2. 1.SCIENTISTS CLASSIFY ORGANISMS TO HELP ORGANIZE THEM FOR STUDY PURPOSES. 2. THERE ARE MANY DIFFERENT WAYS TO CLASSIFY ORGANISMS. WE WILL USE THE SYSTEM USED IN THE TEXT. 3. ALL ORGANISMS HAVE BEEN GIVEN A SCIENTIFIC NAME. IT MUST HAVE TWO PARTS: GENUS (CAPITALIZED) AND THE SPECIES (NOT CAPITALIZED).

3. -EXAMPLES: -COMMON NAME = HUMAN SCIENTIFIC NAME = Homo sapiens -COMMON NAME – WOLF SCIENTIFIC NAME = Canis lupus 4. SCIENTIFIC NAMES USE LATIN OR GREEK ROOTS. THEY ARE USED WORLD- WIDE SO ALL SCIENTISTS CAN SPEAK “IN THE SAME SCIENTIFIC LANGUAGE.” 5. THE NAMING SYSTEM = BINOMIAL NOMENCLATURE. IT WAS DEVELOPED BY A SWEDE NAMED CARL LINNAEUS.

4. 6. IN THE PAST, ORGANISMS WERE CLASSIFIED VERY SIMPLY – PLANTS OR ANIMALS. WITH NEWER TECHNOLOGY, CLASSIFICATION SCIENTISTS (CALLED TAXONOMISTS) CAN LOOK AT DNA AND OTHER TRAITS TO CLASSIFY ORGANISMS. 7. ORGANISMS ARE CLASSIFIED BY THEIR SIMILARITIES. THE MORE SIMILAR TWO SPECIES ARE, THE MORE LEVELS OF CLASSIFICATION THEY SHARE.

5. 8. THE 7 LEVELS OF CLASSIFICATION FROM LARGEST TO SMALLEST ARE: KINGDOM PHYLUM CLASS FAMILY GENUS SPECIES 9. ORGANISMS IN THE SAME KINGDOM HAVE ONLY A FEW THINGS IN COMMON, WHEREAS THOSE IN THE SAME GENUS ARE VERY SIMILAR. ORDER

6. -EXAMPLE- A WOLF AND A FLEA ARE IN THE SAME KINGDOM. A WOLF AND A DOG ARE IN THE SAME KINGDOM, PHYLUM, CLASS, ORDER, FAMILY AND GENUS!

8. 10. Scientists look at many factors when classifying organisms. These may include physical similarities, evolutionary background, and DNA similarities. 11. A species is a group of organisms that can interbreed and produce fertile offspring. House cats are one species. Types of house cats (persian, siamese, etc) are sub-species. Mountain lions are related to house cats but they are not in the same species.

10. 12. The three domain classification system: -All organisms can be placed into one of the following 3 domains based on their characteristics. -a few terms you need to know: - heterotroph = must eat food -autotroph = can make its own food -eukaryotic = has a nucleus and membrane-bound organelles. -prokaryotic = no nucleus or membrane- bound organelles.

11. A. Domain Archaea- ancient bacteria, single- celled, prokaryotic, may be hetero or autotrophic. May have a cell wall. Usually live in extreme environments. B. Domain Eubacteria – most common bacteria, single-celled, prokaryotic, may be hetero or autotrophic. Many have a cell wall.

12. c. Protista – The “catch-all” kingdom. Eukaryotic, single or multi-celled, heterotrophic or autotrophic. Any organism that does not fit in the other three eukaryotic kingdoms.

13. D. Fungi – Multicellular, eukaryotic, obtain food by absorption (= heterotrophic). Examples – mushrooms athlete’s foot fungus. Have cell walls of chitin. E. Plantae- Multicelluar, eukaryotic and autotrophic. Have cell walls of cellulose. F. Animalia – Multicellular, eukaryotic and heterotrophic.

14. 13. Cladogram – an evolutionary tree that depicts how organisms may be related to each other through common ancestry.

16. SharkBullfrogKangarooHuman VertebraeXXXX Two pairs of limbs XXX Mammary glands XX Placenta X