishing characteristics (the way they differ from the other classes) include their covering of feathers and their scaly legs. All animals in this class lay eggs with a hard shell.

Class ReptiliaThe skin of reptiles, such as snakes and lizards, is usually covered in a layer of fine scales. Reptiles use lungs to breathe, even if they live under water (for example, sea snakes). These animals are also ectotherms—scientists do not use the term ‘cold-blooded’ to describe these animals because a lizard that has been lying in the sun has very warm blood, even though at night its blood is cool.

Class AmphibiaLike reptiles, amphibians are ectotherms; however, their skin is usually soft and slimy to touch. They lay their eggs, without shells, in water. For the first part of their life they have gills and live in the water. As they get older, lungs develop and they become able to live on the land. The only remaining group of amphibians in Australia is frogs. In other parts of the world, caecilians and salamanders may be found.

Class PiscesMost fish are ectotherms. They are covered in a layer of scales and most have fins. They spend all their life in water and so need gills for breathing. Fish are further grouped according to their skeleton. Sharks, rays and skates have a skeleton made entirely of cartilage, while all other fish have bony skeletons.

Figure 2.45 Class Aves: (a) Cockatoo. (b) Vulture.

a b

Figure 2.46 Class Reptilia: (a) Bearded dragon. (b) Gecko.

a

b

Figure 2.47 Class Amphibia: (a) Chinese giant salamander. (b) Growling grass frog.

a b

Figure 2.48 Class Pisces: (a) Reef shark. (b) Weedy sea dragon.

a

b


SYLLABUS LINKS







Working scientificallyLiteracy Builder: Enigma of the echidnaSC4-7WS Processing and analysing data and informationSC4-9WS Communicating


Activity: Vertebrate classesStudents can construct a KWL table and complete each

of the first two columns about mammals, birds, reptiles,

amphibians and fish.

Divide the class into five groups. Each group

researches case studies of examples of mammals, birds,

reptiles, amphibians and fish, and share their findings

with the class. This helps to build a picture of the key

characteristics of each group and their diversity. Students

can then complete their KWL table.

The ‘Enigma of the echidna’ literacy focus can be

used for further research and discussion. The short-

beaked echidna has undergone at least three changes in

scientific name. Use this as an example of how increases

in knowledge and understanding of a species can change

its classification.

Common misconceptions• All birds fly. Discuss examples of small and

large birds that do not fly.

• All things that fly are birds. Many insects

are obvious exceptions, but you can

discuss bats as a group of mammals and

compare the ways that they fly with birds.

It is also worth considering organisms

that glide.

Activity: Vertebrate quizStudents work in groups to develop ten questions

and their answers for a quiz on vertebrates.

These questions are collated and used in a class

trivia competition. This can be used as formative

assessment and the appropriate revision planned.

Differentiation

For less able students:• Providescaffoldingquestionsforthe

case studies and support students while

researching, providing suitable material

if necessary.



Figure 2.44 The short-beaked echidna.

LITERACY FOCUS Enigma of the echidna

By Doug StewartOne of the most remarkable sights that biologist Peggy Rismiller has seen in her years exploring the Australian bush is that of an echidna sunbathing. The short-beaked echidna, or spiny anteater, ordinarily resembles a spiky ball, like some kind of terrestrial sea urchin. To warm up on a cool morning, however, it will stretch out on the ground ... and lift its spines to let in sunlight. ‘It’s amazing to see,’ Rismiller says. ‘It looks like a rug with spines.’

On a continent teeming with weird mammals, the echidna is one of the weirdest. It has a beak like a bird, spines like a hedgehog, eggs like a reptile, the pouch of a marsupial and the lifespan of an elephant. Elusive and unpredictable, echidnas continue to perplex the scientific world with their oddities.

Along with the platypus, the echidna is the world’s only living monotreme, an order of egg-laying mammals found solely in Australasia. ... ‘Echidna’ commonly refers to the short-beaked echidna, which is found across Australia. A second genus, the long-beaked echidna, lives in Papua New Guinea.

The first detailed description of the echidna was published in England in 1792. A decade later, another account included a drawing by Captain William Bligh, who had feasted on roast echidna years earlier during a stopover in Australia. Bligh had the foresight to sketch the strange animal before eating it. Not until 1884 did the scientific world learn, to its amazement, that both platypuses and echidnas laid eggs.

... After mating, an adult female lays a single egg about the size of a five-cent coin directly into her pouch. The newborn puggle (baby echidna) that hatches about ten days later stays in the pouch for several weeks to suckle from the milk its mother secretes.

... Australians have adopted the short-beaked echidna as a national mascot of sorts ... The echidna’s total numbers are unknown ... Concerned that their future welfare is not assured, Australia has officially listed them as a protected species.

Source: www.nwf.org/News-and-Magazines/National-Wildlife/Animals/Archives/2003/

Questions

1 Two different types of echidna exist today. Where does each live and how are they different?

2 Do you consider the echidna to be weird? Explain.

3 Why do you think that scientists who had not seen echidnas for themselves might have believed pictures to be false?

4 Identify the two monotremes and where they can be found.

Class AvesAll birds in the phylum Chordata belong in this class. Like mammals, they are endotherms (having constant body temperatures). Some of their main distinguishing characteristics (the way they differ from the other classes) include their covering of feathers and their scaly legs. All animals in this class lay eggs with a hard shell.

Class ReptiliaThe skin of reptiles, such as snakes and lizards, is usually covered in a layer of fine scales. Reptiles use lungs to breathe, even if they live under water (for example, sea snakes). These animals are also ectotherms—scientists do not use the term ‘cold-blooded’ to describe these animals because a lizard that has been lying in the sun has very warm blood, even though at night its blood is cool.

Class AmphibiaLike reptiles, amphibians are ectotherms; however, their skin is usually soft and slimy to touch. They lay their eggs, without shells, in water. For the first part of their life they have gills and live in the water. As they get older, lungs develop and they become able to live on the land. The only remaining group of amphibians in Australia is frogs. In other parts of the world, caecilians and salamanders may be found.

Class PiscesMost fish are ectotherms. They are covered in a layer of scales and most have fins. They spend all their life in water and so need gills for breathing. Fish are further grouped according to their skeleton. Sharks, rays and skates have a skeleton made entirely of cartilage, while all other fish have bony skeletons.

Figure 2.45 Class Aves: (a) Cockatoo. (b) Vulture.

a b

Figure 2.46 Class Reptilia: (a) Bearded dragon. (b) Gecko.

a

b

Figure 2.47 Class Amphibia: (a) Chinese giant salamander. (b) Growling grass frog.

a b

Figure 2.48 Class Pisces: (a) Reef shark. (b) Weedy sea dragon.

a

b


For more able students:• Directstudentstoresearchsomeofthe

more unusual examples of each of the

classes of vertebrates, and to collate

information of the diversity across a class.

Structured groups could be used, with

more able students being allocated roles of

greater responsibility.

Extension activityThe characteristics ‘ectothermic’ and

‘endothermic’ are significant in distinguishing

the classes of vertebrate. Explain the

advantages and disadvantages of each.

Endothermic animals control their body

temperature within a narrow range, and

therefore they can regulate their levels of

activity. Endothermic animals require a lot of

energy to generate body heat, so their demand

for food is greater and more frequent.

Because ectothermic organisms are not

generating body heat, they require less food

and some of them eat infrequently. Terrestrial

ectotherms are often subject to fluctuations in

external temperature. They are not completely

in control of their own levels of activity.

Many reptiles find a warm or sunny place to ‘sunbake’

to raise body temperature before they become active.

One example of endothermic behaviour to overcome, to

some extent, the problem of needing food frequently is

hibernation or torpor. Such endotherms, such as bears

in winter, drop their body temperature and go into a

state of ‘sleep’.

Students can construct a PMI table comparing

endothermic and ectothermic behaviours and functions.

ANSWERS

Literacy builder: Enigma of the echidna1 The short-beaked echidna lives in Australia and

a small section of Papua New Guinea. The long-beaked echidna lives only in Papua New Guinea. The short-beaked echidna has longer spines (for defence) and fur between the spines (for insulation). The long-beaked echidna has fewer, shorter spines. The long-beaked echidna is bigger and has a longer snout. The short-beaked echidna eats mainly ants and termites, whereas the long-beaked echidna feeds on earthworms and insects.

2 Echidnas could be considered to be weird. They are mammals that lay eggs like a reptile, have a snout that is used as a mouth and nose, spines like a hedgehog, the pouch of a marsupial, and produces milk like all mammals. The fact that the short-beaked echidna does not sweat or pant but lives widely across arid Australia and can suffer from heat stress (although being nocturnal may help to overcome this problem) also seems weird.

3 If scientists hadn’t seen an echidna for themselves they are likely to have thought the pictures were false because of the oddities of the echidna’s physical appearance.

4 The two monotremes are the echidna and the platypus. The echidna can be found in Papua New Guinea and in Australia. The platypus is only found in Australia.

STUDENT OBOOK LINKS > Weblink: Enigma of the echidna > ABC website where students can watch an

informative video on the echidna > Weblink: Tree of life

This website gives the tree of life for chordates > Interactive: Vertebrate classes > Interactive task where students drag and drop

images to classify different vertebrates

WORKBOOK OBOOK LINKS > Workbook 2.6: Vertebrate classes > Editable version of workbook activity, which can


RESOURCES



MagpieSparrowEagle

Example

Example

Example

Example

Birds

Mamm

alsFis

hRe

ptiles

Amph

ibian

s

Vertebrates

ACTIVITY 2.3.2: WHO ARE THE VERTEBRATES?

vertebrate alphabet graffitiThis task could be completed as a webpage, with images and links to further information about each animal.

1 You will be placed into one of five groups, each of which will be allocated one class of vertebrate.

2 Label an A3 sheet of paper with the name of your class of vertebrate.3 Write the letters of the alphabet down the left-hand side of the page.4 For each letter, write the name of an animal that fits this category.5 When finished, you will have the names of up to 26 different vertebrates. Some

categories will be harder to fill than others.6 Put up the finished sheets around the room.

Jellyfish organiser for vertebratesA jellyfish graphic organiser is a good way to show how subgroups make up a whole. It can also be used to list specific examples at the same time.

1 Individually, go around to each of the five sheets of vertebrates and select six animals from each class.

2 On a full page, draw five ‘jellyfish’ connected to the main group (vertebrates), as shown in Figure 2.49.

3 Label each jellyfish with the class names (fish, reptiles, amphibians, mammals and birds).

4 Write a description of the characteristics of each class in the appropriate body of each jellyfish.

5 Place the six animals you selected along six tentacles on each jellyfish.

QUESTIONS 2.3.3: CLASSIFYING VERTEBRATES

Remember1 Describe the main characteristics of mammals.2 Describe how a baby echidna is born and develops before it comes out of the

mother’s pouch.3 Identify the defining characteristics of each class of mammal.

apply4 Seals have fins like fish and live on the land and in the water like amphibians.

a Investigate how a seal’s young are born.b Given that a seal has long whiskers, to which class of vertebrate do seals

belong?5 A dolphin lives in the ocean and has fins. To which class does it belong? Explain.6 A flying fox can fly through the air like a bird but is covered in fur. To which class

does it belong? Why? Explain.7 Draw a dichotomous key to separate out the different classes of vertebrates.

There are many more invertebrates on the Earth than vertebrates: 96% of all animals are invertebrates. Invertebrates have either an external skeleton (exoskeleton) or no skeleton at all. The giant squid, huge as it is, has no backbone. As well as enormous animals like this, thousands of tiny insects and other creatures belong to the invertebrates group. Invertebrates are classified into several main groups or phyla.

CLASSIFYING INVERTEBRATESInvertebrates are grouped by their

characteristics (in the same way that vertebrates are classified). Characteristics used to classify invertebrates include the presence of a shell or hard cover, tentacles and spiny skin. Organisms with similar features are placed in the same group. The tabular dichotomous key in Table 2.5 can be used to place an organism in a particular phylum. Not all phyla of invertebrates are shown on the key.

Table 2.5 A tabular dichotomous key for classifying invertebrates.

1Body spongy, with many holes Porifera

Body not spongy Go to 2

2Soft body, no shell Go to 3

Outside shell or hard cover Go to 6

3Many tentacles or arms Go to 4

Long body without tentacles Go to 5

4Tentacles around the mouth of a sac-like body Cnidaria

Arms with suction discs Mollusca

5Soft body, large foot Mollusca

Worm-like or leaf-like Nematodata, Platyhelminthes or Annelida

6Proper shell or smooth, hard covering Go to 7

Spiny skin with rough covering Echinodermata

7Limbs in pairs Arthropoda

Shell, no segments, large foot Mollusca

Figure 2.49 A jellyfish organiser for vertebrates.

ARTHROPODS

⋅ Segmented bodies ⋅ Paired and jointed legs ⋅ Exoskeleton ⋅ Examples: insect, spider, centipede, scorpion

PORIFERANS

⋅ Spongy body with holes ⋅ Found in water, attached to rocks ⋅ Examples: breadcrumb sponge, glass sponges

MOLLUSCS

⋅ Soft body ⋅ Usually have a protective shell ⋅ Examples: snail, octopus, oyster, slug


SYLLABUS LINKS









Working scientifically Activity 2.3.2: Who are the vertebrates?SC4-4WS Questioning and predictingSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-9WS Communicating


Starter activity: Classifying invertebratesStudents can follow the links at the Tree of Life website

(see Further Resources) to Arthropoda (insects, spiders,

crabs, etc.). In the Animals section they can see

examples of other invertebrates. Students could choose

an invertebrate animal and present an oral report to

the class to give students an understanding of the vast

diversity of invertebrates.

Teaching strategyFirst-hand investigations backed by searching secondary

sources will engage students in learning about

invertebrates.

Activity: Invertebrate keysStudents may find the student book tabular

key for identifying invertebrates inadequate

for identifying the organisms they discover

in their local environment. Encourage them

to suggest whether it is possible to provide

an adequate key for invertebrates given

the enormous number that are involved.

Obviously, such keys do exist, but the level of

detail they include would not be appropriate

for Year 7 students. It may be worth

pointing out and discussing why molluscs

are identified in three separate places. The

Australian Museum’s Bugwise website (see

Further Resources) has examples of keys for

spiders using the structure of their webs.

The complexity of this activity is closer to

reality, although not at the level of a true

dichotomous key for invertebrates.

ANSWERS

ACTIVITY 2.3.2 Who are the vertebrates?

Vertebrate alphabet graffitiStudents may need to conduct some research to complete all letters of the alphabet. They may also like to research



MagpieSparrowEagle

Example

Example

Example

Example

Birds

Mamm

alsFis

hRe

ptiles

Amph

ibian

s

Vertebrates

ACTIVITY 2.3.2: WHO ARE THE VERTEBRATES?

vertebrate alphabet graffitiThis task could be completed as a webpage, with images and links to further information about each animal.

1 You will be placed into one of five groups, each of which will be allocated one class of vertebrate.

2 Label an A3 sheet of paper with the name of your class of vertebrate.3 Write the letters of the alphabet down the left-hand side of the page.4 For each letter, write the name of an animal that fits this category.5 When finished, you will have the names of up to 26 different vertebrates. Some

categories will be harder to fill than others.6 Put up the finished sheets around the room.

Jellyfish organiser for vertebratesA jellyfish graphic organiser is a good way to show how subgroups make up a whole. It can also be used to list specific examples at the same time.

