1. Classification of living things
CHAPTER 18
Classification of living things

2. CLASSIFYING ORGANISMS
Taxonomy- the science to classifying organisms How do we use taxonomy in our everyday life? SUPERMARKET- How would you go about finding the Edam Cheese? What ways would you classify it? Start at the most basic and get more specific?

3. WAYS TO CLASSIFY LIVING THINGS
How they obtain food? AUTOTROPH- produces its own food HETEROTROPH- has to consume food from outside sources

4. WAYS TO CLASSIFY LIVING THINGS
Number of Cells UNICELLULAR- contains only one cell MULTICELLULAR- has many cells

5. WAYS TO CLASSIFY LIVING THINGS
Does it have specific cell parts NUCLEUS PROKARYOTE- is lacking a nucleus EUKARYOTE-has a true nucleus

6. WAYS TO CLASSIFY LIVING THINGS
Does it have specific cell parts? CELL WALL Can be made of CELLULOSE (plants), CHITIN (fungi) or PEPTIDOGLYCAN (eubacteria), S- Layer (archaebacteria)

7. WAYS TO CLASSIFY LIVING THINGS
Make a table that looks like the following
Kingdom
# of cells
Nucleus
Obtains food
Type of cell wall
Do they move
example
Archae bacteria
Eubacteria
Protists
Fungi
plants
Animals

8. ARCHAEBACTERIA
Single cell No nucleus Are AUTOTROPHS and HETEROTROPHS Cell wall of S- layer Live in extreme conditions- some can move example METHANOGENS live in swamps THERMOPHILES- live in hot springs

9. EUBACTERIA
Single cell No nucleus Are AUTOTROPHS and HETEROTROPHS Cell wall made of peptidoglycan Some can move Common bacteria- Staphylococcus aureus- found on our skin Clostridium tetani- causes tetanus E. coli- live in our intestines

10. Protists
Unicellular Contain a true nucleus Can be an autotroph or heterotroph Some can move Examples ALGAE AMOEBAS PARAMECIUM PLASMODIUM-

11. FUNGI Usually multicellular Have a nucleus Cell wall made of chitin
Are HETEROTROPHS- feed on dead organisms
Cannot move
Examples
Mushrooms
Yeasts- used in making bread
Athlete’s foot-

12. PLANTS
Multicellular With a true nucleus- EUKARYOTE All are AUTOTROPHS Cell wall made of CELLULOSE- (starch) None can move EXAMPLES GYMNOSPERMS- plants that produce cones ANGIOSPERMS- plants that produce flowers

13. ANIMALS
Multicellular Have a nucleus (eukaryote) Are HETEROTROPHS Do not have a cell wall Can move about EXAMPLES VERTEBRATES- have a back bone INVERTEBRATES- lacking a back bone

14. Taxonomy? How did we decide to name a species?
Carolus Linnaeus – ( ) devised a system of grouping and naming. He based this on the organisms morphology

15. Before Linnaeus
Some organisms could have names as long as 12-words. Linnaeus simplified the system of taxonomy into two words.

16. How do we determine a species name?
BINOMIAL NOMENCLATURE- a two word system in which the first word is the GENUS name (always capitalized) and the second word is the SPECIES name (always small letters) **** always use italics when naming a species

17. Levels of Classification
Goes from most general to most specific!!!! KINGDOM- 6 PHYLUM CLASS ORDER FAMILY GENUS SPECIES MILLION

18. LION
K- Animalia P-Chordata C-Mammalia O-Carnivora F-Felidae G-Panthera S-Panthera leo

19. Humans K- Animalia P-Chordata C-Mammalia O-Primates F-Hominidae G-Homo
S-Homo sapien

20. YOUR ASSIGNMENT
CREATE A MNEUMONIC FOR THE ACRONYM TO REMEMBER THE PROPER ORDER

21. Is a hippopotamus more closely related to a pig or to a whale
Is a hippopotamus more closely related to a pig or to a whale? List 3 reasons to defend your answer.

22. HIPPO WHALE
Based on physical comparisons (particularly dental structure and number of toes) it was originally thought that hippos were most closely related to pigs but DNA analysis indicates that hippos are more closely related to whales!

23. PHYLOGENY
the study of evolutionary history and relationships of organisms
Use more DNA now than morphology-
Can classify extinct species-

24. Which pair is more closely related
Which pair is more closely related? A lizard/crocodile or bird/crocodile?

25. Cladograms are used to…
Organize organisms based on evolutionary relationships (phylogeny).
In other words… who is related to who and where did we come from…

26. Important Definitions
Node: a branch point in a tree (a presumed ancestral OTU)
Branch: defines the relationship between the taxa in terms of descent and ancestry (trait)
Topology: the branching patterns of the tree
Branch length (scaled trees only): represents the number of changes that have occurred in the branch
Root: the common ancestor of all taxa
Clade: a group of two or more taxa or DNA sequences that includes both their common ancestor and all their descendants

27. Step 1 – Create a Venn Diagram
How many organisms are you comparing?
This number will equal the number of circles in your Venn diagram.
Now count the number of characters each organism has.
This will be the order that you place the organisms in the Venn Diagram.

28. Venn Diagram Placenta: Human Mammary glands: Kangaroo & Human
Two pairs of limbs: Bullfrog, kangaroo & Human
Vertebrae: Shark, bullfrog, kangaroo & humans

29. Step Two – Convert the Venn Diagram into a Cladogram
Kangaroo
Bullfrog
Human
Shark
Placenta
Mammary Glands
Two pairs of limbs
Vertebrae

30. Systematics -cat example
-branch tips = extant spp; root = common ancestor; branches = history of descent; node = point where 1 spp split into 2+ descendents
-lynx & bobcat closest relatives, share a more recent common ancestor with each other than with any other spp on the tree; therefore called ‘sister taxa’
-‘taxon’ any named group of organisms, genus, spp, family etc.
-leopard derived with descent with modification from recent ancestors with similar coats and distant ancestors with flecks
-this is a hypothesis!
-we do not know true history, we identify most plausible scenario
-different data sets can produce different trees
-branch lengths arbitrary, arranged to improve readability
-root establishes order of divergence events

31. A CLADE is a group of organisms that come from a common ancestor.

32. How to read a Cladogram
Species B and C each have characteristics that are unique only to them.
But they also share some part of their history with species A. This shared history is the common ancestor

33. Look at the cladogram at the right
Look at the cladogram at the right. What conclusions can be drawn about the relationship between humans and chimps?