Classifying Organisms Ch.1 Sect 2

Classifying Living Things Aristotle was one of the first people to classify organisms. He classified organisms into 2 groups: plants or animals. Classification: putting organisms into groups Taxonomy: the science of classifying, naming, or describing organisms based on similar characteristics. Classifying Living Things

7 Levels of Classification Kingdom Phylum Class Order Family Genus Species King Philip Came Over For Grape Soda Carolus Linnaeus classified organisms based on similar structures. Placed organisms into 2 main group called Kingdoms 7 Levels of Classification

Robert Whittaker later proposed 5 kingdom system on classifying organisms. If a new organism is discovered and does not fit any other kingdom, scientists will start a new kingdom. 6 Kingdoms: Animalia- ex. Dog Plantae – ex. sunflower Archaebacteria- methane making bacteria. Eubacteria – ex. strep Fungi - mushroom Protista – last kingdom discovered Determining Kingdoms

Determining Domains Classification system is not complete. Systematics- current classification system being used. (uses all characteristics to place organisms in the correct kingdom). Kingdoms are now placed into 3 domains: 1. Bacteria 2. Archaea 3. Eukarya Determining Domains

Scientific Names All organisms have a common name and scientific name. The scientific name of an organism consists of the genus and species. Binomial Nomenclature- is the naming system used to name organisms. Species- a group of organisms that have similar traits and are able to produce a fertile offspring. Genus- is a group of similar species. Scientific Names

Dichotomous Keys- a series of descriptions arranged in pairs that leads the user to the identification of an unknown organism. Cladograms – a branched diagram that shows the relationships among organisms including common ancestors. Each branch in a cladogram follows a new characteristic. Classification Tools