1. Chapter 18 Classification
The diversity of life

2. Why is it necessary to classify?
1.5 million species on the planet so all creatures must be organized with a universal system. We call this taxonomy.
Scientists cannot use common names because they change depending on where you live.
For example: cougar, panther, puma, mountain lion all represent the same animal. It has a scientific name – Felis concolor

3. Scientific Names
Carolus Linneaus – Swedish botanist who began the modern naming system.
Developed a two word naming system called binomial nomenclature (latin)
2 name naming system
Scientific names are
Descriptive
In Latin
2 words – capitalize the first letter of the first word and lowercase everything else.
First word is Genus second word is species
Ursus maritimus

4. Examples scientific name = genus + species
Homo sapien
Canis familiarius
Felis domesticus
Drosophilia melanogaster
Human
Dog
Cat
Fruit fly

5. Classification System
We organize all life on Earth into 9 levels. Each level is called a taxon.
Domain is the largest – 3 large groups (see below)
Species is the smallest

6. Classification Levels Example: Grizzly bear

7. Here’s how to memorize it
Kings = Kingdom
Play = Phylum
Chess = Class
On = Order
Fine = Family
Grain = Genus
Sand = Species

8. Human Taxonomy Levels

9. Changing Number of Kingdoms
History of Kingdoms:
1700’s - 2 kingdoms –Plants and Animals
1800’s – 3 kingdoms – Plants, Animals, Protists (pond water critters)
1950’s – 5 kingdoms – Monera (bacteria), Protists, Fungi, Plants and Animals
1990’s – Eubacteria, Archaebacteria, Protists, Fungi, Plants and Animals.

10. Section 18-3 Kingdoms and Domains
Shown below are the three domains and the 6 modern kingdoms we use today.

11. Autotroph v. Heterotroph
Autotroph = Create their own food through photosynthesis
Heterotroph = Receive their food through outside resources. They can absorb them or consume them.

12. Domain: Bacteria and Archaea
1. Kingdom: Bacteria
unicellular
prokaryotic
cell wall contains a special molecule called peptidoglycan.
2. Kingdom: Archaebacteria
Live in extreme environments
Cell wall lacks peptidoglycan

13. Domain Eukarya 3. Kingdom Protista
Eukaryotic organisms (most are
one celled)
Shows the greatest variety of organisms
Photosynthetic or heterotrophic
Amoebas, Paramecium, slime molds

14. Domain Eukarya 4. Kingdom Fungi
Absorptive heterotrophs – absorb nutrients through their bodies
Feed on dead or decaying organic matter
Many are multicellular
Yeast is unicellular

15. Domain Eukarya 5. Kingdom Plantae
Multicellular
Autotrophs (do photosynthesis)
Cellulose in cell wall

16. Domain Eukarya 6. Kingdom Animalia
Multicellular
Heterotrophic
Eukaryotic
Invertebrates and Vertebrates

17. Cladogram & Dichotomous Keys
Cladagram: Diagram that shows evolutionary relationships among organisms based on shared derived characters.
Dichotomous Key: A “field guide” to help identify unknown organisms/objects
Based on physical traits
Rules:
Only 2 options at a time
All items still in consideration must fit in one of the two options
No “grey-areas”

18. Let’s practice dichotomous keys
The next slide, I will show you our organisms/objects
For our example, we will use 8 nuts & bolts – keep in mind what they look like.
Normally, we would give each organism/object a scientific name (Genus species). When you practice in class, you will make these up, but make them latin sounding, so add “us” or “is” at the end of the word.

19. Instead of Latin names, I have given them #’s to make this a bit easier to do on PowerPoint!!! Again, when you do this in class, you will make-up a Latin sounding scientific name (Genus species)

20. Construct a Branching Chart first to ultimately make a dichotomous key
Species #1
6 sided
Species #4
Rounded head
Has a hole
Species #6
4 sided
Sharp, pointed tip
Species #7
Not rounded head
8 nuts & bolts
With threading
Species #2
Not a flat head
Without a hole
Species #5
No sharp, pointed tip
Body length twice the width of head
Species #8
Flat head
Without threading
Species #3
Body length NOT twice the width of head

21. First step is to number and letter our branching chart.
Now we are ready to construct a dichotomous key from our branching chart.
First step is to number and letter our branching chart.
Every center horizontal line gets a number
Every choice gets a letter “a” or “b”

22. a a a b a b a a b b a b b b Species #1 6 sided Species #4 2 Species #6
Rounded head
Has a hole b
Species #6
4 sided 5 a
Sharp, pointed tip b
Species #7 1
Not rounded head
8 nuts & bolts 4 a
With threading a
Species #2 b
Not a flat head 3 b
Without a hole
Species #5 6 a
No sharp, pointed tip
Body length twice the width of head b b 7
Species #8
Flat head
Without threading b
Species #3
Body length NOT twice the width of head

23. Finally you write the dichotomous key by coping everything straight from the branching chart.
1a. With a hole
Go to question 2
1b. Without a hole
Go to question 3
2a. 6 sided
Species #1
2b. 4 sided
Species #6
3a. With threading
Go to question 4
3b. Without threading
Species #8
4a. Sharp, pointed tip
Go to question 5
4b. No sharp, pointed tip
Go to question 6
5a. Rounded head
Species #4
5b. No rounded head
Species #7
6a. Not a flat head
Species #2
6b. Flat head
Go to question 7
7a. Body length twice the width of head
Species #5
7b. Body length NOT twice the width of head
Species #3

24. We could also construct a Cladogram based on our nuts & bolts…