1. Classifying Organisms Mr. Ecklund 7/8 Grade Science

2. Why do Scientists Classify? Imagine a grocery store… How are they organized? What would happen if they were not organized? How is your life organized?

3. Why do Scientists Classify? Almost 2 million kinds of organisms on Earth Need to keep organized! (Easier to study!) Classification = process of grouping things based on their similarities

4. Why do Scientists Classify? Taxonomy =scientific study of how living things are classified Useful because: once classified, scientists will know a lot about an organism

5. Early Classification Systems Aristotle (4 th century B.C.) -observed animals -watched appearance, behavior, movement -fly, swim, and walk/crawl/run -observed similarities and differences -used differences to divide into smaller subgroups

6. Linnaeus Carolus Linnaeus (1750s) -used observations as basis of his system -placed organisms based on observable features Devised naming system for organisms: Binomial Nomenclature

7. Linnaeus =2 part naming system -uses Latin words Genus speciesFelis concolor Genus is capitalized; species is NOT. If you can’t italicize, underline the genus and species!

8. Classification Today Species with similar evolutionary histories are classified more closely together. -when organisms share a common ancestor, they share an evolutionary history

9. Levels of Classification -based on contributions of both Aristotle and Linnaeus There are 7 levels of classification. Remember the first letter of this sentence: King Philip Chases Old Fat Girl Scouts.

10. 7 Levels of Classification Kingdom broadest level Phylum Class Order Family Genus Speciesmost specific

12. Using the Classification System Field guides help identify organisms. -they highlight differences between similar organisms (like trees) Taxonomic Key (AKA Dichotomous Key) -paired statements that describe the physical characteristics of different organisms

13. Taxonomic Key 1. Fruits occur singly....................................................... Go to 3 1. Fruits occur singly....................................................... Go to 3 1' Fruits occur in clusters of two or more......................... Go to 2 1' Fruits occur in clusters of two or more......................... Go to 2 2. Fruits are round....................................................... Grapes 2. Fruits are round....................................................... Grapes 2' Fruits are elongate................................................... Bananas 2' Fruits are elongate................................................... Bananas 3. Thick skin that separates easily from flesh.............Oranges 3. Thick skin that separates easily from flesh.............Oranges 3' Thin skin that adheres to flesh.............................. Go to 4 3' Thin skin that adheres to flesh.............................. Go to 4 4. More than one seed per fruit............................ Apples 4. More than one seed per fruit............................ Apples 4' One seed per fruit............................................ Go to 5 4' One seed per fruit............................................ Go to 5 5. Skin covered with velvety hairs.................... Peaches 5. Skin covered with velvety hairs.................... Peaches 5' Skin smooth, without hairs........................... Plums 5' Skin smooth, without hairs........................... Plums