Skills of the BiologistSkills of the BiologistBiologists use the Scientific Method to Biologists use the Scientific Method to

study and solve problems. study and solve problems. – ResearchingResearching– Proposing HypothesisProposing Hypothesis– ExperimentingExperimenting– Observing/Collecting DataObserving/Collecting Data– Inferring/Making conclusionsInferring/Making conclusions– GraphingGraphing– CommunicatingCommunicating

ResearchingResearching

Use as many different sources as Use as many different sources as possible to find out information about possible to find out information about the subjectthe subject

Proposing a HypothesisProposing a Hypothesis

““educated guess”educated guess” what you expect to happen in the what you expect to happen in the

experimentexperiment based on your researchbased on your research written in the IF-THEN formatwritten in the IF-THEN format Ex: Ex: IFIF I drink 1 glass of orange juice I drink 1 glass of orange juice

every day every day THENTHEN I will have less colds I will have less colds

ExperimentingExperimenting

When possible use a When possible use a controlledcontrolled experiment experimentOnly change Only change oneone variable at a time variable at a timeHas 4 parts:Has 4 parts:

11. Control group . Control group – group where everything – group where everything stays the same, normal conditionsstays the same, normal conditions2. 2. Experimental group Experimental group – group where 1 – group where 1 thing is differentthing is different

*everything else must stay the same *everything else must stay the same between these 2 groups*between these 2 groups*

3. 3. Independent variable Independent variable – the thing – the thing that is changedthat is changed

4. 4. Dependent variable Dependent variable – what is – what is measured or observed to determine measured or observed to determine if the experiment is working if the experiment is working

ExampleExample

Divide class into 2 groups. Divide class into 2 groups. – One group will drink a glass of oj every One group will drink a glass of oj every

day at lunch for 2 months. day at lunch for 2 months. – The other group will have their normal The other group will have their normal

beverage. beverage. Students will record how many colds Students will record how many colds

they get during this time period. they get during this time period.

Example 2:Example 2:PigPen sees a commercial for a new PigPen sees a commercial for a new cleaning product called “Snoopy cleaning product called “Snoopy Scrub”. This product promises to Scrub”. This product promises to keep your floors cleaner longer. He keep your floors cleaner longer. He decides to do an experiment to see if decides to do an experiment to see if this is true. He divides the floor into this is true. He divides the floor into 2 sides. On one side he uses his 2 sides. On one side he uses his normal cleaner and on the other side normal cleaner and on the other side he uses the Snoopy Scrub. He will he uses the Snoopy Scrub. He will count how many days until each side count how many days until each side is dirty again. After 7 days the side is dirty again. After 7 days the side with Snoopy Scrub is still clean but with Snoopy Scrub is still clean but the other side is covered with dirt. the other side is covered with dirt.

Identify the following:Identify the following:

HypothesisHypothesis Control groupControl group Experimental groupExperimental group Independent variableIndependent variable Dependent variableDependent variable Conclusion that should be madeConclusion that should be made

Practice ExperimentsPractice Experiments

The Simpson ExperimentsThe Simpson Experiments

WorksheetWorksheet

Designing ExperimentsDesigning Experiments

Blind Study Blind Study – When the participant – When the participant doesn’t know if they are in the control doesn’t know if they are in the control group or the experimental group. group or the experimental group. Helps to ensure that they participate Helps to ensure that they participate in the experiment without bias.in the experiment without bias.

PlaceboPlacebo – A “fake” medication given to – A “fake” medication given to a participant in a blind study. a participant in a blind study.

Double blind study Double blind study – when the – when the participants and the doctors are participants and the doctors are unaware who is in the control group unaware who is in the control group or experimental group. or experimental group.

Setting up Experiments Setting up Experiments 1. Design an experiment to determine 1. Design an experiment to determine

if grass seed grows faster in if grass seed grows faster in ultraviolet light compared to natural ultraviolet light compared to natural lightlight

2. Design an experiment to determine 2. Design an experiment to determine if giving a cow a vitamin every day if giving a cow a vitamin every day makes it produce more milk. makes it produce more milk.

Homework Assignment:Homework Assignment:

Design an experiment to test Design an experiment to test something.something.

Be sure your experiment has:Be sure your experiment has:

HypothesisHypothesis

Control GroupControl Group

Experimental GroupExperimental Group

Independent VariableIndependent Variable

Dependent Variable Dependent Variable

Skills of the BiologistSkills of the Biologist– Observing/Collecting DataObserving/Collecting Data

Using all the senses to collect Using all the senses to collect informationinformation

– Inferring/Making conclusionsInferring/Making conclusions Making a possible explanation Making a possible explanation

based on observationsbased on observations

Observing/Inferring Observing/Inferring ExamplesExamples

The tree is green. The tree is green.

The tree is able to perform The tree is able to perform photosynthesisphotosynthesis

Joe is wearing a sweatshirtJoe is wearing a sweatshirt

Joe is coldJoe is cold

The plant is deadThe plant is dead

Miss Albright forgot to water it. Miss Albright forgot to water it.

GraphingGraphing

A visual way to represent large A visual way to represent large amounts of dataamounts of data

Easy, concise, clear to readerEasy, concise, clear to reader Different types – bar, line, pieDifferent types – bar, line, pie

CommunicatingCommunicating

Share your Share your conclusionsconclusions

Assist with Assist with researchresearch– Your ownYour own– Other scientistsOther scientists

Contribute to Contribute to science!science!

Keystone VocabKeystone Vocab

HYPOTHESISHYPOTHESIS – proposed scientifically – proposed scientifically testable explanation for an observed testable explanation for an observed phenomenonphenomenon

FACTFACT – any observation that has been – any observation that has been repeatedly confirmed and accepted as repeatedly confirmed and accepted as true; any scientific observation that true; any scientific observation that has not been refuted. has not been refuted.

OBSERVATIONOBSERVATION – process of obtaining – process of obtaining information by using the senses, information by using the senses, direct method of gathering direct method of gathering informationinformation

INFERENCEINFERENCE – a logical conclusion or – a logical conclusion or opinion that is formed from known opinion that is formed from known facts, evidence or observation facts, evidence or observation

SCIENTIFIC THEORY SCIENTIFIC THEORY – explanation of a – explanation of a natural phenomenon supported by natural phenomenon supported by many observations and experiments many observations and experiments over time, summarizes a hypothesis over time, summarizes a hypothesis that has been supported with that has been supported with repeated testing, no evidence to repeated testing, no evidence to dispute it. Theories can be disproven dispute it. Theories can be disproven but not proven. but not proven.

PRINCIPLE PRINCIPLE – a concept based on – a concept based on scientific laws where general scientific laws where general agreement is presentagreement is present

SCIENTIFIC LAW SCIENTIFIC LAW – Describes – Describes relationships under certain conditions relationships under certain conditions in nature, does not explain WHY in nature, does not explain WHY something occurs. Usually has a something occurs. Usually has a mathematical formula that predicts mathematical formula that predicts the relationship. the relationship.

MECHANISM MECHANISM - a process by which - a process by which something is done or comes into something is done or comes into being. being.

Question of the DayQuestion of the Day Write today’s date and the title of the Write today’s date and the title of the

question in your question of the day page question in your question of the day page and then answer the question.and then answer the question.

Today’s Question Today’s Question Characteristics of Life Characteristics of Life Brainstorm a list of characteristics/traits that Brainstorm a list of characteristics/traits that

you think are necessary in order for you think are necessary in order for something to be considered living?something to be considered living?

Ex: 8/30 Ex: 8/30 Characteristics of LifeCharacteristics of Life

I think all living things must be made of cells, I think all living things must be made of cells, and breath oxygen. and breath oxygen.

Characteristics of LifeCharacteristics of Life

Def: organism – any living thingDef: organism – any living thing

In Bio the following are the traits that In Bio the following are the traits that determine if an object is living or determine if an object is living or nonliving:nonliving:

1. Cellular organization1. Cellular organizationAll organisms are composed of cellsAll organisms are composed of cells– Can be unicellular – made of 1 cells, ex: Can be unicellular – made of 1 cells, ex:

bacteriabacteria– Multicellular – many cells, ex: plants, Multicellular – many cells, ex: plants,

animalsanimals

– Cells are organized to perform certain Cells are organized to perform certain functionsfunctions

– Cells are grouped to form tissuesCells are grouped to form tissues– tissues are grouped into organstissues are grouped into organs– organs are grouped into organ systems organs are grouped into organ systems – organ systems make a complete organ systems make a complete

organismsorganisms

2. Reproduction2. Reproductionorganisms pass on hereditary info organisms pass on hereditary info (DNA) from parent to offspring(DNA) from parent to offspring

– Asexual – only one parent is involved, Asexual – only one parent is involved, the offspring will all be identical to the the offspring will all be identical to the parent and to each otherparent and to each other

– Sexual – 2 parents involved, offspring of Sexual – 2 parents involved, offspring of combination of traits from both parentscombination of traits from both parents

3. Homeostasis “steady state”3. Homeostasis “steady state”– Maintaining stable internal conditionsMaintaining stable internal conditions– Exs: temperature, oxygen levels, pH Exs: temperature, oxygen levels, pH

levelslevels

4. Responsiveness4. Responsiveness– Organism can respond to stimuliOrganism can respond to stimuli– Can be a physical or chemical Can be a physical or chemical

stimulistimuli– Can be external or internal stimuliCan be external or internal stimuli– Exs: bells, touching something hotExs: bells, touching something hot

5. Metabolism5. Metabolism– sum of all chemical reactions in the sum of all chemical reactions in the

body that take in and transform energy body that take in and transform energy and materials from the environmentand materials from the environment

– Energy comes from:Energy comes from: Autotrophs – make using sunlightAutotrophs – make using sunlight Heterotrophs – consume other organismsHeterotrophs – consume other organisms

6. Growth and Development6. Growth and Development– Growth – get bigger or increase the # of Growth – get bigger or increase the # of

cellscells– Development – the changes in an organism Development – the changes in an organism

as it moves from birth to death.as it moves from birth to death.– Dev’t has 5 stages: Dev’t has 5 stages:

BirthBirth growthgrowth MatureMature DeclineDecline DeathDeath

– These can be effected by: disease, These can be effected by: disease, predators, accidents, natural disasters, loss predators, accidents, natural disasters, loss of habitat of habitat

7. 7. GroupsGroups of organisms also need to of organisms also need to have one characteristic to stay living have one characteristic to stay living for a long time. Over time groups of for a long time. Over time groups of organisms must also evolve/change organisms must also evolve/change or they will become extinct as the or they will become extinct as the world around them changesworld around them changes

Investigation: What is Life?Investigation: What is Life? At each of the lab stations discuss the At each of the lab stations discuss the

object seen, determine what it is and object seen, determine what it is and decide which category it represents.decide which category it represents.

Categories include:Categories include:– LivingLiving– Living but currently dormantLiving but currently dormant– Dead (was once living, but has since Dead (was once living, but has since

died)died)– Product of a living organismProduct of a living organism– NonlivingNonliving