1 Individually, go around to each of the five sheets of vertebrates and select six animals from each class.

2 On a full page, draw five ‘jellyfish’ connected to the main group (vertebrates), as shown in Figure 2.49.

3 Label each jellyfish with the class names (fish, reptiles, amphibians, mammals and birds).

4 Write a description of the characteristics of each class in the appropriate body of each jellyfish.

5 Place the six animals you selected along six tentacles on each jellyfish.

QUESTIONS 2.3.3: CLASSIFYING VERTEBRATES

Remember1 Describe the main characteristics of mammals.2 Describe how a baby echidna is born and develops before it comes out of the

mother’s pouch.3 Identify the defining characteristics of each class of mammal.

apply4 Seals have fins like fish and live on the land and in the water like amphibians.

a Investigate how a seal’s young are born.b Given that a seal has long whiskers, to which class of vertebrate do seals

belong?5 A dolphin lives in the ocean and has fins. To which class does it belong? Explain.6 A flying fox can fly through the air like a bird but is covered in fur. To which class

does it belong? Why? Explain.7 Draw a dichotomous key to separate out the different classes of vertebrates.

There are many more invertebrates on the Earth than vertebrates: 96% of all animals are invertebrates. Invertebrates have either an external skeleton (exoskeleton) or no skeleton at all. The giant squid, huge as it is, has no backbone. As well as enormous animals like this, thousands of tiny insects and other creatures belong to the invertebrates group. Invertebrates are classified into several main groups or phyla.

CLASSIFYING INVERTEBRATESInvertebrates are grouped by their

characteristics (in the same way that vertebrates are classified). Characteristics used to classify invertebrates include the presence of a shell or hard cover, tentacles and spiny skin. Organisms with similar features are placed in the same group. The tabular dichotomous key in Table 2.5 can be used to place an organism in a particular phylum. Not all phyla of invertebrates are shown on the key.

Table 2.5 A tabular dichotomous key for classifying invertebrates.

1Body spongy, with many holes Porifera

Body not spongy Go to 2

2Soft body, no shell Go to 3

Outside shell or hard cover Go to 6

3Many tentacles or arms Go to 4

Long body without tentacles Go to 5

4Tentacles around the mouth of a sac-like body Cnidaria

Arms with suction discs Mollusca

5Soft body, large foot Mollusca

Worm-like or leaf-like Nematodata, Platyhelminthes or Annelida

6Proper shell or smooth, hard covering Go to 7

Spiny skin with rough covering Echinodermata

7Limbs in pairs Arthropoda

Shell, no segments, large foot Mollusca

Figure 2.49 A jellyfish organiser for vertebrates.

ARTHROPODS

⋅ Segmented bodies ⋅ Paired and jointed legs ⋅ Exoskeleton ⋅ Examples: insect, spider, centipede, scorpion

PORIFERANS

⋅ Spongy body with holes ⋅ Found in water, attached to rocks ⋅ Examples: breadcrumb sponge, glass sponges

MOLLUSCS

⋅ Soft body ⋅ Usually have a protective shell ⋅ Examples: snail, octopus, oyster, slug


further information about some of the more interesting species.

Jellyfish organiser for vertebratesThis could be done as a class activity or students could rotate around the classroom to different vertebrate groups.

QUESTIONS 2.3.3 Classifying vertebrates1 The main characteristics of mammals

are that they give birth to live young and produce milk to feed their young.

2 The echidna egg is laid into a backward-opening pouch and hatches into the pouch10 days later. Hatchings are about

1.5 cm in length and are known as puggles. After hatching, they attach themselves to the mother’s areolae (monotremes lack nipples) to feed on the milk. Juveniles are evicted from the pouch at about 3 months old but will often be left in the nest while the mother is foraging, from when the juvenile starts to develop spines. Weaning occurs at about 6 months of age and the young leave the burrow at about this time. The mother and young don’t have contact after this.

3 The three classes of mammal are defined by their reproductive strategies: monotremes lay eggs; marsupials give

birth to underdeveloped young that further develop in a pouch; placental mammals give birth to relatively well developed young.

4 a Seals give birth to live young, usually on land. The young are well-developed at birth, and grow and develop into self-sufficiency very quickly.

b Seals belong to the Mammalia class of vertebrates.

5 Dolphins belong in the class Mammalia as they give birth to live young and produce milk to feed their young.

6 Flying foxes, although similar in structure to birds, belong to the class Mammalia as they give birth to live young rather than lay eggs and they produce milk to feed their young.

7 Student drawings will vary, but each class should be represented with clear distinguishing features.

LINKS > Tree of Life web project > Dichotomous key to identify spiders by their

webs > Bugwise is an invertebrate guide by the

Australian Museum > Guide to traditional invertebrate collection

methods > Insect photography

TEACHER OBOOK LINKS > Risk assessment: Activity 2.3.2: Who are the

vertebrates? > Editable risk assessment of the activity written


RESOURCES



Invertebrates can be found in just about every different environment on the planet. They have adapted to survive in some of the most extreme conditions from the freezing depths of the ocean to the scorching heat of deserts. Most of the invertebrates we think of tend to be the small bugs, insects and the creepy crawlies. But as you saw earlier, the giant quid is one of the largest invertebrates in the world. Invertebrate Japanese spider crabs can grow to around 3.8 metres from claw to claw. Most of the larger invertebrates live in the ocean or other aquatic environments because the buoyancy of the water means there is less need for body support than is required when living on land.

ACTIVITY 2.3.3: IDENTIFYING INVERTEBRATES

Remember1 Recall what percentage of animals are vertebrates.2 Describe an exoskeleton. Give three examples of organisms with an exoskeleton.3 Beetles have segmented bodies and jointed legs. Identify the phylum to which

they belong.

apply4 Eighty per cent of animals on the Earth are arthropods.

a Explain which characteristic their name refers to. (Hint: ‘arthritis’ and ‘podiatrist’)

b Draw three different arthropods and label the features that make them part of this phylum.

5 In Activity 2.3.3, which phylum of invertebrates did you find in the greatest quantity? Can you explain why?

6 Transform the tabular key in Table 2.5 into a branching dichotomous key.

Research7 The phyla classifications in invertebrates are always changing. Research about an

organism called a brachiopod.a Which phylum does it belong in?b Why is it classified in that way?c How does it obtain its food?d What type of habitats does it live in?e How is it different from a mollusc such as a clam or scallop?

QUESTIONS 2.3.4: CLASSIFYING INVERTEBRATES

What you need: magnifying glass or stereo microscope, Petri dishes, jars with lids, tweezers, vinyl or latex gloves, newspaper

Alternatively, your teacher may provide prepared samples for you to look at. Complete this classification exercise for each prepared sample.

1 Visit a local natural environment (e.g. a garden, beach, park or pond) and observe invertebrate specimens.

2 While wearing gloves, use tweezers to collect up to ten invertebrate specimens in separate jars.

3 Use the tabular key in Table 2.5 to identify the invertebrates to their particular phylum.

4 Use a magnifying glass or stereo microscope to help you sketch each animal. Put in the common name for the animal (if you can) and write its classification group under the drawing.

5 Return the invertebrates to their natural environment after you have finished.

CNIDARIANS

⋅ Soft, hollow body ⋅ Live in water ⋅ Tentacles ⋅ Examples: coral, sea jelly, anemone

PLATYHELMINTHES

⋅ Also called flat worms ⋅ Mostly parasitic ⋅ Have a blind gut (mouth but no anus) ⋅ Examples: tapeworm, blood and liver flukes

ANNELIDS

⋅ Also called segmented worms ⋅ Long cylindrical body that is separated into segments ⋅ Examples: leeches, earthworms

NEMATODES

⋅ Also called round worms ⋅ Long smooth cylindrical body ⋅ Often microscopic ⋅ Examples: round worm,

threadworm, heartworm

ECHINODERMS

⋅ Rough, spiny skin ⋅ Arms radiate from centre of body ⋅ Found in sea ⋅ Examples: sea urchin, sea cucumber, brittle star

> Do not touch any animal that might bite or sting. Check with your teacher if you are unsure.

> Use tweezers to pick up animals. > Place any animal immediately in a jar and put on the lid.W

aRn

Ing


SYLLABUS LINKS








Working scientifically Activity 2.3.3: Identifying invertebratesSC4-4WS – Questioning and predictingSC4-6WS – Conducting investigationsSC4-7WS – Processing and analysing data and informationSC4-9WS – Communicating


Activity: Classifying invertebratesSome students will struggle with the differences between

the three phyla of worms. Split the class up into eight

groups and assign each group a phylum of invertebrates.

Students are to complete a case study of their phylum

and present it to the class. The key features of each

phylum could be displayed around the classroom.

Activity: Identifying invertebratesPlace numbered pictures or specimens of various

invertebrates around the room, or set up computers to

show specimen illustrations from the Bugwise website

(see Further Resources). Students rotate around the

illustrations and identify which phyla of invertebrate

each specimen belongs. Students write one sentence

about each specimen using scientific terms to describe

the specimen. You could make a list of

possible descriptive terms available.

Differentiation

For less able students:• VisittheAustralianMuseumwebsiteto

view entries in the ‘Up close and spineless’

insect photography competition. Ask

students to try this themselves, finding out

a little about the insect they photograph.

For more able students:• Askstudentstoidentifyandresearch

a ‘weird’ invertebrate. Students should

present their findings electronically or as a

poster for the class to view.

Extension activityThis activity could be linked to the Making

Connections information about black

smokers at the end of the chapter. Discuss

why invertebrates are so common in extreme

environments.



Invertebrates can be found in just about every different environment on the planet. They have adapted to survive in some of the most extreme conditions from the freezing depths of the ocean to the scorching heat of deserts. Most of the invertebrates we think of tend to be the small bugs, insects and the creepy crawlies. But as you saw earlier, the giant quid is one of the largest invertebrates in the world. Invertebrate Japanese spider crabs can grow to around 3.8 metres from claw to claw. Most of the larger invertebrates live in the ocean or other aquatic environments because the buoyancy of the water means there is less need for body support than is required when living on land.

ACTIVITY 2.3.3: IDENTIFYING INVERTEBRATES

Remember1 Recall what percentage of animals are vertebrates.2 Describe an exoskeleton. Give three examples of organisms with an exoskeleton.3 Beetles have segmented bodies and jointed legs. Identify the phylum to which

they belong.

apply4 Eighty per cent of animals on the Earth are arthropods.

a Explain which characteristic their name refers to. (Hint: ‘arthritis’ and ‘podiatrist’)

b Draw three different arthropods and label the features that make them part of this phylum.

5 In Activity 2.3.3, which phylum of invertebrates did you find in the greatest quantity? Can you explain why?

6 Transform the tabular key in Table 2.5 into a branching dichotomous key.

Research7 The phyla classifications in invertebrates are always changing. Research about an

organism called a brachiopod.a Which phylum does it belong in?b Why is it classified in that way?c How does it obtain its food?d What type of habitats does it live in?e How is it different from a mollusc such as a clam or scallop?

QUESTIONS 2.3.4: CLASSIFYING INVERTEBRATES

What you need: magnifying glass or stereo microscope, Petri dishes, jars with lids, tweezers, vinyl or latex gloves, newspaper

Alternatively, your teacher may provide prepared samples for you to look at. Complete this classification exercise for each prepared sample.

1 Visit a local natural environment (e.g. a garden, beach, park or pond) and observe invertebrate specimens.

2 While wearing gloves, use tweezers to collect up to ten invertebrate specimens in separate jars.

3 Use the tabular key in Table 2.5 to identify the invertebrates to their particular phylum.

4 Use a magnifying glass or stereo microscope to help you sketch each animal. Put in the common name for the animal (if you can) and write its classification group under the drawing.

5 Return the invertebrates to their natural environment after you have finished.

CNIDARIANS

⋅ Soft, hollow body ⋅ Live in water ⋅ Tentacles ⋅ Examples: coral, sea jelly, anemone

PLATYHELMINTHES

⋅ Also called flat worms ⋅ Mostly parasitic ⋅ Have a blind gut (mouth but no anus) ⋅ Examples: tapeworm, blood and liver flukes

ANNELIDS

⋅ Also called segmented worms ⋅ Long cylindrical body that is separated into segments ⋅ Examples: leeches, earthworms

NEMATODES

⋅ Also called round worms ⋅ Long smooth cylindrical body ⋅ Often microscopic ⋅ Examples: round worm,

threadworm, heartworm

ECHINODERMS

⋅ Rough, spiny skin ⋅ Arms radiate from centre of body ⋅ Found in sea ⋅ Examples: sea urchin, sea cucumber, brittle star

> Do not touch any animal that might bite or sting. Check with your teacher if you are unsure.

> Use tweezers to pick up animals. > Place any animal immediately in a jar and put on the lid.W

aRn

Ing


ANSWERS

Activity 2.3.3: Identifying invertebratesSome students will be a bit squeamish about dealing with ‘creepy crawlies’ so it will probably be best for students to work in pairs or small groups. Emphasise that all collected animals must be returned to where they were found unharmed. A class discussion about the ethical considerations of this task could be very valuable for some students.

Questions 2.3.4: Classifying invertebrates1 About 96% of animals are invertebrates, so

4% of animals are vertebrates.

2 An exoskeleton is an external skeleton. It is usually rigid and the muscles are attached from within. Exoskeletons must be shed to allow the growth of the invertebrate, so animals with exoskeletons go through a period of moulting and regrowing the skeleton. An exoskeleton is a bit like an armour suit, so there have to be joints between the sections of skeleton to allow movement. Examples of organisms with an exoskeleton are crabs, beetles, cockroaches and grasshoppers.

3 Beetles belong to the phylum Arthropoda because they all have segmented bodies and jointed legs.

4 a The word ‘arthropod’ means ‘jointed feet’, which refers to the segmented bodies and jointed legs these organisms have.

b Answers will vary depending on arthropods drawn, but emphasis should be on their jointed legs.

5 Answers will vary based on Activity 2.3.3 results.

7 a Brachiopods belong in a phylum called Brachiopoda.

b Brachi = arm, pod = foot. The shell opens sideways like an arm, but the organism’s inside is a muscular foot.

c Brachiopods filter feed by drawing water through a structure called a lophophore, which channels the food into its digestive system.

d Brachiopods live at the bottom of the ocean.e Brachiopods are a mirror image from side to side

(bilaterally symmetrical). Molluscs, like clams, are a mirror image from top to bottom, at the hinge.

WORKBOOK OBOOK LINKS > Workbook 2.7: Invertebrates > Editable version of workbook activity, which can

be digitally assigned to students for homework > Workbook 2.8: Strange animals > Editable version of workbook activity, which can


TEACHER OBOOK LINKS > Risk assessment: Activity 2.3.3 Identifying

invertebrates > Editable risk assessment of the activity written


RESOURCES



Plants are living things that are essential to the survival of all life on the Earth. Like animals, plants grow and need to reproduce to ensure their survival. These multicellular organisms can make their own food—they are autotrophs.

Plants can be classified in a number of different ways, based on different characteristics. When classifying according to stature (height and shape), plants are divided into mosses, herbs, ferns, shrubs, trees and vines. These groups are defined by the height of the plant and the number and type of stem (woody or herbaceous).

CLASSIFYING PLANTS

Figure 2.51 The mountain ash (Eucalyptus regnans) is a vascular plant.

Figure 2.52 Moss is a non-vascular plant.

Plants are also classified based on whether or not they have veins for efficiently conducting water and nutrients around the plants.• Vascular plants, such as ferns, conifers and flowering plants, contain vein-like

structures. Xylem carry water and minerals up from the roots and phloem carry food (a sugar called glucose) around the plant.

• Non-vascular plants, such as liverworts and mosses, do not have these veins and so must absorb their water and nutrients through the surface of their leaves. This is much more difficult and is why non-vascular plants tend to be very small and are restricted to damp environments.

