Chapter 18Classification

18.1 Vocabulary• Taxonomy• Binomial Nomenclature

• Taxon• Species

• Genus• Family• Order• Class• Phylum• Kingdom

Is classification necessary?

• Imagine…•You’re craving milk and cereal for breakfast and you’re at a grocery store. Where would you find milk and cereal? How is the store “classified”? Are all stores similar?

•You want to listen to your favorite song on your iPod. How are your songs “classified”?

Classification = Being Organized!• When you have a lot of information, it is best to

organize and group this information so that it is easier for you to find or see the relationship between these things.

• Imagine if Amazon was not classified!• Now imagine the amazon rainforest!!

How do scientists classify organisms?• “Common names” are used by most people and can be very confusing or misleading

• For this reason, scientists needed a universal naming system with a CONSISTENT naming method.

• Sea lion?• Ant lion?• Lion?

Which one of these is NOT actually a bear?

Consider this…

• Are all “Grey Wolves” gray?

• Are all “Black Bears” black?

• Which is more venomous, a water moccasin or a cotton mouth?

Linnaeus’s System of Classification• Developed by botanist, Carolus

Linnaeus who used Greek and Latin names for organisms

• Binomial Nomenclature: two-word naming system• Each species has a “scientific name” (Genus + Species)

• Organized by important similarities

• Kingdom• Phylum• Class• Order• Family• Genus• Species

• King• Philip• Came• Over• For • Good• Soup

Grouping

HumansKingdom AnimaliaPhylum ChordataClass MammaliaOrder PrimateFamily HominidaeGenus HomoSpecies sapiens

The scientific name is always the genus + species

Humans = Homo sapiensPhoto by atomicshark

Lion Tiger Pintail DuckKingdom Animalia Animalia Animalia

Phylum Chordata Chordata Chordata

Class Mammalia Mammalia Aves

Order Carnivora Carnivora Anseriformes

Family Felidae Felidae Anatidae

Genus Panthera Panthera Anas

Species Leo Tigris acouta

What are the scientific names of each of these organisms?

Naming Rules• Binomial Nomenclature is a 2-name system

• (genus + species)• Scientific names must be underlined or

italicized• The genus is always Capitalized, the

species is lowercase• The genus can be abbreviated

• Example:• Common Name: Grizzly Bear• Scientific Name: Ursus arctos or U. arctos

An organism that can interbreed and produce fertile offspring.

What is a species?

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

Examples: Ligers and Mules are usually infertile

Modern Evolutionary ClassificationChapter 18.2

Phylogeny & Cladograms

A shoe is still a shoe! A monkey is still a monkey! A human is still a human!

Kingdoms & DomainsChapter 18.3

• All organisms can be placed into one of the six kingdoms• Eubacteria• Archaebacteria• Protista• Fungi• Plantae• Animalia

• Classification into a kingdom is based on certain criteria• Type of cell• Number of cells• How it obtains energy

Six Kingdoms

• Cell type: Eukaryotic (cells have nucleus)

• # of cells: Multicellular• Energy: Heterotrophic

(cannot make their own food)

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

KINGDOMANIMALIA

• Cell Type: Eukaryote

• # of Cells: Multicellular

• Energy: Autotroph (make their own food by photosynthesis)

• Examples: mosses, ferns, flowering plants

Photo by hira3

KINGDOM PLANTAE

• Cell Type: Eukaryote• # of Cells: Most multicellular, some unicellular• Energy: Heterotroph (decomposers)• Examples: Mushrooms, yeast

Photos by nutmeg66

KINGDOM FUNGI

• Cell Type: Eukaryote• # of Cells: Most unicellular (some colonial, some

multicellular)• Energy: Autotroph or Heterotroph• Examples: Amoeba, slime molds, giant kelp (most

live in water)

KINGDOM PROTISTA

KINGDOM ARCHAEBACTERIA & KINGDOM EUBACTERIA

ARCHAEBACTERIA• Cell Type: Prokaryote

(no nucleus)• # of Cells: Unicellular• Energy:

Auto/Heterotroph• Examples: Common

bacteria like E. coli or Streptococcus

EUBACTERIA• Cell Type: Prokaryote

(no nucleus)• # of Cells: Unicellular• Energy:

Auto/Heterotroph• Examples:

Extremophiles (live in extreme conditions)

THE THREE DOMAINSRecently, scientists have added a group above Kingdom.  Three

groups, called DOMAINS, contain each of the six kingdoms.

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

Domain Bacteria - includes all prokaryotic cells, Kingdom Eubacteria

Domain Archaea - includes only "ancient" bacteria, Archaebacteria