1. Classification/Taxonomy
Chapter 18

2. Why Classify? To study the diversity of life, biologists use a
classification system to name organisms &
group them in a logical manner.

3. In other words, naming things.
Taxonomy
Defined:
Discipline of classifying organisms and assigning each organism a universally accepted name.
In other words, naming things.

4. Why common names don’t work
Common names vary among languages and regions.
Example:
United Kingdom – Buzzard refers to a hawk
United States – Buzzard refers to a vulture
Red-tailed Hawk
Honey Buzzard
Turkey Vulture

5. Aristotle 384 BC
Classified organisms as either plants or animals

6. Carolus Linnaeus
(1707 – 1778)
Created the system of naming we use today.
In taxonomy, a group or level of organization is called a taxonomic category or taxon.

7. Binomial Nomenclature
“Bi” means 2
“nomial” means number
“Nomen” means name
“Clature” means the system of
Defined:
In binomial nomenclature, each species is assigned a two-part scientific name.

8. Binomial Nomenclature
 Carolus Linnaeus
In binomial nomenclature, each species is assigned a two-part scientific name.
The scientific name is always written in italics or underlined.
The first word (the genus) is capitalized
The second word (the species) is lowercased.
EX- Genus species or Genus species
Humans- Homo sapien

9. Example of Binomial Nomenclature
Polar Bear is Ursus maritimus
Ursus: genus
Ursus contains 5 other kinds of bears
maritimus: species
The Latin word, maritimus, refers to the sea.
Polar bears often live on pack ice that floats in the sea.

10. Linnaeus's System of Classification
A group or level of organization is called a taxonomic category, or taxon
Linnaeus had 7-
Kingdom “King
Phylum Phillip
Class Came
Order Over
Family For
Genus Great
Species Spaghetti”

11. Definitions to know Genus: is a group of closely related species
Species: Group of similar organisms that can breed and produce fertile offspring

12. Family: Group of genera that share many
characteristics
Order: Group of similar families
Class: Group of similar orders
Phylum: Group of closely related classes
Kingdom: Largest taxonomic group,
consisting of closely related
phyla.

13. What do these mean?...lets see
Here We Go… Polar Bear
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Ursidae
Genus: Ursus
Species: maritimus
What do these mean?...lets see

14. What they mean Kingdom: Animalia (there are 6 kingdoms)
*Do NOT have to write*
Kingdom: Animalia (there are 6 kingdoms)
Phylum: Chordata (vertebrates)
Class: Mammalia (warm-blooded, hair, & milk)
Order: Carnivora (meat-eating animals)
Family: Ursidae (larger category of bears)
Genus: Ursus (kind of bear)
Species: maritimus (lives in marine environment)

15. How to remember: King Phillip Came Over For Green Salad
Kingdom Phylum Class Order Family Genus Species

16. Uniqueness: Every name has to be unique.
Rules of the Game
Uniqueness: Every name has to be unique.
Universality: Zoologists have adopted, by international agreement, a single language to be used on a worldwide basis. All animals are given a generic (common name) and specific name in Latin (scientific name).
These names are in italics or are underlined
(i.e. Homo sapiens).

17. Visuals

19. Modern Three-Domain System
As scientists further analyzed cell structure and DNA , a broader category was added-
The domain is the most inclusive taxonomic category; larger than a kingdom   
The three domains are:
Bacteria : kingdom Eubacteria
Archaea,: kingdom Archaebacteria;
Eukarya :Kingdom protists, fungi, plants, and animals.

20. Cladogram of Six Kingdoms and Three Domains
Section 18-3
DOMAIN ARCHAEA
DOMAIN EUKARYA
Kingdoms
Eubacteria
Archaebacteria
Protista
Plantae
Fungi
Animalia
DOMAIN BACTERIA
Go to Section:

21. Modern 6 Kingdom System
Recently, as evidence about microorganisms continue to accumulate, biologists came to realize that the Kingdom Monera were composed of 2 distinct groups.
The 6-Kingdom system of classification includes kingdoms:
1. Eubacteria Archaebacteria Protista
4. Fungi Plantae Animalia

22. 6 Kingdoms Eubacteria Archaebacteria Protista Fungi Plantae Animalia
Prokaryote
Prokaryote
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Autotroph or
heterotroph
Autotroph or
heterotroph
Autotroph/
heterotroph
Heterotroph
Autotroph
Heterotroph
Includes Algae
Don’t belong in other euk
No cell wall
No chloroplasts
Multicellular
“Ancient Bacteria”
Release enzymes to digest food
Most common bacteria
Cell walls
& Chloroplasts
Live in very hot places
E. ecoli
Pyrococcus furiosus
Paramecium
H. coccinea
Fern frod
Homo sapiens

23. Checkpoint Questions:
1.  How are living things organized for study?
2. Describe the system for naming species that Linnaeus developed.
3. What are the seven taxonomic categories of Linnaeus’s classification system?
4. Why do scientists avoid using common names when discussing organisms?
5.  What is significant about members of the same species?