1. The science of naming and classifying organisms is called TAXONOMY
Classification & Taxonomy Part 1
The science of naming and classifying organisms is called
TAXONOMY
Remind students that science is always changing because of new discoveries. This goes for classifying and naming organisms too!

2. How are organisms classified?
1. Scientists begin with similarities in structure and function.
-Type of Cell
-Unicellular or Multicellular
-Mode of Reproduction
-Mode of Nutrition
-Ability to move
2. Then they look at other factors such as evolutionary connections (phylogeny), habitat, and niche.
What is this first organism?
How does this second organism relate to the first?
And the third?
And the fourth?
All of these organisms are known as birds. When we hear the word bird, we immediately form a mental picture in our minds of what birds look like.

3. WHY CLASSIFY?
Reason #1 To name organisms and group them in a logical manner.
Ask students: What characteristics do these organisms have that might lead scientists to group them together?
What differences do they have that distinguish one from the other?

4. What is the name of this animal?
All of the above…these are common names for the same animal.
Puma
Cougar
Mountain lion
Panther

5. WHY CLASSIFY?
Reason #2 To avoid confusion caused by regional names.

6. LEVELS OF CLASSIFICATION
Domain most general Kingdom Phylum Class Order Family Genus Species most specific
Each level is called a taxon
You may want to have students draw an upside down triangle and draw 7 horizontal lines across to divide the pyramid up into 8 sections. Then have the students list the 8 taxonomic categories from top to bottom, starting with Domain at the top in the widest section and ending with species at the bottom in the smallest section.

7. Domains are the broadest level of classification.
Archaea and Bacteria contain all prokaryotes which are thought to be the earliest forms of life on Earth.
Eukarya contains all eukaryotic organisms .

8. Remember! What is a prokaryote? What is a eukaryote?
A single cell organism with no nucleus or membrane bound organelles
DNA is free floating in cytoplasm
What is a eukaryote?
An organism whose DNA is enclosed in a nucleus
Contains organelles

9. Each of the domains is further divided into KINGDOMS by the shared characteristics of the organisms within the domain.
Kingdoms are divided into phylums; phylums are divided into classes, and so on…

10. The more taxonomic levels that two organisms share, the more closely related they are considered to be.

11. Mnemonic devices make it easy to recall the levels!
Domain Did
Kingdom King
Phylum Philip
Class Come
Order Over
Family For
Genus Good
Species Spaghetti?

12. Taxonomic examples Kingdom Phylum Class Order Family Genus Species
Organism
Cat
Wolf
Fly
Kingdom
Animalia
Phylum
Chordata
Arthropoda
Class
Mammalia
Insecta
Order
Carnivora
Diptera
Family
Felidae
Canidae
Muscidae
Genus
Felis
Canis
Musca
Species
F. domesticus
C. lupus
M. domestica
Give students time to analyze this chart before advancing to show the questions. Ask them to notice what taxonomic levels are shared between all three organisms. Then proceed to having them answer the questions.
At what classification level do cats and wolves diverge (become different)?
Which 2 animals are most closely related?
Cat and wolf
Family

13. wolf
dog
fox
Mountain lion
All belong to the same Kingdom: Animalia
Same phylum: Chordata
Same class: Mammalia
Same order: Carnivora
Dog, wolf, fox all belong to the same family: Canidae
Dog and wolf belong to same genus: Canis
Dog and wolf are different species
What are some ways these animals are similar and what are some ways they are different?

14. How do we name organisms?
Carl Linnaeus is known as the Father of Taxonomy (1700’s)
Linnaeus developed the two-word naming system…binomial nomenclature.

15. Binomial Nomenclature
Rules of
Binomial Nomenclature
Each organism is given a scientific name based on its genus and species.
Written in Latin
1st word represents genus and 2nd word represents species
The genus is ALWAYS capitalized and the species is NOT!
Names can also be underlined or italicized

16. Ursus maritimus Polar bear Lower case Capitalized
(genus)
(species)
Underlined instead of italicized!

17. What is your scientific name?
Genus: Homo
Species: sapiens
Correctly written: Homo sapiens
Your dog is Canis familiaris
Your cat is Felis catus

18. Which of the following is the correct scientific name of an organism?
equus caballus
Black stallion
Equus caballus
horse

19. Which organism is most similar to the sandhill crane, Grus canadensis?
Branta canadensis
Falcipennis canadensis
Grus americana
Recurvirostra americana