CH.17 Classification & Taxonomy

TAXONOMY TAXONOMY: A field of biology that identifies and classifies organisms. –Classification Tools: Shared characteristics Evolutionary relationships

Development of a Classification System Carolus Linnaeus was a Swedish biologist. He developed the classification system that is the basis for the system used today. –Established a system of groups called TAXA (singular: taxon) –Arranged from broadest to most specific groups –Contained 5 levels and only 2 kingdoms (Plant & Animal)

Modern Classification System Has Seven Levels 1.Domain-Broadest levelDID 2.KINGDOM -KING 3.PHYLUM- divisions w/in the kingdom PHILLIP 4.CLASS -COME 5.ORDER-OVER 6.FAMILY -FOR 7.GENERA - (singular: genus)GOOD 8.SPECIES - most specific SPAGETTI - Species can interbreed and produce offspring

Binomial Nomenclature Binomial Nomenclature is “two-name naming” It was developed by Carolus Linnaeus It is based on Latin names (b/c Latin is not a spoken language, therefore the meanings are NOT likely to change)

Scientific Name An organism’s scientific name consists of its genus name followed by its species name Genus first & capitalized; species second & not capitalized BOTH WORDS MUST BE UNDERLINED OR IN ITALICS –Ex) Homo sapien or Homo sapien

Dichotomous Key Dichotomous Key: a set of paired statements that can be used to identify organisms. 1.Choose one statement from each pair that best fits the organism 2.After each choice, you are directed to the next set of statements you should use 3.When you have made all the choices needed, you will arrive at the name of the organism or group to which it belongs.

Dichotomous Key Example (Do not copy this slide) 1.a. Has pseudopods …… Amoeba b. No pseudopods………………go to #2 2.a. Has a flagellum…… Euglena b. No flagellum………………….go to #3 3.a. Has cillia… Paramecium

The Six Kingdoms 1.Archaebacteria Found in extreme environments; gave rise to eukaryotes; ancestors of protists 2.Eubacteria Common environments; gave rise to eukaryotic cell organelles 3.Protista “catch-all kingdom”; protozoa, algae, H2O & slime molds 4.Fungi Mushrooms, yeasts, & molds (have cell walls made of chitin) 5.Plantae Multicellular photosynthetic organisms (mosses, ferns, flowers, & trees); have cell walls made of cellulose 6.Animalia multicellular Has about 1million known species; DO NOT PHOTOSYNTHESIZE