topic 5.3 - classification...2018/07/05 · taxonomy is the branch of biology concerned with...
TRANSCRIPT
TOPIC 5.3 - CLASSIFICATION
5.3 – A – Taxonomy & Naming
Understandings
U3: Taxonomists classify species using a hierarchy of taxa.
Key Terms
Taxonomy
Taxa
IB BIO – 5.3 3
https://upload.wikimedia.org/wikipedia/commons/thumb/7/71/Taxonomic_Rank_Graph.svg/2000px-Taxonomic_Rank_Graph.svg.png
Taxonomy is the branch of Biology concerned with classifying
organsims. Taxonomists do this using a hierarchy of taxa (groups).
From broadest to most specifc, the taxa used are:
• Domain
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species
Understandings
U3: Taxonomists classify species using a hierarchy of taxa.
Key Terms
Taxonomy
Taxa
IB BIO – 5.3 4
http://biology-forums.com/gallery/33_15_07_11_12_02_25.jpeg
Moving upwards, each level of hiearchy includes all of the taxa below
it. So, domains are the most general and have the highest
population while species are the most specific (population of 1).
Understandings
U4: All organisms are classified into three domains.
Key Terms
Bacteria
Archaea
Eukarya
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http://biology-forums.com/gallery/9828_12_01_13_1_40_32.jpeg
All organisms can be classified into three domains of life. Organisms
in each domain have common characteristics. The three are:
Bacteria Archaea Eukarya
Understandings
U4: All organisms are classified into three domains.
Key Terms
Bacteria
Archaea
Eukarya
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http://biology-forums.com/gallery/9828_12_01_13_1_40_32.jpeg
Domain Characteristics
BACTERIA EUKARYOTA ARCHAEA
Histones Absent PresentProteins similar to
histones
Introns Rare ManyPresent in some
genes
Cell Wall Structure
Made of peptidoglycan
Not present in all
Not made of peptidoglycan
Not made of peptidoglycan
Size / Organization
Small / Unicellular
Large / Uni- or Multicellular
Small / Unicellular
Reproduction Asexual Sexual / Asexual Asexual
The following chart shows similarities and differences between the
three domains:
Understandings
U4: All organisms are classified into three domains.
Key Terms
Bacteria
Archaea
Eukarya
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https://upload.wikimedia.org/wikipedia/commons/f/f5/Grand_prismatic_spring.jpg
Compared to bacteria & eukarya, archaeans are found in a broad
range of habitats. This includes extreme habitats with high salt
concentrations and temperatures close to boiling.
Understandings
U4: All organisms are classified into three domains.
G5: Viruses are not classified as living organisms.
Key Terms
Viruses
IB BIO – 5.3 8
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Viruses cannot perform all the
functions of life on their own.
Instead, they depend on the
metabolic processes of host
cells to reproduce.
So, they are not classified as
living organisms and do not fall
into any domain.
Understandings
U5: The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family, genus and species.
Applications
A1: Classification of one plant and one animal species from domain to species level.
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https://upload.wikimedia.org/wikipedia/commons/8/82/Taxidea_taxus_(Point_Reyes,_2007).jpg
Most eukaryotes can be split into: animals, plants, protists or fungi.
Below are classification examples of two types of Eukarya.
Eukarya Domain
Examples
Understandings
U1: The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses.
Key Terms
Binomial Nomenclature
IB BIO – 5.3 10Binomial nomenclature is the
naming system used by scientists
to identify species.
It names them by combining their
genus and species classifications.
The binomial naming rules are:
• The full name is italicized
• Genus is capitalized
• Species is lower-case
• After the first use, the genus
can be shortened to the first
letter.
Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Canidae
Genus Canis
Species Lupus
Dog Classification
Species Name
Genus + Species
Canis lupus → C. lupus
Understandings
U1: The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses.
Key Terms
Binomial Nomenclature
IB BIO – 5.3 11Binomial Nomenclature Practice
http://study.com/cimages/multimages/16/Human_vs_Ostrich_Taxonomy.png
What would the binomial name be for the organisms below?
Understandings
U2: When species are discovered they are given scientific names using the binomial system.
Key Terms
Binomial Nomenclature
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http://2.bp.blogspot.com/-NiMHvoRsia0/UtmdtglzA3I/AAAAAAAAAFo/CjmKrs-nYFk/s1600/linnaeustaxonomy.jpg
When scientists discover new species,
they assign them a scientific name
using the binomial system.
This allows them to communicate
efficiently to deduce potential
relationships with known species.
VID
EO
SIB BIO – 5.3 13• Mahalo: Taxonomic Hierarchy
https://www.youtube.com/watch?v=kKwOlAqQoLk
• Eco Sapien: An Introduction to Taxonomy
https://www.youtube.com/watch?v=NRVJyUZoQow
• Educational Tree of Life: The Three Domains
https://www.youtube.com/watch?v=s9Yf_G7LU3c
5.3 – B – Natural Classification
Understandings
U6: In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species.