Plants can also be classified into phyla using their reproductive characteristics and structural features to distinguish them. Four of the most common phyla are Bryophyta (mosses and liverworts), Pteridophyta (ferns), Coniferophyta (conifers) and Anthophyta (flowering plants).

MOSSES

⋅ No true stems ⋅ Usually less than 10 cm

FERNS

⋅ Fronds are grown directly from and evenly around fibrous stem

⋅ Most between 0.5–5 m, but can grow over 30 m

HERBS

⋅ Fleshy stems ⋅ Usually less than 1 m

SHRUBS

⋅ Usually multiple woody stems branching form the base of the plant

⋅ Between 1–5 m

⋅ Typically one main woody stem (trunk)

⋅ Over 5 m

TREES

⋅ Very long stems that can remain flexible or become woody

⋅ Tend to use other plants or structures for support

⋅ Greatly varied in height

VINES

CONIFEROPHYTES

⋅ Large, vascular ⋅ Reproduce by naked seeds, often carried by the wind from

a woody cone ⋅ Needle-like leaves ⋅ Examples: Wollemi pine, Radiata pine, White Cypress pine,

cycad

PTERIDOPHYTES

⋅ Small- to medium-sized, vascular ⋅ Need water for fertilisation and a complete life cycle ⋅ Reproduce by spores on back of leaves ⋅ Have stems, roots, leaves ⋅ Young rolled-up leaves unroll into a feathery frond ⋅ Examples: tree fern, fishbone fern, maidenhair fern

ANTHOPHYTES

⋅ Small to large, vascular ⋅ Reproduce by flowers containing seeds that develop in

the ovary after fertilisation ⋅ Fertilised flower produces seeds and fruit ⋅ Examples: grevillea, waratah, rose

BRYOPHYTES

⋅ Small, non-vascular ⋅ Need a constant supply of water to live and reproduce ⋅ Reproduce by spores in capsules ⋅ Thin leaf-like structures, attach to soil by thread-like

structures called rhizoids ⋅ Examples: peat moss, Marchantia

Figure 2.50 The stature classification of plants.


SYLLABUS LINKS








Starter activity: Classifying plants• As a class, brainstorm a list of plants.

• Watch the first five minutes of the Kew Gardens

Breathing Planet campaign (see Further Resources).

• Ask the class, ‘What if there were no plants?’

The big idea in plant classification is that the groups

represent a transition from primitive plants that lived

in water (and are now grouped with the protists) to

plants living on land. The mosses and liverworts are at

the beginning of the transition, and the flowering plants

are the most highly adapted to living and reproducing

on land. Students can brainstorm changes plants would

need to make to go from living in water to living on

land.

Teaching: StrategyBy far the most prolific group of plants on land is

the Anthophytes. These are also commonly called

angiosperms or flowering plants. The differences

between monocotyledons and dicotyledons could be

introduced, and students given examples to classify. This

could help with completion of Activity 2.3.4. Videos by

David Attenborough contain amazing time-lapse images

of plants that engage students.

Differentiation

For less able students:• Germinatingseedshelpstudentstakean

interest in plants, especially if they are

garden herbs.

For more able students:• Thesestudentscanlearnaboutthephyla

names, e.g. Bryophyta (mosses and

liverworts). Ferns and the seed-bearing

plants are often placed in the same

phylum, Trachaeophyta. Ferns belong to

the division Pteridophyta. Seed plants are

divided into the class of naked seed plants

(gymnosperms) and the class of flowering

plants (angiosperms).



Plants are living things that are essential to the survival of all life on the Earth. Like animals, plants grow and need to reproduce to ensure their survival. These multicellular organisms can make their own food—they are autotrophs.

Plants can be classified in a number of different ways, based on different characteristics. When classifying according to stature (height and shape), plants are divided into mosses, herbs, ferns, shrubs, trees and vines. These groups are defined by the height of the plant and the number and type of stem (woody or herbaceous).

CLASSIFYING PLANTS

Figure 2.51 The mountain ash (Eucalyptus regnans) is a vascular plant.

Figure 2.52 Moss is a non-vascular plant.

Plants are also classified based on whether or not they have veins for efficiently conducting water and nutrients around the plants.• Vascular plants, such as ferns, conifers and flowering plants, contain vein-like

structures. Xylem carry water and minerals up from the roots and phloem carry food (a sugar called glucose) around the plant.

• Non-vascular plants, such as liverworts and mosses, do not have these veins and so must absorb their water and nutrients through the surface of their leaves. This is much more difficult and is why non-vascular plants tend to be very small and are restricted to damp environments.

Plants can also be classified into phyla using their reproductive characteristics and structural features to distinguish them. Four of the most common phyla are Bryophyta (mosses and liverworts), Pteridophyta (ferns), Coniferophyta (conifers) and Anthophyta (flowering plants).

MOSSES

⋅ No true stems ⋅ Usually less than 10 cm

FERNS

⋅ Fronds are grown directly from and evenly around fibrous stem

⋅ Most between 0.5–5 m, but can grow over 30 m

HERBS

⋅ Fleshy stems ⋅ Usually less than 1 m

SHRUBS

⋅ Usually multiple woody stems branching form the base of the plant

⋅ Between 1–5 m

⋅ Typically one main woody stem (trunk)

⋅ Over 5 m

TREES

⋅ Very long stems that can remain flexible or become woody

⋅ Tend to use other plants or structures for support

⋅ Greatly varied in height

VINES

CONIFEROPHYTES

⋅ Large, vascular ⋅ Reproduce by naked seeds, often carried by the wind from

a woody cone ⋅ Needle-like leaves ⋅ Examples: Wollemi pine, Radiata pine, White Cypress pine,

cycad

PTERIDOPHYTES

⋅ Small- to medium-sized, vascular ⋅ Need water for fertilisation and a complete life cycle ⋅ Reproduce by spores on back of leaves ⋅ Have stems, roots, leaves ⋅ Young rolled-up leaves unroll into a feathery frond ⋅ Examples: tree fern, fishbone fern, maidenhair fern

ANTHOPHYTES

⋅ Small to large, vascular ⋅ Reproduce by flowers containing seeds that develop in

the ovary after fertilisation ⋅ Fertilised flower produces seeds and fruit ⋅ Examples: grevillea, waratah, rose

BRYOPHYTES

⋅ Small, non-vascular ⋅ Need a constant supply of water to live and reproduce ⋅ Reproduce by spores in capsules ⋅ Thin leaf-like structures, attach to soil by thread-like

structures called rhizoids ⋅ Examples: peat moss, Marchantia

Figure 2.50 The stature classification of plants.


LINKS > Weblink: Tree of Life web project > Weblink: Kew Gardens Breathing Planet

campaign > Weblink: The Private Life of Plants 1995, BBC

documentary series written and narrated by David Attenborough; available on DVD

WORKBOOK LINKS > Workbook 2.9: Structural features used to

group plants > Editable version of workbook activity, which can


RESOURCES



archaea

bacteria

eukarya

ALL LIFE

DOMAIN cyanobacteria

gram–negative bacteria

gram–positive bacteria

methanogens

halophiles

thermoacidophiles

protista

fungi

plantae

animalia

KINGDOM

ACTIVITY 2.3.4: IDENTIFYING PLANTS

1 Observe and collect small specimens of at least five types of plant from local bushland (not a national park or flora reserve) or your garden. Make pressed, dried specimens. Include notes about where each plant specimen was collected.

2 Make detailed observations of each plant including:• height and width• type of plant (tree, shrub, herbaceous, grass, perennial, annual)• type of bark, if present (smooth, fibrous, hard, furrowed)• shape, smell, texture, size and edge shape of the leaf• evidence of reproduction (spores on leaf, flowers, fruit, nuts, cones).

3 Identify the features the plants have in common.4 List some differences between your plants.

QUESTIONS 2.3.5: CLASSIFYING PLANTS

Remember1 Compare the function of xylem and phloem in vascular plants.2 Describe the key features that would help identify a plant as being an anthophyte.3 Are you likely to find mosses or liverworts growing in the desert? Explain your

answer.

apply4 Using your specimens from Activity 2.3.4, classify your plants as vascular or

non-vascular.5 Some coniferophytes produce seeds with ‘wings’. Suggest a possible advantage

for this adaptation.6 Apply your knowledge from this chapter to construct a dichotomous key for the five

different plant samples you collected in Activity 2.3.4. Remember to only include one variable at each step, such as:• has flowers or seed pods OR does not have flowers or seed pods• is a wood plant OR is a soft, fleshy plant• has long, needle-like leaves OR does not have long, needle-like leaves.

7 Evaluate the advantages of vascular plants over non-vascular plants.

Research8 Pollen from anthophytes can often be used for identification purposes. Observe

some pictures of pollens from plants and compare them. Make a dichotomous key to separate them.

9 Tree rings can often be used to determine the ages of the plants. Investigate:a what a scientist who studies tree rings is calledb how tree rings formc what can be learnt from studying tree rings.

Figure 2.54 A magnified view of a clump of Archaean organisms.

Figure 2.53 Biologists collecting Archaea samples in the hot springs of the Obsidian Pool in the Yellowstone National Park, United States.

Figure 2.55 The Three-Domain system of classification as proposed by Carl Woese.

THE CHANGING FACE OF CLASSIFICATIONScientists are still testing and modifying the Linnaean classification system after 250 years. The development of microscopes led to the discovery of single-celled organisms (bacteria). This led to the number of kingdoms increasing from three (plants, animals and minerals) to the current five (Plantae, Animalia, Fungi, Protista and Monera).

In the 1970s a group of organisms previously thought to be bacteria was discovered to be something else: single-celled organisms that could live in extreme conditions, such as very salty or hot waters. This led to the suggestion that a sixth kingdom, Archaea (ancient bacteria), was needed. Scientists are currently testing this idea and comparing it to a whole new system that comes before kingdoms.

The Three-Domain system was first suggested in 1990 and inserts a new level of classification before kingdom. This system suggests one domain, Eukarya, for the plants, animals, protists and fungi. The single-celled, prokaryotic organisms in the Monera kingdom would then be split into two domains according to their DNA.

The comparison of DNA may cause even greater changes to the classification system in the future. Species that were previously thought to be related because they looked similar have now been found to have very different genetic material. That is the very nature of science—to change and develop as new evidence becomes available. This is why scientists collaborate and share ideas, to make sure we have the best possible explanation for every scientific discovery.

The Internet allows more sophisticated ways of organising, storing and communicating scientific information. Massive online databases are possible, complete with photographs and video footage of organisms. Links to related information can also be included and many scientists are using the Internet to confirm their identifications.


SYLLABUS LINKS

Outcomes SC4-14LW relates the structure and function of

living things to their classification, survival and

reproduction

SC4-15LW explains how new biological evidence

changes people’s understanding of the world

Knowledge and understanding LW1 There are differences within and between

groups of organisms; classification helps organise

this diversity (ACSSU111).

Students:

a identify reasons for classifying living things

d identify some examples of groups of

microorganisms

e outline the structural features used to group

living things, including plants, animals, fungi

and bacteria

• classify,usingahierarchicalsystem,arange

of selected plants and animals to species level

(additional)


Activity 2.3.4: Identifying plantsSC4-4WS Questioning and predicting

SC4-6WS Conducting investigations

SC4-7WS Processing and analysing data and

information

SC4-9WS Communicating

Learning across the curriculum • Critical and creative thinking

• Information and communication technology

capability

• Literacy

• Personal and social capability

Starter activity: The changing face of classificationSome of the concepts in this section may need to be

explained before starting. Ask students if they have

heard of DNA, what is it and how is it used. Most

will have heard about the use of DNA in forensics,

for identification of disaster victims, and possibly in

paternity cases. Explain that it is an important substance

because it is passed on or inherited. It is an example of

genetic material.

Teaching strategyThe concept of rearranging and changing the

classification hierarchy may be daunting for

some students. Structure groups so that less

able students are placed with more capable,

supportive students.

Activity: Investigative processScience can be considered as a series of

investigative processes: questioning and

predicting, planning, conducting, processing,

analysing and communicating investigations.

Along the way, problem-solving is needed

to ensure the whole process is valid. The key

idea is that science is based on evidence,

and the ideas are adjusted appropriately as

the evidence changes or new information is

found.

Place the six headings of the investigative

process around the room and ask

students to work in structured groups (see

Differentiation). Each group will write the

changes to science from the text on sticky

notes and place them in the science process

where they belong.



archaea

bacteria

eukarya

ALL LIFE




methanogens

halophiles

thermoacidophiles

protista

fungi

plantae

animalia

KINGDOM







answer.


















DifferentiationFor less able students:• Theymaystrugglewiththeconceptsand

language, so structured group work where

they are teamed with more able students

might help.

Extension activity‘Extreme communities’, the Making

Connections section at the end of the chapter,

is a case study in changes in science and can

be used as an extension task.

ANSWERS

ACTIVITY 2.3.4: Identifying plantsOrganise an excursion to a local park or reserve, or even within the school grounds, to observe and collect plants. Plants are often described based on their growth habit (grasses and herbs, shrubs, trees, mallees) or growth cycles (annuals or perennials).

QUESTIONS 2.3.5 Classifying plants1 Xylem are tubes that carry water and

dissolved nutrients up from the roots of the plant to every cell. Phloem are tubes that

carry dissolved sugars that the plant makes through photosynthesis to the cells where it is needed.

2 Anthophytes are easily identified by the fact they produce flowers as a means of reproduction.

3 Neither mosses nor liverworts are likely to be found in the desert because they cannot efficiently absorb water from the soil—they do not have true roots. They are found in very damp and shady places or close to the water table.

4 Student responses will vary depending on the samples collected.

5 Winged seeds can travel some distance from the parent plant. When the seed germinates, it has more chance of getting the water and light it needs without competing with the larger parent plant. As plants do not move around, the winged seeds give the plant the opportunity to disperse. Plants cannot adapt by changing location if conditions change, but some of the species are more likely to survive if they have a wide distribution.

6 Student responses will vary depending on the samples collected, but emphasis should be on clear, logical divisions at each branch.

7 An advantage of having veins is that solutions and water can be easily transported. We could not be the size we are if we did not have arteries and veins to move materials around. As plants moved onto land, they needed ways of absorbing and transporting water and minerals. The veins let them do this, so they can grow in drier places and grow to a much larger size.


9 a A scientist who studies tree rings is called a dendrochronologist.

b As trees grow, they form new layers of bark or vascular cambium. The rings are the remains of vascular tissue, usually phloem, which tend to be on the outer edge of the vascular cambium.

c Trees usually grow a new layer of vascular cambium every year, so the number of rings in a tree is a good estimate of the age of the tree. The width of the rings is also an indication of the climate of that year. The wider the ring, the more favourable the conditions and the more the tree grew that year.

> Weblink: Background on changes in classification


plants > Editable risk assessment of the activity written


RESOURCES



Remember

1 Fill in the gaps, using the words in the Word Bank below: Classification of organisms is continually changing as new __________ is discovered. New __________ allows more of the planet to be explored and new __________ are being found. Advances in __________ research means that DNA is now being used to __________ how closely related species are. This new information sometimes requires a change in the way we __________ those organisms. Through the Internet and easily accessible photographic and video technology, __________ information can be shared more quickly and more frequently so __________ around the world can work together.

2 A ‘three-kingdom’ system became five and then six kingdoms.a Identify the names of these kingdoms.b Do you agree with the changes? Explain.

