Organizing Life Classification, Taxonomy & Dichotomous Key A brief review…..
Classification
CLASSIFICATION is a manmade system for grouping living organisms with similar characteristics. TAXONOMY is the branch of biology that assigns names to all the various living organisms.
Binomial Nomenclature Carolus Linnaeus ( ) developed the system which gives a two part scientific name to each kind of organism. Rana pipiens or Rana pipiens
Binomial Nomenclature Linnaeus’s system that gives each organism two names: -First word – genus; always capitalized -Second word – species; lowercase -Both words are italicized or underlined -Example: Homo sapiens (humans); if you were writing the name you would underline the words – Homo sapiens
Binomial Nomenclature Scientists agreed to use a single name for each species. Because eighteenth-century scientists understood Latin and Greek, they used those languages for scientific names. Genus – (first word) a group of closely related species Species – (second word) unique to each species within the genus
Taxonomy Categories of organisms are referred to as Taxon or TAXA. !
Background Image: Dichotomous Key special guides to help identify organisms. consists of several pairs of descriptive statements
CLASSIFICATION Linnaeus’s system of classification includes seven levels. Listed from largest to smallest
Classification Biologists place living things in the classification system based on phylogeny (evolutionary relationships, structure, development, biochemistry, and behavior.
The Six Kingdoms Organizing life in infinite varieties
Kingdom Eubacteria True bacteria: prokaryotic, microscopic, unicellular more than 10,000 species identified
Kingdom Archaebacteria Ancient bacteria found in extreme environments like salt lakes, deep ocean vents and geysers. Unicellular Prokaryotic – live in the absence of oxygen
Kingdom Protista Unicellular & multicellular some plantlike & some animallike, but are not plants, animals or fungi Eukaryote that lacks complex organ systems Amoeba, Paramecium, slime molds, giant kelp
Kingdom Protista No single trait is unique to protist Protists can be autotrophs or heterotrophs, and a few can switch between modes Some single-celled protists can develop into a nonmotile, dormant cyst during hard times
Kingdom Fungi Decomposers Unicellular or multicellular eukaryotic Heterotrophic Mushrooms, yeast
Kingdom Plantae Multicellular oxygen producers stationary eukaryotes most have cellulose cell walls Chloroplasts Mosses, ferns, flowering plants
Kingdom Animalia Multicellular consumers; most able to move no cell walls most have specialized tissues & organs Eukaryotic Sponges, worms, insects, fishes, mammals