Key Terms
Natural Classification
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http://figures.boundless-cdn.com/19053/full/figure-20-01-05.png
In natural classification, scientists
aim to classify species in a way that
reflects evolutionary paths.
So, all members of a
genus or higher should
have a common ancestor.
Understandings
U6: In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species.
Key Terms
Natural Classification
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Because of common ancestry, we
can expect species that fall in the
same higher taxa to share
characteristics.
Moving from broader to more
specific taxa, members will share
more and more traits.
Understandings
U7: Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species.
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https://s-media-cache-ak0.pinimg.com/originals/e9/f7/04/e9f704893a3772a67062caf5c39bbb38.jpg
Natural classification can sometimes be difficult as some species
appear to have similar traits, but are not actually related. For
example, many unrelated species have evolved wings for flying.
Improvements in molecular technology have been used to address
this. New evidence can be used to reclassify species more
appropriately.
Understandings
U8: Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group.
Key Terms
Natural Classification
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Natural classification is helpful
in the research of biodiversity,
particularly when new species
are discovered.
• Identification of species
When unknown species are
encountered, their traits can
be compared to those of
known species.
This allows scientists to
predict its classification in
many taxa.
Understandings
U8: Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group.
Key Terms
Natural Classification
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• Prediction of characteristics
Because members of a group
have common ancestry, they
inherit similar traits.
So, chemicals or processes in
an organism are likely to be
found in organisms of the
same taxa.
The internal structures of
organisms can also be
predicted without direcly
oberving them.
REVIE
WIB BIO – 5.3 201. Define taxonomy.
2. List the levels of hierarchy of taxa from broadest to
most specific.
3. Outline the application of binomial nomenclature in
constructing a species’ scientific name.
4. Define natural classification.
5. Outline two benefits of natural classification when
encountering unknown species.
5.3 – C – Recognition Features
Applications
A2: External recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta.
Key Terms
Recognition Features
IB BIO – 5.3 22Plants Recognition
Plants are classified together in a single kingdom, but can be divided
into four different phyla. Recognition features that can be used to
differentiate between them are shown here:
Applications
A2: External recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta.
Key Terms
Recognition Features
IB BIO – 5.3 23Plants Recognition
Applications
A3: Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata.
Key Terms
Recognition Features
IB BIO – 5.3 24Animal Recognition
Animals are divided into over 30 phyla, based on their
characteristics. Recognition features for 6 phyla are shown here:
Applications
A3: Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata.
Key Terms
Recognition Features
IB BIO – 5.3 25Animal Recognition
Applications
A4: Recognition of features of birds, mammals, amphibians, reptiles and fish.
Key Terms
Recognition Features
IB BIO – 5.3 26Vertebrate Recognition
Most species of chordate belong to one of five major classes, each of
which contains more than a thousand species.
Skills
S1: Construction of dichotomous keys for use in identifying specimens.
Key Terms
Dichotomous Keys
IB BIO – 5.3 27Dichotomous keys are tools that can be used to determine the
identity of an unknown species sample. Each key is made up of
dichotomous (yes/no) questions.
For example, for a given set of organisms:
1. Does it have feathers? Yes go to Q2No go to Q3
2. Does it swim? Yes DuckNo Hen
3. Does it have legs? Yes LizardNo Snake
Skills
S1: Construction of dichotomous keys for use in identifying specimens.
Key Terms
Dichotomous Keys
IB BIO – 5.3 28Dichtomous Key Practice
1. Is it symmetrical? Yes go to Q2No Phylum Porifera
2. Symmetry is… Radial Phylum CnidariaBilateral go to Q3
3. Gastric tube… Mouth & Anus go to Q4Mouth, no anus Phylum Platyhelminthes
4. Segmentation… Yes go to Q5No, or not visible Phylum Mollusca
5. Exoskeleton? Yes Phylum ArthropodaNo Phylum Annelida
Skills
S1: Construction of dichotomous keys for use in identifying specimens.
Key Terms
Dichotomous Keys
IB BIO – 5.3 29Dichotomous keys can also be represented in tree form. Answering
the questions down the treel reveals a specimen’s identity.
http://ib.bioninja.com.au/_Media/dichotomous3_med.jpeg
REVIE
WIB BIO – 5.3 301. Outline the external recognition features of:
- Bryophyta - Filicinophyta
- Coniferophyta - Angiospermophyta
2. Compare the following pairs:
- Porifera & Chordata - Cnidaria & Mollusca
- Annelida & Arthropoda
3. Outline the characteristics of the five major classes
of chordates.
REVIE
WIB BIO – 5.3 314. Construct a dichotomous key that would identify
the following organisms: