1. Chapter 3.2 – Classifying and Naming Organisms
(pages 85 – 92)
Chapter 3.2 – Classifying and Naming Organisms

2. 3.2 Classifying and Naming Organisms
In this section you will:
Explain how organisms are classified in domains and kingdoms
Explain how organisms are names using a two-name system called binomial nomenclature
Identify species using a dichotomous key

3. The Classification of Organisms
Taxonomy: the practice of classifying living things

4. Classification
Because of the differences in languages and cultures ecologists needed a common method of classifying organisms to improve scientific communication.
Taxonomy- Practice of classifying living things

5. Early Classification
Aristotle (Greek philosopher) began classifying organisms into kingdoms (plants and animals)
Kingdom Plantae
Kingdom Animalia
There was further classification based on size, movement, etc.
BUT there were limitations to such classification
The discovery of micro-organisms forced scientists to reconsider criteria.
Ernst Heckel
Neither animal nor plant- Protista
Taxonomy began approximately 2000 years ago when Aristotle divided the 1000 known organisms into two large groups: plants and animals.
He called each group a kingdom.
Aristotle further classified animals based on their size and the way they moved.
Aristotle classified plants based on their stem characteristics.
Aristotle’s method of classification had limitations and was changed over time.

6. Life is currently divided into 6 distinct kingdoms and 3 domains:
3 Domains of Life
6 Kingdoms of Life
Archaea
Bacteria
Eukaryota
Archaea
Bacteria
Protista
Fungi
Plantae
Animalia

7. Domains The six-kingdom system recently revised
Three major domains, which are large groups that encompass all the kingdoms
Eukarya
Bacteria
Archaea
NOT IN NOTES

9. The Six Kingdoms Archaea Bacteria Protista Fungi Plantae Animalia
Single-celled prokaryotic organisms that live in extreme environments
Bacteria
Single-celled prokaryotic organisms that live in a wide range of habitats
Protista
Consists of both single and multi-celled eukaryotic organisms
Fungi
Single and multi-celled eukaryotes that secrete enzymes to digest their food
Plantae
Eukaryotic multi-celled organisms that use photosynthesis
Animalia
Eukaryotic multi-celled organisms that are heterotrophs
With a partner: Come up with a way to remember these Kingdoms! Can copy the features of kingdom.

10. Multiples chromosomes True membrane bound nucleus
HOLD UP: Do you remember this?
Eukaryotes
Prokaryotes
Animals and Plants
Multiples chromosomes
True membrane bound nucleus
Nucleus- powerhouse/brain
Bacteria and Archaea
One, but not true chromosome (plasmids)
No membrane bound nucleus
HOLD UP: Do you remember this?

11. Archaea single-celled lack membrane bound nucleus
capable of living in extreme environments
Examples: deep sea vent bacteria, thermal springs bacteria

12. Bacteria single-celled lack membrane bound nucleus
Examples: E. coli, salmonella

13. Protista cells contain a nucleus (eukaryotic)
Unicellular and multicellular
autotrophs and heterotrophs
Examples: algae and protozoans

14. Fungi cells contain a nucleus (eukaryotic)
secrete digestive enzymes and absorb the molecules released
Heterotrophs (no chloroplasts)
Examples: mushrooms, molds, yeast

15. Plantae cells contain a nucleus (eukaryotic)
multicellular; specialized tissues
Autotrophs (produce their food)
Examples: mosses, ferns, coniferous trees, flowering plants

16. Animalia cells contain a nucleus (eukaryotic)
multicellular; specialized tissues
Heterotrophs (ingest their food)
Examples: insects, mammals, birds, reptiles

17. The Levels of Classification
There are 8 separate levels of classification
These 8 levels are, from most inclusive to most exclusive:
Domain  Kingdom  Phylum  Class  Order  Family  Genus  Species
This system (minus the Domain classification) was developed by Carolus Linnaeus

18. To distinguish among groups that had similar characteristics Carolus Linnaeus subdivided each category into smaller and smaller groups of more and more similar organisms by using simple physical characteristics to categorize and describe organisms.
At each level of organization, there are more and more similarities among members of the group.

19. Acronyms King Philip Came Out For Great Soup
Kingdom, Phylum, Class, Order, Family, Genus, Species
King Philip Came Out For Great Soup
Karen Played Checkers Over Four Green Slugs
Kids Put Cheese On Fried Golden Slices
Ex.

20. Group domain – Eukarya kingdom – Animalia phylum – Chordata
class – Mammalia
order – Carnivora
family – Felidae
genus – Lynx
species - rufus

21. Naming Systems
Binomial nomenclature, or a two-name or binomial system is used for naming organisms
first word is the genus (capitalized)
second is the species
These names are recorded in Latin and occasionally Greek (consistent regardless of the language)

22. Binomial Nomenclature
Based on last 2 categories Genus species
Purple hydrangea – Hydrangea
macrophylla
Green brittle star - Ophiarachna incrassata
Peacock spider - Maratus volans

23. Lets put the whole thing together: Classifying the Human
Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Homo
Species: sapiens

24. Changing Names
With ability to genetically sequence the DNA now can verify classification
Ex. Skunks recently removed from family that contains weasels.
Now placed in their own family

25. WITHOUT LOOKING AT YOUR NOTES:
What are the 3 Domains of classification and one thing about each?
List the classification categories in order.

26. Dichotomous Keys
Dichotomous Key: Identification key that uses observable characteristics to identify organisms through a series of steps. Two statements are given at each step.
A dichotomous key is a tool that allows the user to determine the identity of items in the natural world based on the items characteristics
"Dichotomous" means
“divided into two parts” Greek origin
dichotomous keys always give two distinct choices in each step, often they are opposites
Black/white; good/evil; pointed/rounded

27. Here are creatures we don’t know!
How to use a Dichotomous Key?
Here are creatures we don’t know!
Lets choose one 27

28. How to use a Dichotomous Key?
Choose only one creature at a time. 28

29. Decide which statement is true
How to use a Dichotomous Key?
Read steps 1a and 1b
Decide which statement is true
1b is true

30. Then follow the directions after that step.
How to use a Dichotomous Key?
Then follow the directions after that step.
Go to step 5!

31. At choice 5, you make another dichotomous choice
How to use a Dichotomous Key?
At choice 5, you make another dichotomous choice
5a is true
Go to step 6!

32. C How to use a Dichotomous Key? Keep going until you come to a step
that gives you the creature’s name.
6 a. The creature has one antennae Go to Step 7. C

33. How to use a Dichotomous Key?
Choose a new creature and start at step 1a and 1b again. Continue until you find the creature’s name. C
Where do you start Again?

34. 1. a. wings covered by an exoskeleton – go to step 2
b. wings freely observed – Go to step 3
2. a. body has a round shape ……….ladybug, a red beetle with black spots
b. body has an elongated shape ……….grasshopper, a green insect that hops
3. a. wings point out from the side of the body ……….dragonfly, an insect that is cm long and lives in marshes
b. wings point to the posterior of the body ……….housefly, a flying insect with red eyes and an annoying buzz

35. What if I Needed to Make a Key:
- Use constant characteristics rather than variable ones. (Flowers change with the seasons)
- Use measurements rather than terms like "large" and "small".
Make the choice a positive one
- something "is" instead of "is not".
- Ex: snake ears are internal only
If possible, start both choices of a pair with the same word or item.
- the body is “round” vs the body is “square”
- Finish the dichotomous key with a full description of the organism

36. Dichotomous key
Another Example of a dichotomous key…

37. Dichotomous key
the dichotomous key can also be expressed in a diagram form