3 Describe how an understanding of DNA and genetics has changed classification.4 Describe a holotype specimen.

apply5 Explain why you think scientists might choose a single organism to represent its

species, instead of trying to find a description that fits every single organism in the species.

6 Examine the problems a paper system for classification would encounter. How is this being addressed today?

7 Use the Internet to research and describe an example of an organism where classification has changed as a result of scientific developments such as genetics.

8 Research the definitions of halophile, thermoacidophile and methanogen.9 Research the terms cyanobacteria, gram-negative and gram-positive. What are the

key features that are used to classify these different types of bacteria?

Create10 Using the information in this chapter and a large piece of paper, construct a

branching diagram showing the five Kingdoms and the major groups or phyla within each Kingdom. Add pictures to show examples of organisms within each group. Include brief descriptions of the key characteristics that are used to classify each group.

QUESTIONS 2.3.6: THE CHANGING FACE OF CLASSIFICATION

Figure 2.56 Holotype specimens such as this one are held in museums.

2.3CHECKPOINT

Remember and understand1 Identify the difference between

vertebrates and invertebrates. Write a definition for each. [2 marks]

2 Recall the five main classes of vertebrate and give an example of each. [5 marks]

3 Recall who first developed the naming system used by scientists today. [1 mark]

4 Identify and list at least six phyla of invertebrates and give an example of each. [6 marks]

5 Explain the difference between an endoskeleton and an exoskeleton. [1 mark]

6 How are placental mammals differentiated from monotremes and marsupials? [1 mark]

7 Outline why scientists need to classify living things. [1 mark]

apply8 Copy and complete the table below.

[4 marks]

animal vertebrate/invertebrate Class

Octopus

Spider

Human

Crab

Elephant

Frog

Lizard

Snail

analyse and evaluate9 Convert the tabular dichotomous

key (Table 2.5) to a circular key for invertebrates. [2 marks]

CLASSIFICATION TODAY10 Construct a Venn diagram to show the

similarities and differences between birds, reptiles and amphibians. [2 marks]

11 Discuss why it is important that scientists keep reviewing and evaluating the systems they use for classifying and naming living organisms, and modifying them if necessary. What problems might arise if scientists were not able to modify the systems? [2 marks]

Critical and creative thinking12 Using a digital camera, take

photographs of living things around your house—from very big to very small. Construct a multimedia presentation of your living things. Use a separate slide for each organism. On each slide include:

• the photograph

• the common name and scientific name (if you can find it) or major group to which it belongs

• three or more interesting facts. [5 marks]

Making connections13 Write a paragraph about how our

knowledge of life on the Earth has changed over time to bring us to the understanding we have today. Include some specific examples of understandings that have changed. [3 marks]

TOTal MaRKS [ /35]

Classify Evidence Genetic Species Identify Technology Accurate ScientistsW

ORD

BAN

K

Museums and herbaria currently hold most ‘holotype’ specimens, the organism(s) used when the description for classification was decided. These specimens are chosen because they represent the majority of organisms of the same type. Museums are likely to continue to do this, but most will need to put their data online in the future.


ANSWERS

QUESTIONS 2.3.6 The changing face of classification1 evidence; technology; species; genetic; identify;

classify; accurate; scientists

2 a The names of the original three kingdoms were plants, animals and minerals. The five-kingdom system consists of plants, animals, fungi, monerans and protists. The Three-Domain system includes Eukarya (plants, animals, fungi and protists) and two prokaryotic groups: Archaea and Bacteria.

b The change to five kingdoms was necessary because of scientific advances: greater detail could now be observed and further information found. (Students are likely to have different answers based on whether they actually agree with the changes or not.)

3 The understanding of genetics changed the classification system: species that were originally considered to be related because they looked similar are actually quite different based on the genetic material each one contains.

4 A holotype specimen is the original specimen of an organism from which the description for classification was decided. These are housed in museums.

5 Scientists choose a single organism to represent the species instead of trying to find a description that fits every single individual in the species because there is variation within a species. For example, every human or dog looks different even though they are still part of the same species.

6 A paper system for classification can be very large and hard to sort through. Today, the Internet and online databases allow more sophisticated ways to store, organise and communicate this information.

7 Student responses will vary depending on the species they research.

8 Halophile – extremophile organisms that can survive in conditions of extremely high salt concentrations; Thermoacidophile – extremophile organisms that can survive in conditions of extremely high temperatures and acidity; Methanogen – extremophile organisms that produce methane as a by-product of their metabolic reactions.

9 Cyanobacteria are also called blue-green algae because they are similar in structure to chloroplasts. Gram staining is process of disguising different bacteria based on whether or not their cell walls are stained by crystal violet dye. Gram-positive bacteria will stain with crystal violet dye, whereas gram-negative bacteria have impenetrable cell walls that do not stain with crystal violet dye.

10 Dichotomous keys will vary slightly but should involve the following key terms: kingdom, phylum, class, order, family, genus, species, Animalia, Plantae, Fungi, Monera, Protista, mushrooms, moulds, yeasts, bacilli, cocci, spirilla, mono, diplo, strepto, staphylo, vertebrates, invertebrates, Mammalia, Aves, Reptilia, Amphibia, Pisces, monotremes,

marsupials, placental, arthropods, molluscs, poriferans, nematodes, annelids, platyhelminthes, cnidarians, echinoderms, bryophytes, pteridophytes, coniferophytes, anthophytes.

CHECKPOINT 2.3 Classification today1 Vertebrates have an endoskeleton.

Vertebrates are the group of animals with a backbone and a nerve cord that runs through the backbone. At some stage of their development they have pharyngeal slits and a notochord. Invertebrates have an exoskeleton or no skeleton. Invertebrates are the groups of animals that do not possess a backbone.

2 The five main classes of vertebrates are: Mammalia (e.g. human), Reptilia (e.g. crocodile), Amphibia (e.g. golden bell frog), Aves (e.g. kookaburra), Pisces (e.g. Murray cod).

3 Carolus Linnaeus invented the naming system that is still used today to name living things.

4 Six phyla of invertebrates are poriferans (e.g. sea sponges), cnidarians (e.g. jellyfish, corals, anemones), molluscs (e.g. snails, shell-covered aquatic animals, octopus), nematodes/annelids (worms; e.g. leeches, tapeworms, flatworms), echinoderms (e.g.



Remember














2.3CHECKPOINT










[4 marks]


Octopus

Spider

Human

Crab

Elephant

Frog

Lizard

Snail








• the photograph





TOTal MaRKS [ /35]


ORD

BAN

K



sea stars, sea urchins, sea cucumbers) and arthropods (e.g. spiders, insects).

5 An endoskeleton consists of a system of bones or cartilage that is internal. The muscles that attach to the bones to bring about movement are visible externally. An exoskeleton is a system of hard, rigid structures that are external to the connecting muscles, which operate from within the organism. The exoskeleton and its joints are visible externally.

6 A placental mammal looks like a smaller version of the adult when it is born. Marsupials are furless, blind and approximately 1 cm when born and travel

from the birth canal to the pouch where they attach to a nipple, then feed and grow. Monotremes hatch in an undeveloped state from an egg. They develop in a burrow or pouch and suckle milk from a patch on the mother’s underbelly.

7 Scientists need to classify living things to make sense of all the organisms studied, and identify a specific species in a simple and practical manner. Every species can be given a unique name, as opposed to common names that are often neither consistent nor unique.

8

Animal Vertebrate/invertebrate

Class

Octopus Invertebrate Mollusc

Spider Invertebrate Arachnid

Human Vertebrate Mammal

Crab Invertebrate Crustacean

Elephant Vertebrate Mammal

Frog Vertebrate Amphibian

Lizard Vertebrate Reptile

Snail Invertebrate Mollusc

9 See appendix page 105.


11 It is critical for scientists to keep reviewing, evaluating and modifying the systems they use for classifying and naming living organisms because new information may cause a change in the classification of a species. With the knowledge associated with genetics, we now know some species are in fact distinct and not closely related. Problems that may arise should this modification not be possible include incorrect data, misidentification of species, inability to classify some species, and new species would not be known.

12 Students responses will vary depending on the selected organisms.

13 Students responses will vary, however, students should mention such things as:

• TheknowledgeoflifeontheEarthhaschangeddramatically because of the changes and advances in technology. We can now access more environments and understand more about the structures and function of organisms, the make-up of their genetic material, and other biochemistry.

• Oneexampleisthediscoveryofthedeepunderseacommunities near volcanic vents. A vast new array of organisms has been revealed near these vents, and scientists have learned more information about ways of obtaining nutrition from compounds such as hydrogen sulfide. Technologies for exploration of these depths, as well as sophisticated microscopes, have allowed these discoveries.


STUDENT OBOOK LINKSWeblink: Mythbusters – Daddy longlegs minimyth

> A Mythbusters clip that demonstrates scientific questioning and the gathering of new information that may change classification

Checkpoint Worksheet: Support 2.3

> Digitally assignable worksheet designed to support struggling students to help bring them up to the expected level

Checkpoint Worksheet: Consolidate 2.3

RESOURCES



CHAPTER REVIEW2

The purpose of classification2 Identify three reasons why classifying

living things is important. [3 marks]

3 Outline one technological advance that has changed the classification of living things. [1 mark]

Classifying based on structural similarities and differences4 Explain how the water-holding frog

meets the eight criteria of living things. [3 marks]

5 Imagine you are one animal from a phylum of invertebrates (such as molluscs, arthropods, annelids, nematodes, echinoderms, etc.). Write a diary entry explaining the key events in your day, explaining how

you demonstrate at least four of the characteristics of living things. [4 marks]

6 Research why the Three-Domain system of classification was suggested. (Hint: what do organisms within each domain have in common, and what makes them different from each other?) [2 marks]

Use keys to identify plants and animals7 Construct a jellyfish diagram to

summarise the classification of the four main phyla of plants. Which group is best adapted to living in a range of Australian environments? Explain your answer. [3 marks]

CHAPTER REVIEW

21 Fill in the gaps, using the words in the Word Bank below:

________________ is the process of grouping organisms based on similarities and differences in ________________ features. Classification helps ensure there are no errors in communication between scientists ________________ the same organism.

The features used to classify organism are also ________________ which increase the likelihood of survival and reproduction. Australia has three different types of mammals; placentals, ________________ and monotremes, which are classified according to the way they ________________.

The ________________ Classification System classifies all life into increasingly specific levels from Kingdom, ________________, Class, ________________, Family, ________________ to Species. Each level contains less organisms than the one before it.

Keys are used to identify organisms that have already been classified. ________________ keys work as a series of steps, with only two options at each step, while ________________ keys give more choices per step.

There are five different kingdoms: ________________, Plantae, Fungi, ________________ and Protista. Microorganisms can be found in the kingdoms ________________, Monera and Protista. Cellular structures are used to classify microorganisms. For example, organisms from Monera do not store their DNA in a nucleus and plants have a ________________ while animals do not.

8 Use the following tabular dichotomous key to identify the animals shown in Figure 2.57. [2 marks]

1Gills present Go to 2

Blow hole present Go to 3

2Scales present Tuna

Rough skin Shark

3Less than 3 m long Dolphin

Longer than 3 m Go to 4

4Teeth present Toothed whale

No teeth present Baleen whale

Identify groups of microorganisms9 Draw a table to help identify the

different names used to identify the different shapes of bacteria. [2 marks]

10 Identify the names of the five kingdoms of classification of living things. [2 marks]

11 Imagine you were van Leeuwenhoek, seeing bacteria for the first time. He asked the question ‘If these tiny creatures live in water, I wonder if they live inside us?’ Propose three other questions he could have asked and then investigated. [3 marks]

12 Suggest a reason why bacteria are classified by their appearance and not, say for example, by how they produce young. [1 mark]

Outline features used to group plants, animals, fungi and bacteria13 For each of the five main classes of

vertebrates, explain the advantages and disadvantages of their different body coverings, i.e. moist skin (amphibians), scales (fish and reptiles), feathers (birds), hair and fur (mammals). [4 marks]

14 Construct a table to summarise the key features that help to classify and identify plants, animals, fungi and bacteria. [2 marks]

Explain australian plant and animal adaptations15 Identify one ectothermic and one

endothermic Australian animal and describe one adaptation of each animal. [2 marks]

16 Use information in this chapter to construct a comprehensive table that includes the physical and behavioural adaptations of the echidna and how they help it survive and reproduce successfully. Which of these features (and any others) are useful for classifying the echidna? [3 marks]

17 Design a plant that is well suited to living in an area that is exposed to frequent droughts and bushfires. Explain how its adaptations help it survive in its environment. [3 marks]

18 Evaluate whether or not the Wollemi pine is well adapted to Australian conditions. Explain your answer. [2 marks]

Figure 2.57 Identify these animals using the tabular dichotomous key.

Animalia

Adaptations

Circular

Classification

Cell wall Describing

Dichotomous

Fungi

Genus

Marsupials

Monera

Linnaean

Order

Phylum

Reproduce

StructuralWOR

D BA

NK

a

b

c

d e

9594 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4 2 ChaPTER REvIEW

ANSWERS

CHAPTER REVIEW 1 classification; structural; describing;

adaptations; marsupials; reproduce; Linnaean; phylum; order; genus; dichotomous; circular; Animalia; Monera; Fungi; cell wall

2 Classifying living things makes it easier to communicate about living things. Classification means communication is more accurate, there is universal understanding and agreement about the species being referred to, and it helps biologists to understand the relationships of living things.

3 Technological advances that have changed classification include the development of the microscope and genetic research.

4 The water-holding frog meets the eight criteria of living things as it moves (e.g. digging a burrow), reproduces by laying eggs that hatch into tadpoles (as do most amphibians), grows (from being a tadpole into the adult frog), takes in food when not cocooned, exchanges gases by breathing, takes in water (hence the need for a cocoon in dry times), responds (by burrowing when conditions make it necessary), and produces waste products.

5 Student responses will vary depending on which organism they choose, but responses should emphasise at least four out of the eight key characteristics of all living things (MR N GREWW).

6 The discovery of ancient bacteria called the five kingdoms into question. The Three-Domain system was suggested to classify bacteria into three domains; Archaea (ancient bacteria and extremophiles), Bacteria (all other prokaryotic organisms) and Eukarya (all eukaryotic organisms).

7 The jellyfish diagram would identify:

• mossesandliverworts–noveinsortrue roots or leaves; small; needs water for fertilisation; can produce spores

• ferns–vasculartissue;atruerootandstem system but still needs water for fertilisation; produces spores

SYLLABUS LINKS












capability• Literacy



CHAPTER REVIEW2

The purpose of classification2 Identify three reasons why classifying

living things is important. [3 marks]

3 Outline one technological advance that has changed the classification of living things. [1 mark]

Classifying based on structural similarities and differences4 Explain how the water-holding frog

meets the eight criteria of living things. [3 marks]

5 Imagine you are one animal from a phylum of invertebrates (such as molluscs, arthropods, annelids, nematodes, echinoderms, etc.). Write a diary entry explaining the key events in your day, explaining how

you demonstrate at least four of the characteristics of living things. [4 marks]

6 Research why the Three-Domain system of classification was suggested. (Hint: what do organisms within each domain have in common, and what makes them different from each other?) [2 marks]

Use keys to identify plants and animals7 Construct a jellyfish diagram to

summarise the classification of the four main phyla of plants. Which group is best adapted to living in a range of Australian environments? Explain your answer. [3 marks]

CHAPTER REVIEW

21 Fill in the gaps, using the words in the Word Bank below:

________________ is the process of grouping organisms based on similarities and differences in ________________ features. Classification helps ensure there are no errors in communication between scientists ________________ the same organism.

