Unit 1 - Classification

Whan something is grouped into different categories based on certain characteristics, it is called classification. Taxonomy is a branch of biology concerned with grouping and naming organisms. You can classify organisms using cladograms, dichotomous keys, and the three domains/six kingdom system.

A dichotomous key (also known as a single access key) a key for identification of organisms based on a seris of choices between alternative characteristics.

A cladogram is a diagram used in cladistic (a system of biological taxonomy that defines taxa uniquely by shared chararcteristics not found in ancestral groups and uses inferred evolutionary relationships to arrange taxa in a branching hierarchy such that all members of a given taxon have the same ancestors) classification to illustrate phylogentic relationships.

The three domain/six kingdom system consits of three domains include: Archaea, Bacteria, and Eukarya. These domains classifiy all living things (unicellular bacteria to a Humpback Whale). The domain Archaea includes microorganisms that are unicellular, prokaryotic (cells with no nucleus), and very similar to Bacteria but they also have some charateristics that are similar to the Eukarya domain. The Bacteria domain has unicelluar microorganisms, that are prokaryotic and have very close charateristics ith the Archaea domain. 

The Eukarya domain consits of eukaryotic cells (cells with a nucleus), this is the only domain that has multicelluar organisms. There are 4 kingdoms in this domain: the Plantea, Animalia, Protista, and Fungi. 

In this type of classifying, there are 8 levels of classification: domain, kingdom, phylum, class, order, family, genus, and species. Each lclassification level narrows the animals simlar qualities down until they are only grouped with the same aniamls (species).