| A | B |
|---|
| taxonomy | scientist classify organisms and assign each organism a universally accepted name |
| binomial nomenclature | each species is assigned a two-part name; scientific name is always written in italics |
| genus | a group of closely related species |
| taxon | a level in the taxonomic nomenclature |
| family | a larger group category |
| order | a broad taxonomic category made up of similar families |
| phylum | several different classes |
| kingdom | the largest and most inclusive of taxonomic categories |
| phylogeny | evolutionary relationships among organisms |
| evolutionary classification | strategy of grouping organisms together based on their evolutionary history |
| derived character | characteristics that appear in recent parts of a lineage but not in its older members |
| cladogram | a diagram that shows the evolutionary relationships among a group of organisms |
| molecular clock | a model that uses DNA comparisons to estimate the length of time that two species have been evolving independently |
| domain | a more inclusive category that any other-larger than a kingdom |
| bacteria | unicellular and prokaryotic |
| eubacteria | ecologically diverse, ranging from free-living soil organisms to deadly parasites |
| archae | unicellular and prokaryotic; live in the most extreme environments |
| archaebacteria | corresponds to the category archae |
| eukarya | consists of all organisms that have a nucleus; organized into four kingdoms |
| protista | composed of eukaryotic organisms that cannot be classified as animals, plants, or fungi |
| fungi | heterotrophs; most feed on dead or decaying organic matter |
| plantae | multicellular organisms that are photosynthetic autotrophs |
| animalia | multicellular and heterotrophic; the cells of animals do not have cell walls |