The features used to classify organism are also ________________ which increase the likelihood of survival and reproduction. Australia has three different types of mammals; placentals, ________________ and monotremes, which are classified according to the way they ________________.

The ________________ Classification System classifies all life into increasingly specific levels from Kingdom, ________________, Class, ________________, Family, ________________ to Species. Each level contains less organisms than the one before it.

Keys are used to identify organisms that have already been classified. ________________ keys work as a series of steps, with only two options at each step, while ________________ keys give more choices per step.

There are five different kingdoms: ________________, Plantae, Fungi, ________________ and Protista. Microorganisms can be found in the kingdoms ________________, Monera and Protista. Cellular structures are used to classify microorganisms. For example, organisms from Monera do not store their DNA in a nucleus and plants have a ________________ while animals do not.

8 Use the following tabular dichotomous key to identify the animals shown in Figure 2.57. [2 marks]

1Gills present Go to 2

Blow hole present Go to 3

2Scales present Tuna

Rough skin Shark

3Less than 3 m long Dolphin

Longer than 3 m Go to 4

4Teeth present Toothed whale

No teeth present Baleen whale

Identify groups of microorganisms9 Draw a table to help identify the

different names used to identify the different shapes of bacteria. [2 marks]

10 Identify the names of the five kingdoms of classification of living things. [2 marks]

11 Imagine you were van Leeuwenhoek, seeing bacteria for the first time. He asked the question ‘If these tiny creatures live in water, I wonder if they live inside us?’ Propose three other questions he could have asked and then investigated. [3 marks]

12 Suggest a reason why bacteria are classified by their appearance and not, say for example, by how they produce young. [1 mark]

Outline features used to group plants, animals, fungi and bacteria13 For each of the five main classes of

vertebrates, explain the advantages and disadvantages of their different body coverings, i.e. moist skin (amphibians), scales (fish and reptiles), feathers (birds), hair and fur (mammals). [4 marks]

14 Construct a table to summarise the key features that help to classify and identify plants, animals, fungi and bacteria. [2 marks]

Explain australian plant and animal adaptations15 Identify one ectothermic and one

endothermic Australian animal and describe one adaptation of each animal. [2 marks]

16 Use information in this chapter to construct a comprehensive table that includes the physical and behavioural adaptations of the echidna and how they help it survive and reproduce successfully. Which of these features (and any others) are useful for classifying the echidna? [3 marks]

17 Design a plant that is well suited to living in an area that is exposed to frequent droughts and bushfires. Explain how its adaptations help it survive in its environment. [3 marks]

18 Evaluate whether or not the Wollemi pine is well adapted to Australian conditions. Explain your answer. [2 marks]

Figure 2.57 Identify these animals using the tabular dichotomous key.

Animalia

Adaptations

Circular

Classification

Cell wall Describing

Dichotomous

Fungi

Genus

Marsupials

Monera

Linnaean

Order

Phylum

Reproduce

StructuralWOR

D BA

NK

a

b

c

d e

9594 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4 2 ChaPTER REvIEW

• conifers(gymnosperms)–trulyvascular with roots, stems and leaves, naked seeds (not in an ovary), usually wind pollinates and disperses seeds

• floweringplants(angiosperms)–trulyvascular with roots, stems and leaves; seeds in an ovary in a flower that develops into a fruit; pollinated in a wide variety of ways

The flowering plants are best adapted to Australian conditions because their seeds are well protected, they efficiently absorb and conduct water and food, and they are pollinated in a variety of ways.

8 a – shark; b – tuna; c – dolphin; d – baleen whale; e – toothed whale

9 See appendix page 105.10 The five kingdoms are Animalia, Plantae,

Fungi, Monera and Protista.11 Student responses will vary but may

include questions such as: How do these tiny creatures get food? How do these tiny creatures reproduce? What eats these tiny creatures?

12 All bacteria reproduce in the same way, by binary fission, so this is not an effective way to distinguish between different species.

13 Amphibians have moist skin and can absorb materials from surroundings, but dehydrate easily. Scales on fish act as protection, but they may not be so flexible. Scales are also are sensitive so fish can detect their surroundings. Scales on reptiles prevent them from dehydrating, but they still lose body heat. Feathers insulate, but need cleaning. Hair insulates and senses environment, but can hold parasites such as lice.

14 Student responses will vary, but should include some of the features listed.

Plants Animals Fungi Bacteria

Cell wall ✓ ✗ ✓ ✓

True nucleus ✓ ✓ ✓ ✗

Photosynthesis ✓ ✗ ✗ some

Sessile (attached to surface)

✓ few ✓ ✗

Multicellular ✓ ✓ some ✗

15 Student responses will vary but may include: ectothermic – water-holding frog stores water to survive droughts; endothermic – echidna has strong claws that are used for digging.

16 Student responses will vary, but should include some of the features listed. All of the physical adaptations are useful for classifying the echidna. The behavioural adaptations are questionable because they may vary from individual to individual.

Physical adaptations of echidna

Behavioural adaptations of echidna

Long sharp spines Sunbakes by stretching out in the sun

Long snout like a beak, sensitive to touch and smell

Elusive and unpredictable

Pouch for protecting young Forages while incubating eggs, caring for young

Strong claws Digs for prey

Long sticky tongue Coils into a ball for defence

Eggs

17 The plant would have thick, hard bark (insulation from the heat of fire) and store its seeds in woody cases (protection from fire). The leaves would be waxy and hang vertically (preventing dehydration). The root system would be very deep and extensive (collecting whatever water is available). It would have a thick, bulbous trunk (to store water).

18 The Wollemi pine is not well adapted to the Australian environment because it has only survived naturally in one small, sheltered area.



CHAPTER REVIEW219 Ultraviolet light not only causes

sunburn but also promotes the growth of cancer cells. Identify and list some adaptations that might help living organisms survive in a changed environment of increased ultraviolet light. [2 marks]

Constructing simple identification keys (additional)20 Construct a ‘What am I?’ list of clues

to a phylum or other major group of organisms. See how many clues your classmates need before they guess the name of the group. [2 marks]

21 Using the link provided by your teacher (or in your obook), view the slide show, made in Canada, of 35 slides of living things. Construct your own version to emphasise the classification and diversity of Australian species. [5 marks]

Use the linnaean classification system22 Research the Wollemi pine. What is its

full scientific name (from kingdom to species)? To what group of plants does it belongs (vascular or non-vascular)? How does it reproduce? [4 marks]

TOTal MaRKS [ /55]

RESEARCH

Choose one of the following topics to present a report in a format of your own choice. Some ideas have been included to get you started. Your report must include a key of some description (you have seen many in this chapter).

newspaper articleWrite a newspaper article about how life on the Earth is organised. It needs to be about two pages long (no more than 500 words) and you should explain how living things are classified for an audience that is not familiar with science. Make a list of the living things whose photographs you would like to use to illustrate the article. Try to find their scientific names as well as their common names. Your newspaper article must contain a key of some description.

Trip to the KimberleyYou have just returned from a trip to a remote mountain area of the Kimberley, in Western Australia. While there, you took your portable microscope and examined water from a previously unknown lake. To your surprise you found some new organisms in the water that looked a bit like bacteria. They were single-celled and either square or oval; some were hairy (had hairs either on the end of the cell or along the edge of the whole cell).

Me1 What new graphic organisers have you

learned to use?2 How could dichotomous keys be useful

in other subjects? Give examples.3 What were the most difficult aspects

of this topic?

My world4 What was the most surprising

organism you discovered?5 What else would you like to find out

about classification?6 What else would you like to find out

about organisms?7 Why is it important to organise life on

the Earth?

REFLECT

My future8 What Australian animals are unique in

the world? How are we going to protect them in the future?

KEy WORDSadaptationsamoebaArchaeaautotrophbacteriabinomial namebiodiversitybotanistbranched keycellcell wallChordataclassification

deaddichotomous keyDNAectothermendoskeletonendothermeukaryoteexoskeletongenusheterotrophinvertebratekeykingdom

livingmarsupialmicrobiologistmicroorganismmonotrememulticellularmycologistnon-livingnon-vascularnucleusorderorganismphloem

phylumplacentalplanktonprokaryotespeciestaxonomistunicellularvascularvertebratexylemzoologist

1 Draw six different versions of these organisms.

2 Create a dichotomous key for these six new organisms so that you can describe them to other scientists.

3 Name each of the groups at the bottom of your key (you might like to name some of them after yourself).

4 Assuming they are a type of bacteria, to which kingdom will they belong?

Research on fascinating organismsChoose a fascinating organism to research from each kingdom. As you do your research, create a table using the following headings for each organism: ‘Habitat’, ‘Diet’, ‘Classification’ and ‘Special features’. Choose one of the graphic organisers used in this chapter to display the information about each one. Keep a list of the sources of your information.

2 CHAPTER REVIEW 9796 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4

ANSWERS

CHAPTER REVIEW 19 Adaptations that may protect from ultraviolet light

include dark skin, thicker fur, feathers or scales, becoming nocturnal or burrowing, and living in the water.

20 Student responses will vary, but should be similar to the following example.

For class Amphibia: I like change. I spend some of my life in water and some on land. I have moist skin. My body temperature is the same as my surroundings. I lay eggs in water. I do not look after my young.

21 Student responses will vary depending on organisms chosen.

22 The scientific name for the Wollemi pine is Wollemia nobilis. The full classification is: Plantae, Tracheophyta, Coniferopsida, Coniferales, Araucariaceae, Wollemia nobilis. It is a vascular plant and it produces male and female cones on the same tree. It is classified, along with the other ‘naked’ seed plants, as a gymnosperm or conifer.

ResearchResearch tasks are an effective way of assessing learning and other capabilities, and can be used effectively as an assessment task in lieu of, or alongside, other methods of assessment. The three topics presented give students a choice based on their interests, and some control over their learning. Students could complete the research after planning the project, or be allowed to complete the research if their planning is sufficient.

ReflectReflection activities help students gain insight into their own learning. They may be useful for assessing students’ personal learning journeys either through discussion or in a reflection journal, which is updated throughout the year.

Key wordsA glossary of key words helps remind students of relevant scientific language and concepts.



CHAPTER REVIEW219 Ultraviolet light not only causes

sunburn but also promotes the growth of cancer cells. Identify and list some adaptations that might help living organisms survive in a changed environment of increased ultraviolet light. [2 marks]

Constructing simple identification keys (additional)20 Construct a ‘What am I?’ list of clues

to a phylum or other major group of organisms. See how many clues your classmates need before they guess the name of the group. [2 marks]

21 Using the link provided by your teacher (or in your obook), view the slide show, made in Canada, of 35 slides of living things. Construct your own version to emphasise the classification and diversity of Australian species. [5 marks]

Use the linnaean classification system22 Research the Wollemi pine. What is its

full scientific name (from kingdom to species)? To what group of plants does it belongs (vascular or non-vascular)? How does it reproduce? [4 marks]

TOTal MaRKS [ /55]

RESEARCH

Choose one of the following topics to present a report in a format of your own choice. Some ideas have been included to get you started. Your report must include a key of some description (you have seen many in this chapter).

newspaper articleWrite a newspaper article about how life on the Earth is organised. It needs to be about two pages long (no more than 500 words) and you should explain how living things are classified for an audience that is not familiar with science. Make a list of the living things whose photographs you would like to use to illustrate the article. Try to find their scientific names as well as their common names. Your newspaper article must contain a key of some description.

Trip to the KimberleyYou have just returned from a trip to a remote mountain area of the Kimberley, in Western Australia. While there, you took your portable microscope and examined water from a previously unknown lake. To your surprise you found some new organisms in the water that looked a bit like bacteria. They were single-celled and either square or oval; some were hairy (had hairs either on the end of the cell or along the edge of the whole cell).

Me1 What new graphic organisers have you

learned to use?2 How could dichotomous keys be useful

in other subjects? Give examples.3 What were the most difficult aspects

of this topic?

My world4 What was the most surprising

organism you discovered?5 What else would you like to find out

about classification?6 What else would you like to find out

about organisms?7 Why is it important to organise life on

the Earth?

REFLECT

My future8 What Australian animals are unique in

the world? How are we going to protect them in the future?

KEy WORDSadaptationsamoebaArchaeaautotrophbacteriabinomial namebiodiversitybotanistbranched keycellcell wallChordataclassification

deaddichotomous keyDNAectothermendoskeletonendothermeukaryoteexoskeletongenusheterotrophinvertebratekeykingdom

livingmarsupialmicrobiologistmicroorganismmonotrememulticellularmycologistnon-livingnon-vascularnucleusorderorganismphloem

phylumplacentalplanktonprokaryotespeciestaxonomistunicellularvascularvertebratexylemzoologist

1 Draw six different versions of these organisms.

2 Create a dichotomous key for these six new organisms so that you can describe them to other scientists.

3 Name each of the groups at the bottom of your key (you might like to name some of them after yourself).

4 Assuming they are a type of bacteria, to which kingdom will they belong?

Research on fascinating organismsChoose a fascinating organism to research from each kingdom. As you do your research, create a table using the following headings for each organism: ‘Habitat’, ‘Diet’, ‘Classification’ and ‘Special features’. Choose one of the graphic organisers used in this chapter to display the information about each one. Keep a list of the sources of your information.

2 CHAPTER REVIEW 9796 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4

STUDENT OBOOK EXTRAS

Flashcard Glossary: Classification > Interactive task where students can test their

knowledge of the key terms relevant to the chapter

WORKBOOK OBOOK EXTRAS > Workbook 2.10: Research adaptation and

habitats > Editable version of workbook activity, which can

be digitally assigned to students for homework > Workbook 2.11: Chapter Review – Classification > Editable version of workbook activity, which can


RESOURCES



2MAKING

CONNECTIONS

Extreme communitiesBlack smokersIn 1977, two scientists and a pilot crammed into an extreme submarine, ALVIN, and headed nearly 3000 metres under the sea, near the Galapagos Islands. They predicted that the chains of underwater volcanoes, called mid-ocean ridges, would have hot springs a lot like deep undersea versions of the hot springs of Yellowstone National Park. Until then, no deep-sea volcanic vents had ever been found.

The scientists found the first hot water deep-sea vent, just as they predicted, but they were surprised to also find diverse communities of living organisms. Hot water rich in minerals gushed out of the chimney-like vents and mixed with the cold ocean water, reacting to form dense clouds of tiny black minerals. These chimneys are called ‘black smokers’.

New researchThis discovery opened up a whole new area of research. Oceanographers had to develop new technologies to explore these deep-sea environments. Biologists discovered, classified and investigated a whole new range of microorganisms, invertebrates and vertebrates. Geologists studied the rock formations and composition of the minerals and vented water. So far, only 1% of the ocean floor has been mapped, so there is much more to learn. There is still more to understand about the impact of these vents on the chemistry of the whole ocean.

ExploitationDeep-sea vents are rich in valuable mineral ores. Mineral exploration companies are at work and mining operations similar to offshore oil and gas rigs have already been trialled.

DarknessThere is no natural sunlight in the deep-sea environment, and only a few places where there is the red glow from lava oozing out of cracks in the rocks.

PressureWe all experience the ‘popping’ of our ears with a change of pressure. This is nothing compared to the changes in pressure involved in travelling to the ocean depths. The pressure experienced is about 300 times the air pressure experienced at sea level. This would feel like having a mass of 300 kilograms resting on your fingernail.

TemperatureThe high-pressure environment increases the boiling point of the water. Superheated water at these depths can reach temperatures of 400ºC. In contrast, the water temperature away from the vent is 2ºC.

Apart from the darkness, pressure and temperature variations, there are other reasons why the waters here are not ideal for most life. These include high salinity and acidity. The water is about as acidic as vinegar.

