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ClassificationClassification

Chapter 18Chapter 18

ClassificationClassification

Chapter 18Chapter 18

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Order From ChaosWhen you need a new pair of shoes, what do you do? You probably walk confidently into a shoe store, past the tens or hundreds of pairs of shoes you don’t want and straight to the kind you do want. How do you find them? Shoes are organized in the store in categories. People organize objects by grouping similar objects together.

Section 18-1

Interest Grabber

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1. Consider the task facing early biologists who attempted to organize living things. How might they have begun?

2. Suppose that you have been given a green plant, stringy brown seaweed, a rabbit, a mushroom, a worm, and a grasshopper. You’ve been asked to organize these things into categories that make sense. How would you do it?

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I. Finding Order in Diversity A. Why classify organisms?B. Classifying

1. grouping organisms logically - based on characteristics

C. Taxonomy1. field of science where organisms are assigned names

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D. Scientific Name 1. a name given to a species (in Latin) that is agreed on universally

E. Binomial nomenclature1. each species is assigned a 2 part scientific name (using the genus, and species)

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Video 1• Click the image to play the

video segment.

Video 1

Panthera leo?, Part 1

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F. Linnaeus’ System of Classification

Seven Levels of Classification1.  Kingdom2.  Phylum3.  Class4.  Order5.  Family6.  Genus

7. Species

(8) Variety

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Grizzly bear Black bear Giant panda

Red fox Abert squirrel

Coral snake

Sea star

KINGDOM Animalia

PHYLUM Chordata

CLASS Mammalia

ORDER Carnivora

FAMILY Ursidae

GENUS Ursus

SPECIES Ursus arctos

Section 18-1Figure 18-5 Classification of Ursus arctos

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Video 2

• Click the image to play the video segment.

Video 2

Panthera leo?, Part 2

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II. Modern Evolutionary Classification

A. Biologists and taxonomists group organisms based on evolutionary descent

1.Phylogeny a. evolutionary relationships among organisms

 Example: Grizzly bear and a black bear are more related to each other than they are related to a Panda bear

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B. Cladograms 1. diagram that shows evolutionary relationships among a group of organisms

  2. shows shared derived characteristics

a. traits that are shared with 1 group and a single ancestor

b. Example: Fur in mammals

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Crustaceans Gastropod

Crab Barnacle Limpet

Molted exoskeleton

Segmentation

Tiny free-swimming larva

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C. Similarities in DNA and RNA1. used to help determine classification and evolutionary relationships2. the more two species have diverged from one another, the less similar their DNA will be

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III. Kingdoms and Domains

 A.Three Domains 1. Bacteria – unicellular,

prokaryotic 2. Archaea – unicellular,

prokaryotic, live in extreme environments

3. Eukarya – organisms with cell nuclei

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B. Three Domains and Their Kingdoms

1. Bacteria a. Kingdom Eubacteria2. Archaeaa. Kingdom Archeabacteria

3. Eukaryaa. Protistab. Fungic. Plantaed. Animalia

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Section 18-3

Concept Map

are characterized by

such as

and differing which place them in

which coincides withwhich coincides with

which place them in which is subdivided into

Living Things

Kingdom Eubacteria

Kingdom Archaebacteria

Eukaryotic cellsProkaryotic cells

Important characteristics

Cell wall structures

Domain Eukarya

Domain Bacteria

Domain Archaea

Kingdom Plantae

Kingdom Protista

Kingdom Fungi

Kingdom Animalia