TAXONOMY

The Science of Classifying Organisms

What are these animals?�Would you group them together in a zoo?

Classification is about organizing life forms into groups.

How are zoos organized?

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How are your drawers organized?

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How are grocery stores organized?

Why do we need a standard way of naming organisms?

“Common names” can be confusing

The scientific name of a Timber rattlesnake:

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Crotalus horridus

Common Name?

Sea Lion?

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Antlion?

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Lion?

Which one of these is NOT actually a bear?

What kind of organism is it?�(invertebrate, mammal, insect, fish, reptile..)

1. Sea Monkey
2. Firefly
3. Ringworm
4. Jellyfish
5. Spider monkey
6. Crayfish
7. Sea Horse

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Consider this………..

-Are all “Grey Wolves” gray?

-Are all “Black Bears” black?

- Which is more venomous, a water moccasin or a cottonmouth?

Answers: Gray wolves can range from light gray to black; black bears can be brown; water moccasins and cottonmouth are common names for the SAME snake.

Classification System

• developed by Linnaeus who used Greek and Latin names

• all organisms placed into a few *large* groups - KINGDOMS -

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Three Domain System    

Three groups, called DOMAINS, contain the six kingdoms.

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Domain Eukarya - includes organisms composed of eukaryotic cells (plants, animals, fungi, protists)

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Domain Eubacteria - includes all prokaryotic cells, Kingdom Eubacteria

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Domain Archaea - includes only "ancient" bacteria, Archaebacteria

These are the SIX Kingdoms.

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All life on earth can be placed into one of these groups.

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- does not include viruses

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

To help you remember the list

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DOES KING PHILIP COME OVER FOR GREAT SOUP?

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Kingdom, Phylum, Class, Order, Family, Genus, Species

The scientific name is always the genus + species

Humans = Homo sapiens

What are the scientific names of each of these organisms?

The Classification of a Timber Rattlesnake

Which of these names represents a diamondback rattlesnake?

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1. Ophiophagus hannah
2. Lampropeltis getula
3. Crotalus atrox

More on Naming..

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The system of naming is called BINOMIAL NOMENCLATURE - which means it is a 2-name system.

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Rules:

1. names must either be underlined or italicized

2. Genus capitalized, species is lowercase

3. Can be abbreviated. Ex. P. leo and P. tigris

What is a species?

Defined as organisms that can interbreed with one another, and produce fertile offspring

When two organisms of different species interbreed, the offspring is called a HYBRID

Example:  ligers and mules

Kingdoms based on:� -Number of cells (unicellular or multicellular)

-How it obtains energy� (heterotroph or autotroph)

-Type of cell (eukaryote or prokaryote)

Kingdom Animalia

Types of Cells:� Multicellular, Eukaryote

Energy: Heterotrophic

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Examples: birds, insects, worms, mammals, reptiles, humans, anemones

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***Most can move

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Kingdom Plantae

Multicellular, Eukaryotic

Autotrophic

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Cannot move �(due to cell walls)

Kingdom Fungi

Multicellular (most), Eukaryotic

Heterotrophic (mainly decomposers)

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Kingdom Protista

Most are unicellular

Can be heterotrophic or autotrophic

Eukaryotes (all have nucleus)

Examples: Ameba, paramecium, algae

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Giardia - parasite that causes “beaver fever”

Kingdom Eubacteria

- prokaryotes �- unicellular �- common bacteria�- E. coli, Streptococcus

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Kingdom Archaebacteria

- prokaryotes �- unicellular

- “ancient bacteria”

- exist in extreme environments

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LUCA

Quick Check

1. What kingdom contains multicellular autotrophic organisms?
2. What kingdom contains prokaryotes that live on surfaces?
3. What kingdom contains multicellular, heterotrophic organisms that have cell walls?
4. What kingdom contains prokaryotes that live in extreme environments?
5. All organisms that belong to the Phylum Annelida will also belong to the same [ kingdom / class / order ]
6. An organism’s scientific name is the ______ and ______.

Modern Taxonomy:

Clades

A clade is just a fancy name for a group

Phylogeny = the study of evolutionary relationships

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How would you classify a hyena? Would you group it with cats or dogs?

Modern Evolutionary Classification

CLADE = a group that includes a single common ancestor and all of its descendents

CLADOGRAM = a diagram that shows clades and how they are linked

DERIVED CHARACTER = a trait that arose in a common ancestor that all its descendants share

Place an X for each animal that has the trait

4 legs

fur

carnivore

claws

Check out this large graphic showing animal taxonomy.

How to Identify Organisms

A dichotomous key shows a set of choices to help ID an organism.