CommunitiesThe basis of these deep-sea communities is the bacteria that feed off hydrogen sulfide or methane. These bacteria have been described as ‘extremophiles’ because they survive the extremes of these deep parts of the ocean. Amphipods and copepods feed off thick mats of bacteria. Snails, shrimp, mussels, clams, anemones, crabs, tube worms, eels and octopuses can also be found in this environment. Life down in the deep sea does not depend on the sun.

Some of the interesting animals that live at these depths include the Pompeii worm, Alvinella pompejana, which withstands temperatures up to 80ºC, and the scaly-foot gastropod, Crysomallon squamiferum, which has a reinforcing of iron and organic materials on its foot. Others are giant tube worms, Riftia pachyptila, which grow up to 2 metres in length but lack a mouth and digestive system.

The mysterious giant tube wormHow the giant tube worm obtained food greatly puzzled biologists until a graduate student, Colleen Cavanaugh, was observing a dissection of a giant tube worm and observed an organ, called a trophosome, being sliced up. This organ was the main internal organ and it was noted that it sometimes contained crystals of sulfur. The possible functions of this strange organ were being discussed. Cavanaugh jumped up to share her inspiration. She thought the tissues in the organ contain sulfur-eating bacteria that provide food for the tube worm. The tube worm extracts the sulfur substances from the water to keep the bacteria on the job. Research has since proved her inspiration to be correct.

1 Explain why plants don’t live in the communities around deep-sea vents.

2 How has the discovery of deep-sea vent communities changed our understanding of the diversity of living things?

3 Many of the animals found near deep-sea vents are blind. Explain why you think this might be.

4 Examine how the discovery of the deep-sea vent communities has changed the classification of living things.

5 Construct a paragraph arguing why ongoing research into deep-sea vents is worthwhile.

6 Science is often divided into the areas of biology, chemistry, physics and geology.a Explain why you think the two

scientists that went on the initial exploration in ALVIN were geologists.

b Why do you think that scientific research like the exploration of deep-sea vents depends on collaboration?

7 Write an advertisement for a scientist to join a team to explore the deep-sea hydrothermal vents.

8 Is advancement in science based on inspiration or perspiration? Use the example of the discovery of how the giant tube worm gets its nutrition to explain your answer.

9 Photosynthesis is the term given to organisms that use light to produce their nutrients and energy. The organisms found on deep sea ocean vents do not use light but instead use chemicals. Suggest an appropriate name to describe how these organisms obtain their nutrients and energy.

10 Design a dichotomous key to distinguish and identify five ‘black smoker’ species. For each species, identify one adaptation that helps it to survive in its environment.

Figure 2.58 A black smoker.

992 MAKING CONNECTIONS98 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4

SYLLABUS LINKS







Working scientifically SC4-4WS Questioning and predictingSC4-7WS Processing and analysing data and informationSC4-9WS Communicating


Teaching strategyHighlight the parallel with the information at the

beginning of the chapter. The description of the

discovery of whole new groups of organisms, including

bacteria, resulted from the invention of the microscope.

The discovery of more new groups of organisms resulted

from the technologies that allowed us to explore deep-

sea environments. Students could construct a mind

map that displays the relationships between science and

technology.

ANSWERS1 Plants don’t live in the deep-sea vent communities

because there is no sunlight, so they cannot make their own food.

2 As a result of the discovery of the deep-sea vents, we now understand that there is even greater diversity of living things than previously understood.

3 There is no sunlight at the deep-sea vents, so these areas are almost completely dark. Functional eyes would not be an advantage.

4 Additional organisms have been added to the existing classification, plus new groups have been added that are different from previously described species.

5 There are both practical and academic reasons why research should continue into deep-sea vent communities. The practical reasons include the continued discovery of a variety of new species with adaptations to the extreme conditions. These new species may prove to be useful as resources or for

helping to decontaminate polluted areas. The academic reasons are about increasing our understanding of organisms, their adaptations and their relationships in communities. While there may be no direct benefits to humans by increasing our understanding, it is important to respond to our curiosity. Our understanding may prove to be useful in unforeseen ways.

6 a The first two scientists who venturedinto deep-sea vents were geologists, because up until then people did not know that any life forms existed at these depths. Deep-sea vents are volcanic, so it would be logical that



2MAKING

CONNECTIONS

Extreme communitiesBlack smokersIn 1977, two scientists and a pilot crammed into an extreme submarine, ALVIN, and headed nearly 3000 metres under the sea, near the Galapagos Islands. They predicted that the chains of underwater volcanoes, called mid-ocean ridges, would have hot springs a lot like deep undersea versions of the hot springs of Yellowstone National Park. Until then, no deep-sea volcanic vents had ever been found.

The scientists found the first hot water deep-sea vent, just as they predicted, but they were surprised to also find diverse communities of living organisms. Hot water rich in minerals gushed out of the chimney-like vents and mixed with the cold ocean water, reacting to form dense clouds of tiny black minerals. These chimneys are called ‘black smokers’.

New researchThis discovery opened up a whole new area of research. Oceanographers had to develop new technologies to explore these deep-sea environments. Biologists discovered, classified and investigated a whole new range of microorganisms, invertebrates and vertebrates. Geologists studied the rock formations and composition of the minerals and vented water. So far, only 1% of the ocean floor has been mapped, so there is much more to learn. There is still more to understand about the impact of these vents on the chemistry of the whole ocean.

ExploitationDeep-sea vents are rich in valuable mineral ores. Mineral exploration companies are at work and mining operations similar to offshore oil and gas rigs have already been trialled.

DarknessThere is no natural sunlight in the deep-sea environment, and only a few places where there is the red glow from lava oozing out of cracks in the rocks.

PressureWe all experience the ‘popping’ of our ears with a change of pressure. This is nothing compared to the changes in pressure involved in travelling to the ocean depths. The pressure experienced is about 300 times the air pressure experienced at sea level. This would feel like having a mass of 300 kilograms resting on your fingernail.

TemperatureThe high-pressure environment increases the boiling point of the water. Superheated water at these depths can reach temperatures of 400ºC. In contrast, the water temperature away from the vent is 2ºC.

Apart from the darkness, pressure and temperature variations, there are other reasons why the waters here are not ideal for most life. These include high salinity and acidity. The water is about as acidic as vinegar.

CommunitiesThe basis of these deep-sea communities is the bacteria that feed off hydrogen sulfide or methane. These bacteria have been described as ‘extremophiles’ because they survive the extremes of these deep parts of the ocean. Amphipods and copepods feed off thick mats of bacteria. Snails, shrimp, mussels, clams, anemones, crabs, tube worms, eels and octopuses can also be found in this environment. Life down in the deep sea does not depend on the sun.

Some of the interesting animals that live at these depths include the Pompeii worm, Alvinella pompejana, which withstands temperatures up to 80ºC, and the scaly-foot gastropod, Crysomallon squamiferum, which has a reinforcing of iron and organic materials on its foot. Others are giant tube worms, Riftia pachyptila, which grow up to 2 metres in length but lack a mouth and digestive system.

The mysterious giant tube wormHow the giant tube worm obtained food greatly puzzled biologists until a graduate student, Colleen Cavanaugh, was observing a dissection of a giant tube worm and observed an organ, called a trophosome, being sliced up. This organ was the main internal organ and it was noted that it sometimes contained crystals of sulfur. The possible functions of this strange organ were being discussed. Cavanaugh jumped up to share her inspiration. She thought the tissues in the organ contain sulfur-eating bacteria that provide food for the tube worm. The tube worm extracts the sulfur substances from the water to keep the bacteria on the job. Research has since proved her inspiration to be correct.

1 Explain why plants don’t live in the communities around deep-sea vents.

2 How has the discovery of deep-sea vent communities changed our understanding of the diversity of living things?

3 Many of the animals found near deep-sea vents are blind. Explain why you think this might be.

4 Examine how the discovery of the deep-sea vent communities has changed the classification of living things.

5 Construct a paragraph arguing why ongoing research into deep-sea vents is worthwhile.

6 Science is often divided into the areas of biology, chemistry, physics and geology.a Explain why you think the two

scientists that went on the initial exploration in ALVIN were geologists.

b Why do you think that scientific research like the exploration of deep-sea vents depends on collaboration?

7 Write an advertisement for a scientist to join a team to explore the deep-sea hydrothermal vents.

8 Is advancement in science based on inspiration or perspiration? Use the example of the discovery of how the giant tube worm gets its nutrition to explain your answer.

9 Photosynthesis is the term given to organisms that use light to produce their nutrients and energy. The organisms found on deep sea ocean vents do not use light but instead use chemicals. Suggest an appropriate name to describe how these organisms obtain their nutrients and energy.

10 Design a dichotomous key to distinguish and identify five ‘black smoker’ species. For each species, identify one adaptation that helps it to survive in its environment.

Figure 2.58 A black smoker.

992 MAKING CONNECTIONS98 OXFORD INSIGHT SCIENCE 7 AUSTRALIAN CURRICULUM FOR NSW STAGE 4

geologists would be highly qualified to investigate them more productively.

b Collaboration is necessary because there is a need for a range of scientific disciplines to contribute their understanding of the organisms and their environment. Technicians, such as the pilots and engineers that design the equipment, would need to collaborate with scientists to ensure a safe and successful exploration.

7 Students responses will vary. Advertisement example: Qualified and experienced marine biologist required to explore undersea communities. Experience

in classification of bacteria, invertebrates or fish desirable. Ability to work in a team and in confined spaces essential.

8 The discovery of how the giant tube worm obtains its nutrition was a combination of both perspiration and inspiration. The student who suddenly saw the connection between the sulfur in the trophosome and the sulfur-eating bacteria used inspiration, but the hours of dissections and observations and data gathering (perspiration) were necessary before the inspiration to suggest an answer. After the inspirational suggestion came the hard work to test the idea.

9 Students responses will vary. Try to encourage the use of appropriate scientific terminology as seen in the scientific binomial names of organisms.

10 Student answers will vary, but should incorporate a clearly thought out key like the following:

1a Is a vertebrate Eel1b Is not a vertebrate Go to 22a Is microscopic Bacteria2b Is not microscopic Go to 33a Has exoskeleton Crab3b Has no exoskeleton Go to 44a Has a scaly foot Scaly foot gastropod4b Has no scaly foot Octopus



102 APPENDIX

QUESTIONS 2.1.2 CLASSIFICATION OF LIVING THINGS4 a

Eucalypt tree Water Paper Robot Leather belt Wombat Roast chicken Computer virus

Moves by itself ✓ ✗ ✗ ✓ ✗ ✓ ✗ ✗

Reproduces itself ✓ ✗ ✗ ✗ ✗ ✓ ✗ ✓

Requires nutrition ✓ ✗ ✗ ✗ ✗ ✓ ✗ ✗

Grows as it gets older ✓ ✗ ✗ ✗ ✗ ✓ ✗ ✗

Responds to changes in its environment ✓ ✓ ✗ ✓ ✗ ✓ ✗ ✓

Exchanges gas (e.g. oxygen) ✓ ✓ ✗ ✗ ✗ ✓ ✗ ✗

Produces wastes ✓ ✗ ✗ ✗ ✗ ✓ ✗ ✗

Requires water ✓ ✓ ✗ ✗ ✗ ✓ ✗ ✗

Living or non-living? L NL NL NL NL L NL NL

ACTIVITY 2.2.3 MAKING A TABULAR DICHOTOMOUS KEY

Page 712

1No feathers covering body Go to 2

Feathers covering body Charlie

2Hair all over body Go to 3

Hair covering parts of body Go to 5

3Long ears Bugs

Short ears Go to 4

4Long tail Maggie

Short tail Buddy

5Unable to walk Scott

Able to walk Go to 6

6Male Go to 7

Female Go to 8

7No facial hair Peter

Facial hair Richard

8Red hair Vanessa

Not red hair Stephanie

Page 62

DEEPER UNDERSTANDING THINKERS’ KEYSSome suggested answers are:• Reverselistingkey:Anon-livingthingcould

never move, feed, reproduce, grow, respond, exchange gases, produce wastes, require water, think, sense the world (sight, hearing, etc.).

• ‘Whatif’key: If living things did not exist there would not be much variation. The main features of the landscape would be the shape of the land: mountains, valleys, soils and weather effects. The Earth would be a very still and quiet place, except for volcanic activity and other geological, astronomical or climatic events.

• Questionkey:Whatisaunicellularorganism?What are bacteria? What is the opposite of ‘multicellular’?

• Constructionkey:Answerswillvarydepending on classroom resources.

• Combinationkey:Theneworganismwillvary depending on the student. Attributes of an animal cell are a cell membrane, flexibility and nucleus with genetic material. The attributes of a plant cell are a cell wall, rigidity and nucleus with genetic material.

• Disadvantageskey:Wemaynotidentifythespecies correctly due to lack of information. Confusion could occur; for example, it is often debated whether viruses are living or non-

living. To correct this, there could be an extra classification group, Archaea, as suggested recently, and update the classification as new information is discovered.

• Predictionkey:Invertebratesarelikelytobediscovered in the next 20 years. Students may like to be more specific than this.

• Alphabetkey:Studentsarelikelytoincludethings such as respiration, respond, nutrition, water, wastes, exchange gases and reproduce.

• Commonalitykey:Bothhaveamass/weight,take up space, are made of cells, require all the characteristics of living things, obey natural laws such as the law of gravity, and contain genetic material.


103APPENDIX OXFORD INSIGHT SCIENCE 7 TEACHER KIT

Page 63

QUESTIONS 2.1.3 ADAPTATIONS FOR SURVIVAL AND REPRODUCTION8.

TYPES OF ADAPTATIONS

Physical/structural Chemical Behavioural Other

Thick fur Produces milk Foraging at night Lays eggs

Strong claws Water storage under the skin Burrowing underground Heat-resistant seeds

Long snout Huddling together

Sharp spines Perching eggs on top of feet

Shiny waxy leaves

Epicormic buds

Page 775

Kingdom Animalia Plantae Fungi Monera ProtistaScientist who studies the organisms

Zoologist Botanist Mycologist Microbiologist Microbiologist

Page 959

Round Rod-shaped Spiral-shapedSingle Monococcus Monobacillus MonospirillusIn pairs Diplococcus Diplobacillus DiplospirillusIn chains Streptococcus Streptobacillus StreptospirillusIn clusters Staphylococcus Staphylobacillus Staphylospirillus


104 WORKBOOK ANSWERS

CHAPTER 2 CLASSIFICATION

ACTIVITY 2.1 LIVING AND NON-LIVING1 a M Movement: living things can move by themselves.

R Reproduce: living things make new individuals that look like themselves.N Nutrition: living things require nutrients to survive.G Grow: living things grow as they get older.R Respond: living things respond to stimuli around them.E Exchange: living things exchange gases with their environment.W Wastes: living things produce wastes.W Water: living things require water to survive.

b Student responses will vary.2 a cat = living

salt = non-livinga drop of water = non-livingbacteria = livingan ant = livinggrass = livingmould = livingcomputer = non-living

3 Answers will vary depending upon the student’s choice.

4 Answers will vary depending upon the student’s choice.

5 A cloud has many of the features of living things. Clouds reproduce, grow, respond, and exchange water with the atmosphere. But clouds do not need nutrition and have no waste.

6 Robots can move and respond, but they are not living things. Robots are not capable of growth, nutrition and reproduction, which are key features of living things.

7 Features of candles:

• Movement:theflameflickersbywaftingandflickering.• Reproduction:flamesreproducebysparksandmatches.• Nutrition:flamesconsumewaxastheyburn.• Growth:flamescangrowasmorewaxisavailable.Flamesarebigger

on bigger candles than on small candles.• Respond:flamesrespondtoblowingonthem,addingmoreoxygen,or

pouring water onto the candle top.• Exchange:flamesconsumeoxygengasandproducecarbondioxide

gas. These gases are exchanged with each other.• Waste:candleflamesproducecarbondioxide,sootandwatervapour

as products which they cannot use.• Water:flamesrespondbadlytowater.Flamesareextinguishedby

water.8 A flame has many of the features of living things, but it is not living.

Flames cannot reproduce on their own, and they do not use the wax as nutrition to grow a bigger flame but burn it all into waste.

ACTIVITY 2.2 SORTING INTO KINGDOMS1 Three examples are given:

Seaweed (kelp)a Moves by being pushed by the water it is living in.b Spores float away in the water.

c Obtains energy from the sun, nutrients from the sea water.d Each frond grows larger in size.e Has limited responses.f Obtains and releases gases into the water it lives in.g Excretes waste into the water it lives in.h Obtains water from its environment.

Sharka Moves by using muscles in its body.b Has eggs and live young, depending on the type.c Obtains nutrients from the food it eats.d Grows as its body increases in size.e Has senses to detect stimuli, and responds differently in different

situations.f Has gills to extract oxygen from the water, and to remove carbon

dioxide.g Excretes wastes through its gills, kidneys and rectum.h Obtains water with its food.

Toy robota Moves when it is wound up and energy stored in the spring inside it.b Cannot reproduce.c Does not obtain nutrients.d Does not grow.e Only has some limited responses when it is moving.f Does not exchange gases.g Does not produce wastes.h Does not obtain water.


ACTIVITY 2.3 USING KEYS1 A key that branches into two at each branch.

2 Branched key and tabular key.

3 A branched key is easier to use because it lets us visualise where a particular member of the group fits in with the rest.

4 There are five classes of vertebrates: fish, amphibians, reptiles, birds and mammals.

5 The significant features of the classes of vertebrates are:

• Fish: slimy scales on skin, breathe by gills, most lay eggs, live in water• Amphibian: wet moist skin with no scales or hair or fur, young breathe

by gills and adults breathe by lungs, lay eggs in water or moist places• Reptile: dry scaly skin, breathe by lungs, most lay eggs with soft shells• Birds: skin covered with feathers, breathe by lungs, lay eggs with hard

shells• Mammals: skin covered with fur or hair, breathe by lungs, most give

birth to live young, young are nourished on milk.


105WORKBOOK ANSWERS OXFORD INSIGHT SCIENCE 7 TEACHER KIT

Dichotomous key to classify vertebratesVetebrates

Wet slimy skin

Scales on skin

FISH

No scales or hair

AMPHIBIAN

BIRD

Has hair or fur

Feathers

MAMMAL

REPTILE

Does not have hair or fur

Scales

Dry skin

6 The three groups of mammals are:

• Marsupials: give birth to small embryo-like young, which then develop in a pouch, tightly attached to a nipple to obtain milk.

• Placentals: give birth to developed young, which have grown in a placenta (womb), the young feed on milk.

7 The alternative type of key is a tabular key.

1 Lays eggs Monotreme

Does not lay eggs Go to 2

2 Young born undeveloped, continue to grow in a pouch Marsupial

Young grow in a placenta (womb) and born developed Placental

8 a In the key drawn in Q5, there is no similarity between amphibians and reptiles. Responses will vary depending upon the research students perform.

b Amphibians are different to fish in the type of skin covering.9

Objects

Have corners on objects

No corners on objects

Has 3 corners

Has 4 corners

Has 5 corners

Solid in middle

Hollow in middle

10 The most useful characteristic was shape and number of corners. These are distinct features that cannot be disputed. Colour could also be used if uncertain names like ochre, rust, golden-brown, desert red were avoided.

11 a Dichotomous branching key.

b A Gip always has straight antenna and three pairs of legs. A Brip does not have three pairs of legs, and is never black.

c i Fripii Thrupiii Brip

d Students must draw a black animal, that does not have 3 pairs of legs, has no wings and is black in colour.

12 Some animals have a larval stage in their life cycle, and their body changes as they develop into adults.

Example – eggs → caterpillar → butterfly. Eggs → tadpole → frog.


14 The keys drawn by different students may be different and correct. It depends on the criteria chosen at each branch in the key. So long as the key identifies the correct objects or living things, the key is correct.

ACTIVITY 2.4 CLASSIFICATION USING SEVEN LEVELS1 Species level.

2 Kingdom level.

3 The human and the snow leopard, because they are the only two species in the same class as each other.

4 The honey bee is the most different organism, since it is classified in a different phylum to the others.

5 The two organisms that would be the most different are the human and the lion fish. They have the most different body types – skin covering, reproduction, breathing and so on.

6 The genus and species name is always written in italics, with the genus name beginning in a capital letter.

7 This name is called the binomial or scientific name.

8 a They have nothing in common (except being animals), since a scorpion is classified into Phylum Arthropoda and a fish is Phylum Chordata. However, the lion fish (Order Scorpaeniformes) have venomous spines on the head and gills, and look like scorpions.

b It is called a lion fish because of its appearance, not because of its internal structure.

9

Kingdom Animalia

Phylum Chordata

Class Mammalia

Order Diprotodontia

Family Macropodidae

Genus Macropus

Species rufus

10 A kangaroo is a mammal, so it has hair, and gives birth to live young which feed on milk. It has all the features of the group of animals we call mammals.

Extension to answer: To a biologist the name Macropus rufus means ‘big foot’ ‘red’. Kangaroos are animals with big feet, and this species is distinctively red.


ACTIVITY 2.5 KINGDOMS OF LIFE1 Animalia, Plantae, Fungi, Monera, Protista.

2 Plantae and Protista.

3 Monera and Protista.

4 Members of the plant kingdom are autotrophic.

5 The animal kingdom could be the most successful, because it has the largest number of species.


106 WORKBOOK ANSWERS

6

Plant Animal

Movement Leaves and flowers face the sun. Tendrils move to find a support.

Large animals able to swim, run, walk, fly. Few animals move with their environment.

Reproduction Flowers produce seeds, which germinate into new plants.

Most lay eggs, some have live young.

Nutrition Make own food using energy from the sun and chemicals from the environment.

Eat ready-made food produced by plants.

Growth Use the energy in food to grow a larger body.

Use the energy in food to grow a larger body

Response Slow responses to sunlight and chemicals in the environment.

Fast responses to food and danger.

Exchange Absorbs carbon dioxide and minerals into body, release waste gases to atmosphere.

Takes in food and oxygen, releases wastes to environment.

Waste Oxygen, water vapour. Undigested food, carbon dioxide, heat.

Water Used as a solvent for cell processes.

Used as a solvent for cell processes.

7

Feature Kingdom Fungi Kingdom Plantae

Movement Does not move freely but some movement through growth and reproduction.

Does not move freely but some movement through growth and reproduction.

Reproduction Produce large numbers of spores, drift through air to a new location.

Some reproduce with spores, cones or flowers and seeds.

Nutrition Obtain energy and nutrients from the environment that they live on.

Make own food from sun energy and nutrients from the environment.

Growth Make new cells from splitting of old cells, and from spores that drift to new locations.

Make new cells from spores, cones or seeds, which grow into new plants.

Response Responds slowly to changes in its environment. E.g. Changing nutrients, changing temperature.

Responds slowly to changes, such as light and nutrients. Vines have tendrils which move in the wind, then wrap around a support.

Exchange Take in oxygen, water and nutrients from environment, release carbon dioxide, water vapour and heat.

Take in carbon dioxide, water and light energy from the environment, and release oxygen, water vapour and heat.

Waste Carbon dioxide mainly. Oxygen mainly.

Water Used in every cell for all cell processes.

Used in every cell for all cell processes.

ACTIVITY 2.6 VERTEBRATE CLASSES1 Fish, amphibians, reptiles, birds, mammals.

2 a True

b Falsec Falsed Truee False

3 Vertebrate animals have a backbone. Invertebrate animals do not have a backbone.

4 Chordate means having a nerve column running down the back. In vertebrates the nerve column is protected by bones called vertebrae. All vertebrates are chordates, but there are a few chordates that do not have vertebrae bones.

5 a Fish and amphibians.

b In external fertilisation the eggs are laid and fertilised in the outside environment (not protected inside the female body). The eggs can dry out, or be eaten by other animals, or escape fertilisation. To ensure that some eggs survive and hatch, many eggs have to be laid.

6

Fish Amphibians Reptiles Birds MammalsEctothermic or endothermic?

Ectothermic Ectothermic Ectothermic Endothermic Endothermic

Body covering?

Wet scales Naked skin Dry scales Feathers Hair or fur

Birth from egg or womb?

Usually eggs, but some live births

Eggs develop into tadpoles, then into adults

Eggs with soft shell

Eggs with hard shell

Mostly live births, but few species lay eggs

7

a Mammals = internal skeleton, endothermic, hair/fur, birth from womb (mostly), internal fertilisation

b Birds = internal skeleton, endothermic, feathers, eggs, internal fertilisation

c Reptiles = internal skeleton, ectothermic, scaly skin, eggs, internal fertilisation

d Fish = internal skeleton, ectothermic, wet scaly skin, eggs, external fertilisation

e Amphibian = internal skeleton, ectothermic, moist skin, eggs, external fertilisation

8 Possible key is:

Animals in Q8

Fur on skin

Two legs on ground

when standing

KANGAROO

SHARK

Four legs on ground

when standing

CAT

LABORADOR

Feathers on skin

Looks like a dog

Black and white colour

Friendly dog

PENGUIN

PIT-BULL DOG

No feathers on skin

Looks like a cat

Bright colours

Aggressive dog

No fur

PARROT


107WORKBOOK ANSWERS OXFORD INSIGHT SCIENCE 7 TEACHER KIT

ACTIVITY 2.7 STRANGE ANIMALSStudents’ own responses.

ACTIVITY 2.8 INVERTEBRATES1 a False

b Truec Falsed Falsee True

2 The branched dichotomous key is:

INVERTEBRATES

Body spongy, with many holes

PORIFERAN Soft body, no shell

MOLLUSC ARTHROPODCNIDARIAN

Outside shell or hard cover

Many tentacles or arms

Proper shell or smooth hard

covering

Tentacles around mouth

of sac like body

Soft body, large foot

Limbs in

parts

WORM MOLLUSCMOLLUSC

Long body without tentacles

Spiny skin with rough covering

Arms with suction discs

Worm-like or

leaf-like

Shell, no segments,

large foot

Body not spongy

ECHINODERM

3 The properties shown in the key are:

•Poriferan–hasspongelikebodywithmanyholes.•Cnidarian–hastentaclesaroundthemouthofasaclikebody.•Mollusc–havearmswithsuctiondiscs,orasoftbodywithalargefoot,

or a shell with no segments and a large foot.•Worm–worm-likeorleaf-likebody.•Echinoderm–spinyskinwithroughcovering.

4 An exoskeleton is a shell or case on the outside of the body that supports the animal. An endoskeleton is a set of bones that are on the inside of the body.

5 No. Many invertebrates do not have a skeleton at all.

6 Both groups, worms and cnidarians, have a soft body with no shell.

7 Cnidarians have a sac like body with a mouth surrounded by tentacles, while worms have a long round or flat body without tentacles.

8 Arthropods have an external skeleton.

ACTIVITY 2.9 REVIEW: CLASSIFICATION1 A

2 B

3 B

4 A

5 B

6 A

7 B

8 C

9 B

10 A

11

Vertebrate An organism with a spine and backbone

Endothermic An organism with a constant body temperature

Invertebrate An organism without a spine and backbone

Ectothermic An organism with a changing body temperature

Exoskeleton An organism’s hard outer shell made of chitin

Autotroph An organism which can make its own food rather than eat others

12 a Exchange

b Reproductionc Nutritiond Response

13 Select from:

• skin covering• reproduction• gills/lungs• body temperature.

14 Food and water.

15 Gas, such as carbon dioxide or oxygen, and nitrogenous waste.

16 Note – the objects in this question do not have names. Possible suggestion:

Key to animals page 35

3 body parts

3 pairs of legs

Wings No wings Same colour all over

Head darker than body

2 body parts

4 pairs of legs

Kesbug

Winged Kesbug

Pale Jerbug

Lambug Jerbug

































Acitivity: Reseraching Australian plants and animalsThe examples of adaptations in the text

are ideal models for students to use to

research and present their own examples of

adaptations of Australian plants and animals

to environmental conditions. This task could

be set as an assessment (literacy is a stated

Learning Across the Curriculum item for this

syllabus content).

Spend time getting students to brainstorm the

range of issues in Australian environments

that pose problems for the survival of plants

and animals. In follow-up discussions, make

students aware of infertile soils as well as

droughts, floods, bushfires, and, in only

restricted areas, low temperatures. Include

environments such as estuaries in which there

are extreme variations of salinity. Students

need to be aware that organisms must be

adapted to compete for reproduction, food

and shelter, no matter how difficult the

physical environment may be.

Encourage students to present their work as

a poster or electronically in a form that can

readily be shared and peer evaluated.

Starter activity: Adaption for survival and reproductionStudents could undertake group research using

secondary sources. Choose one feature of living

things, for example, ‘fly’ or ‘glide’, and research all the

different adaptations that help organisms fly or glide.

Alternatively, students could choose one organism and

research its features, and determine how those features

contribute to the living thing’s success in a particular

environment.

Working in groups, give students an identical

mass of plasticine and a 500 mL measuring cylinder

filled with water. Students have to shape the plasticine

into a creature that needs to swim fast to escape a

predator. Student groups compete against each other by

releasing their creature at the surface of the water in the

measuring cylinder—the one that is fastest to the bottom

wins. Students discuss the winning design.

SYLLABUS LINKS


Knowledge and understandingLW1 There are differences within and between groups of organisms; classification helps organise this diversity (ACSSU111).Students:b classify a variety of living things based on




Activity 2.1.6: Designing an animalSC4-7WS Processing and analysing data and informationSC4-8WS Problem solvingSC4-9WS Communicating

Activity 2.1.7: Eucalypt adaptationsSC4-4WS – Questioning and predictingSC4-6WS – Conducting investigationsSC4-7WS – Processing and analysing data and informationSC4-9WS – Communicating


PAGE BANNER COLOUR SAMPLE


OXFORD INSIGHT SCIENCE 7 TEACHER KIT 109































Differentiation

For less able students:• Themainactivitywillbedemanding

for students with low ability or literacy

problems. Scaffolding will need to be

provided. Encourage students to use

labelled diagrams to convey information.

A T-chart to support the communication

of cause and effect relationships may also

be useful. These students may also need

support to find resources at a suitable level.

of wood, the capsule protects the seed from drying out. The release of the seeds could results from the death of the plant. (Banksia is the group (genus) that generally releases seeds in response to fire.)

• The cuticle is a thick waxy layer that helps prevent water from evaporating from the leaf. This is an advantage to eucalypt trees, which usually live in very arid (dry) environments.

• The function of the oil glands is to store and release oil. The oil deters herbivores and could help the leaf remain rigid in dry times. A waxy surface reduces evaporation from the leaf surface.

• The thick persistent bark of some eucalypts could protect the tree from the heat of fire. The vascular bundles of the plant are close to the bark, and these tissues are vital for the function and survival of the plant.

• Structuredgroupwork(asopposedto

student-selected groups) can help if it has

a cooperative structure and the students

do not just rely on more able students to

submit the work.

ANSWERS

ACTIVITY 2.1.7 Eucalypt adaptations• The gumnut is a woody capsule that

can store the seed for a great length of time. (Fleshy fruits, such as oranges, rapidly decompose and no longer serve as protection for the seeds.) Being made

TEACHER OBOOK EXTRAS > Weblink: Effect of bushfires in Australian plants > Weblink: Eucalypts have a special way of

regrowing after fire w > Weblink: Graphic organisers such as T-charts

STUDENT OBOOK EXTRAS > Risk assessment: Activity 2.1.6 Designing an

animal > Editable risk assessment of the activity written


> Risk assessment: Activity 2.1.7 Eucalypt adaptations


RESOURCES



archaea

bacteria

eukarya

ALL LIFE




methanogens

halophiles

thermoacidophiles

protista

fungi

plantae

animalia

KINGDOM







answer.



















SYLLABUS LINKS

Outcomes SC4-14LW relates the structure and function of

living things to their classification, survival and

reproduction

SC4-15LW explains how new biological evidence

changes people’s understanding of the world

Knowledge and understanding LW1 There are differences within and between

groups of organisms; classification helps organise

this diversity (ACSSU111).

Students:

a identify reasons for classifying living things

d identify some examples of groups of

microorganisms

e outline the structural features used to group

living things, including plants, animals, fungi

and bacteria

• classify,usingahierarchicalsystem,arange

of selected plants and animals to species level

(additional)


Activity 2.3.4: Identifying plantsSC4-4WS Questioning and predicting

SC4-6WS Conducting investigations

SC4-7WS Processing and analysing data and

information

SC4-9WS Communicating

Learning across the curriculum • Critical and creative thinking

• Information and communication technology

capability

• Literacy

• Personal and social capability

Starter activity: The changing face of classificationSome of the concepts in this section may need to be

explained before starting. Ask students if they have

heard of DNA, what is it and how is it used. Most

will have heard about the use of DNA in forensics,

for identification of disaster victims, and possibly in

paternity cases. Explain that it is an important substance

because it is passed on or inherited. It is an example of

genetic material.

Teaching strategyThe concept of rearranging and changing the

classification hierarchy may be daunting for

some students. Structure groups so that less

able students are placed with more capable,

supportive students.

Activity: Investigative processScience can be considered as a series of

investigative processes: questioning and

predicting, planning, conducting, processing,

analysing and communicating investigations.

Along the way, problem-solving is needed

to ensure the whole process is valid. The key

idea is that science is based on evidence,

and the ideas are adjusted appropriately as

the evidence changes or new information is

found.

Place the six headings of the investigative

process around the room and ask

students to work in structured groups (see

Differentiation). Each group will write the

changes to science from the text on sticky

notes and place them in the science process

where they belong.



archaea

bacteria

eukarya

ALL LIFE




methanogens

halophiles

thermoacidophiles

protista

fungi

plantae

animalia

KINGDOM







answer.



















DifferentiationFor less able students:• Theymaystrugglewiththeconceptsand

language, so structured group work where

they are teamed with more able students

might help.

Extension activity‘Extreme communities’, the Making

Connections section at the end of the chapter,

is a case study in changes in science and can

be used as an extension task.

ANSWERS

ACTIVITY 2.3.4: Identifying plantsOrganise an excursion to a local park or reserve, or even within the school grounds, to observe and collect plants. Plants are often described based on their growth habit (grasses and herbs, shrubs, trees, mallees) or growth cycles (annuals or perennials).

QUESTIONS 2.3.5 Classifying plants1 Xylem are tubes that carry water and

dissolved nutrients up from the roots of the plant to every cell. Phloem are tubes that

carry dissolved sugars that the plant makes through photosynthesis to the cells where it is needed.

2 Anthophytes are easily identified by the fact they produce flowers as a means of reproduction.

3 Neither mosses nor liverworts are likely to be found in the desert because they cannot efficiently absorb water from the soil—they do not have true roots. They are found in very damp and shady places or close to the water table.

4 Student responses will vary depending on the samples collected.

5 Winged seeds can travel some distance from the parent plant. When the seed germinates, it has more chance of getting the water and light it needs without competing with the larger parent plant. As plants do not move around, the winged seeds give the plant the opportunity to disperse. Plants cannot adapt by changing location if conditions change, but some of the species are more likely to survive if they have a wide distribution.


7 An advantage of having veins is that solutions and water can be easily transported. We could not be the size we are if we did not have arteries and veins to move materials around. As plants moved onto land, they needed ways of absorbing and transporting water and minerals. The veins let them do this, so they can grow in drier places and grow to a much larger size.


9 a A scientist who studies tree rings is called a dendrochronologist.

b As trees grow, they form new layers of bark or vascular cambium. The rings are the remains of vascular tissue, usually phloem, which tend to be on the outer edge of the vascular cambium.

c Trees usually grow a new layer of vascular cambium every year, so the number of rings in a tree is a good estimate of the age of the tree. The width of the rings is also an indication of the climate of that year. The wider the ring, the more favourable the conditions and the more the tree grew that year.

> Weblink: Background on changes in classification


plants > Editable risk assessment of the activity written


RESOURCES










3Fins present Fish



Has scales Reptiles









Communicating




STUDENT DESIGN TASK







Hair all over body



Male

Bugs

Moggie

Buddy

Scott

Peter

Richard

Vanessa

Stephanie

Long ears

Long tail

Short tail

No facial hair

Facial hair

Red hair

Not red hairFemale

Unable to walk

Able to walk

Short ears


REDBACK FAMILY



a

b

c

d

e



SYLLABUS LINKS







Activity 2.2.2: Dr Redback’s familySC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-8WS Problem solving

Activity 2.2.3: Making a tabular dichotomous keySC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and information

Student design task: Dichotomous keysSC4-4WS Questioning and predictingSC4-5WS Planning investigationsSC4-6WS Conducting investigationsSC4-7WS Processing and analysing data and informationSC4-8WS Problem solvingSC4-9WS Communicating


Teaching strategyIt is often easiest to create a dichotomous key as

you classify the group of objects. So each time the

group is separated, a new branch is added to the

dichotomous key.

Differentiation

For less able students:• Thesestudentswillneedmanyopportunities

to use dichotomous keys. Ensure the

keys they use have clear diagrams and

explanations of any terminology. Keys

developed to identify a range of non-living

items should help them practise the skills.

For more able students:• Directstudentstoexploretheonline

resource ‘What is the key to classification?’.

Activity: Assessment taskUsing dichotomous keys is an important skill

that is easily incorporated into an assessment

task. It is an obvious component of written

class tests, and can be used in practical tests

where students rotate around stations set

up in the laboratory and answer a number

of questions. Questions can be set across a

wide range of abilities. Some questions may

present students with a diagram, e.g. showing

the difference between compound and simple

leaves, asking them to identify a compound

leaf from a set of labelled specimens. Some










3Fins present Fish



Has scales Reptiles









Communicating




STUDENT DESIGN TASK







Hair all over body



Male

Bugs

Moggie

Buddy

Scott

Peter

Richard

Vanessa

Stephanie

Long ears

Long tail

Short tail

No facial hair

Facial hair

Red hair

Not red hairFemale

Unable to walk

Able to walk

Short ears


REDBACK FAMILY



a

b

c

d

e



ACTIVITY 2.2.3 Making a tabular dichotomous key1 The animals in the images, clockwise from top left,

fit the following classes: Birds, Mammals, Fish, Amphibians, Reptiles.

2 A possible tabular dichotomous key for Dr Redback’s family is can be seen on page 104 of the appendix.

STUDENT DESIGN TASK Dichotomous keysThis activity could be modelled to the students by first constructing a dichotomous key, as a class, using the eight characteristics of living things. The key will have three possible outcomes: living, dead and non-living. Test the key out on a range of living, non-living and dead things such as the bushfire example.

Before starting this activity, have students come up with their own peer-assessment criteria. They can then use this to assess each other’s dichotomous keys. The ‘best’ key, as per class consensus, should be put up on display with annotations describing its strengths.

questions may involve only one or two steps

in a dichotomous key while others could be

quite complex. Dichotomous keys can be

used in several stages of assessment, not just

assessment of learning.

ANSWERS

ACTIVITY 2.2.2 Dr Redback’s family• Bugs – rabbit; Moggie – cat; Buddy –

dog; Scott – baby son; Peter – elder son; Richard – Dr Redback; Vanessa – his wife; Stephanie – his daughter; Charlie – bird

Students might benefit from using their fingers to trace the path they take on the key.

Students could be challenged to work backwards from the name of the family member to identify the correct person or animal in the illustration.

Students could be asked to write down the characteristics of each person or animal. These characteristics could be assessed to decide whether they were the most appropriate feature to use for grouping, and whether the feature would be appropriate in a larger group of people and animals.

STUDENT OBOOK EXTRAS > What is the Key to Classification? www.mdsg.

umd.edu/programs/education/interactive_lessons/key

Interactive: Using a dichotomous key

> Interactive task where students use drop-down menus and drag-and-drop items to complete a dichotomous key.

TEACHER OBOOK EXTRAS > Risk assessment: Activity 2.2.2 Dr Redback’s

family > Editable risk assessment of the activity written


> Risk assessment: Activity 2.2.3 Making a tabular dichotomous key


> Workbook 2.3: Using keys > Editable version of workbook activity, which can

be digitally assigned to students for homework > Risk assessment: Student Design Task

Dichotomous keys > Editable risk assessment of the activity written


RESOURCES



Remember














2.3CHECKPOINT










[4 marks]


Octopus

Spider

Human

Crab

Elephant

Frog

Lizard

Snail








• the photograph





TOTal MaRKS [ /35]


ORD

BAN

K




ANSWERS

QUESTIONS 2.3.6 The changing face of classification1 evidence; technology; species; genetic; identify;

classify; accurate; scientists

2 a The names of the original three kingdoms were plants, animals and minerals. The five-kingdom system consists of plants, animals, fungi, monerans and protists. The Three-Domain system includes Eukarya (plants, animals, fungi and protists) and two prokaryotic groups: Archaea and Bacteria.

b The change to five kingdoms was necessary because of scientific advances: greater detail could now be observed and further information found. (Students are likely to have different answers based on whether they actually agree with the changes or not.)

3 The understanding of genetics changed the classification system: species that were originally considered to be related because they looked similar are actually quite different based on the genetic material each one contains.

4 A holotype specimen is the original specimen of an organism from which the description for classification was decided. These are housed in museums.

5 Scientists choose a single organism to represent the species instead of trying to find a description that fits every single individual in the species because there is variation within a species. For example, every human or dog looks different even though they are still part of the same species.

6 A paper system for classification can be very large and hard to sort through. Today, the Internet and online databases allow more sophisticated ways to store, organise and communicate this information.

7 Student responses will vary depending on the species they research.

8 Halophile – extremophile organisms that can survive in conditions of extremely high salt concentrations; Thermoacidophile – extremophile organisms that can survive in conditions of extremely high temperatures and acidity; Methanogen – extremophile organisms that produce methane as a by-product of their metabolic reactions.

9 Cyanobacteria are also called blue-green algae because they are similar in structure to chloroplasts. Gram staining is process of disguising different bacteria based on whether or not their cell walls are stained by crystal violet dye. Gram-positive bacteria will stain with crystal violet dye, whereas gram-negative bacteria have impenetrable cell walls that do not stain with crystal violet dye.

10 Dichotomous keys will vary slightly but should involve the following key terms: kingdom, phylum, class, order, family, genus, species, Animalia, Plantae, Fungi, Monera, Protista, mushrooms, moulds, yeasts, bacilli, cocci, spirilla, mono, diplo, strepto, staphylo, vertebrates, invertebrates, Mammalia, Aves, Reptilia, Amphibia, Pisces, monotremes,

marsupials, placental, arthropods, molluscs, poriferans, nematodes, annelids, platyhelminthes, cnidarians, echinoderms, bryophytes, pteridophytes, coniferophytes, anthophytes.

CHECKPOINT 2.3 Classification today1 Vertebrates have an endoskeleton.

Vertebrates are the group of animals with a backbone and a nerve cord that runs through the backbone. At some stage of their development they have pharyngeal slits and a notochord. Invertebrates have an exoskeleton or no skeleton. Invertebrates are the groups of animals that do not possess a backbone.

2 The five main classes of vertebrates are: Mammalia (e.g. human), Reptilia (e.g. crocodile), Amphibia (e.g. golden bell frog), Aves (e.g. kookaburra), Pisces (e.g. Murray cod).

3 Carolus Linnaeus invented the naming system that is still used today to name living things.

4 Six phyla of invertebrates are poriferans (e.g. sea sponges), cnidarians (e.g. jellyfish, corals, anemones), molluscs (e.g. snails, shell-covered aquatic animals, octopus), nematodes/annelids (worms; e.g. leeches, tapeworms, flatworms), echinoderms (e.g.



Remember














2.3CHECKPOINT










[4 marks]


Octopus

Spider

Human

Crab

Elephant

Frog

Lizard

Snail








• the photograph





TOTal MaRKS [ /35]


ORD

BAN

K




sea stars, sea urchins, sea cucumbers) and arthropods (e.g. spiders, insects).

5 An endoskeleton consists of a system of bones or cartilage that is internal. The muscles that attach to the bones to bring about movement are visible externally. An exoskeleton is a system of hard, rigid structures that are external to the connecting muscles, which operate from within the organism. The exoskeleton and its joints are visible externally.

6 A placental mammal looks like a smaller version of the adult when it is born. Marsupials are furless, blind and approximately 1 cm when born and travel

from the birth canal to the pouch where they attach to a nipple, then feed and grow. Monotremes hatch in an undeveloped state from an egg. They develop in a burrow or pouch and suckle milk from a patch on the mother’s underbelly.

7 Scientists need to classify living things to make sense of all the organisms studied, and identify a specific species in a simple and practical manner. Every species can be given a unique name, as opposed to common names that are often neither consistent nor unique.

8

Animal Vertebrate/invertebrate

Class

Octopus Invertebrate Mollusc

Spider Invertebrate Arachnid

Human Vertebrate Mammal

Crab Invertebrate Crustacean

Elephant Vertebrate Mammal

Frog Vertebrate Amphibian

Lizard Vertebrate Reptile

Snail Invertebrate Mollusc



11 It is critical for scientists to keep reviewing, evaluating and modifying the systems they use for classifying and naming living organisms because new information may cause a change in the classification of a species. With the knowledge associated with genetics, we now know some species are in fact distinct and not closely related. Problems that may arise should this modification not be possible include incorrect data, misidentification of species, inability to classify some species, and new species would not be known.

12 Students responses will vary depending on the selected organisms.

13 Students responses will vary, however, students should mention such things as:

• TheknowledgeoflifeontheEarthhaschangeddramatically because of the changes and advances in technology. We can now access more environments and understand more about the structures and function of organisms, the make-up of their genetic material, and other biochemistry.

• Oneexampleisthediscoveryofthedeepunderseacommunities near volcanic vents. A vast new array of organisms has been revealed near these vents, and scientists have learned more information about ways of obtaining nutrition from compounds such as hydrogen sulfide. Technologies for exploration of these depths, as well as sophisticated microscopes, have allowed these discoveries.


STUDENT OBOOK LINKSWeblink: Mythbusters – Daddy longlegs minimyth

> A Mythbusters clip that demonstrates scientific questioning and the gathering of new information that may change classification

Checkpoint Worksheet: Support 2.3

> Digitally assignable worksheet designed to support struggling students to help bring them up to the expected level

Checkpoint Worksheet: Consolidate 2.3

RESOURCES



classification 2 - oxford university...

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