1. Classification
Unit 3

2. Classification Activity
Please sit down if you:
Are taller than 5’9”
Have blonde Hair
Have brown Eyes
Are left-Handed

3. Why Classify?
To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner.
Taxonomy: science of classification
By using a scientific name, scientists can be sure everyone is discussing the same organism.
mountain lion ?
 puma?
 cougar ?
 panther?
 Scientific name = Felis concolor

4. Assigning Scientific Names
Aristotle attempted to classify organisms based on where they lived - land, water or air.
With the invention of the microscope, classifying the diversity of life became difficult.
A major step was taken by Carolus Linnaeus who developed binomial nomenclature (two-name naming system.)
In binomial nomenclature, each species is assigned a two-part scientific name, which is always written in italics. First name is capitalized and second is lowercase.

5. Binomial Nomenclature
Ursus arctos
Genus
Species

6. Dichotomous Key
Tool to help user identify living and non-living things.
Dichotomous comes from two Greek words that together mean, “divided into two parts”.
In each step of the key, only two choices are given; a direction is given or the organisms scientific name.

7. Dichotomous Key

8. Dichotomous Key Activity

9. Class Activity!

10. Make your own Dichotomous Key

11. Warm-Up!

12. Linnaeus’s System of Classification
Linnaeus's hierarchical system of classification includes eight levels:
Domain
Kingdom
 Phylum
 Class
 Order
 Family
 Genus
 Species
Each level is called a taxon (pl. taxa).
Species: organisms that look alike and inter-breed under natural conditions.

13. Trick! Definitely Domain Keep Kingdom Pond Phylum Clean Class Or Order
Froggy Family
Gets Genus
Sick Species

14. Read and Respond

15. Warm-Up! What are the eight levels of classification?
What are the 3 domains?
What are the 6 kingdoms?

16. Kingdoms and Domains
Linnaeus's two kingdoms, Animalia and Plantae did not adequately represent the diversity of life.
Microorganisms became kingdom Protista.
Mushrooms, yeasts and molds were placed in Fungi.
Later, bacteria were named kingdom Monera.
More recently, kingdom Monera was subdivided into two groups: Eubacteria and Archaebacteria.

17. Domains Three domains Eukarya (Protists, Fungi, Plantae, Animalia)
Bacteria (Eubacteria)
Archaea (Archaebacteria)

18. Domain Bacteria

19. Domain Bacteria Extremely Diverse Some photosynthetic
Some pathogenic (causing disease)
Some need oxygen to live, others are killed by oxygen
Streptococcus
Escherichia coli

20. Domain Archaea

21. Domain Archaea Live in extreme environments
Volcanic hot springs
Brine pools
Bottom of the ocean
Many can only survive in the absence of oxygen
Halophiles
Methanogens

22. Domain Eukarya

23. Eukarya-Protista Great variety Three basic groups Animal-like
Plant-like
Fungi-like
Amoeba
Paramecium

24. Eukarya-Fungi Feed on dead or decaying matter
Secrete digestive enzymes, then absorb small molecules
Cell walls made of chitin

25. Eukarya-Plantae Non motile-cannot move from place to place
Cell walls made of cellulose

26. Eukarya-Animalia Heterotrophic – must eat others to survive
No cell walls

27. Time to Practice!
Pg 461: # 3-5
Pg 463: Classify the leaves using dichotomous key
Pg 465: #1-5, 8-10