1. Classification
Chapter 18

2. 18-1 Order in Diversity:
A classification system is used to name organisms and group them in a logical manner
Taxonomy: giving names to organisms that are accepted world wide
Eliminates problems with common names
Ex. the puma, cougar, mountain lion and panther are all names for the same animal
Can be confusing to mix names up when speaking about the same animal to other people

3. Binomial nomenclature:
Developed by Linnaeus
Used for scientific names of organisms
2 part names (Consisting of the genus and species)
always written in italics
1st name is always capitalized, while the 2nd is always lower case
Ex. Homo sapiens

4. Classification System (7 main parts)
King Phillip Came Over For Great Soup
Kingdom (largest)
Phylum
Class
Order
Family
Genus
Species (smallest)
Each higher category contains all the organisms in the groups below it

5. Dichotomous Keys Wacky People Key 1a Two feet 2
1b Some other number of feet 3
2a Does not look at all human 4
2b Looks a lot like a human 5
3a One leg 6
3b Three or four legs 7
4a Fly-like
Mosk Cara
4b Not fly-like 8
5a Seems to be a girl
Rita Nita
5b Not a girl 9
6a Leg is curled , two feet
Ru-ela.Brella
6b Leg is straight, one foot
Giggles

6. 18-2 Modern Evolutionary Classification:
In the past, there were problems with classifying organisms
Anatomical similarities vs. evolutionary/genetic similarities
Organisms are now grouped based on evolutionary descent, not just a physical similarity
Known as Evolutionary classification

7. Modern Evolutionary Classification cont’d
Cladograms are used to show relationships among a group of organisms
Lists derived characters along its branches:
Characteristics that show up in recent parts of the lineage.
Ex. Segmentation of parts, molted exoskeleton etc.

8. Cladograms

9. Modern Evolutionary Classification cont’d
DNA and RNA are now used to link organisms at the molecular level.
Can link organisms based on the existence (or lack of) certain molecules
If similar proteins are present in random organisms, they may be related
The more proteins present in common, the more closely related the organisms are.

10. 18-3 Kingdoms and Domains:
Originally only the Plant and Animal kingdoms
Now there is more involved to the process of distinguishing organisms
Bumped to 5 categories (for a while)
Plant
Animal
Fungi-mushrooms etc.
Protista-mostly single cellular eukaryotes
Monera-single cellular prokaryotes

11. 5 Kingdoms

12. Recent Changes Currently 6 kingdoms exist in 3 domains
Monera (from above) was split into bacteria and archaebacteria
Based on how the organisms have evolved independently

13. Domains- A step above the Kingdom
Domain Bacteria: Unicellular prokaryotic cells with a thick cell wall containing peptidoglycan
Contains the kingdom Eubacteria
Domain Archae: Unicellular prokaryotic cells with a cell wall lacking peptidoglycan, while the cell membrane contains lipids not found in any other organism
Contains the Kingdom Archaebacteria

14. Domains- A step above the Kingdom-cont’d
Domain Eukarya: Contain all cells with a nucleus
Contains 4 kingdoms
Kingdom Plantae: photosynthetic autotrophs with cell walls containing cellulose
Autotrophs-can make their own food
Ex. Photosynthetic/Chemosynthetic organisms
Kingdom Animalia: heterotrophs with no cell walls
Heterotrophs-can not make their own food and need to consume it

15. Domains- A step above the Kingdom-cont’d
Kingdom Fungi: heterotrophs with most feeding on dead/decaying matter such as mushrooms and yeast
Kingdom Protista: eukaryotic organisms not classified as animals, plants or fungi
Some are photosynthetic, while others are heterotrophs
This could possibly be broken down into more Kingdoms in the future