| A | B |
|---|
| taxonomy | the discipline of classifying organisms and assigning each organism a universally accepted name |
| binomial nomenclature | a classification system in which each species is assigned a two-part scientific name |
| genus | a group of closely related species, first part of the scientific name in binomial nomenclature |
| taxon | a group or level of organization into which organisms are classified |
| family | a group of genera that share many characteristics |
| order | a group of similar families |
| class | a group of similar orders |
| phylum | a group of closely related classes |
| kingdom | the largest taxonomic group, consisting of closely related phyla |
| evolutionary classification | a method of grouping organisms together according to their evolutionary history |
| derived character | a characteristic that appears 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 | the most inclusive taxonomic category; larger than a kingdom |
| Bacteria | a domain of unicellular prokaryotes that have cell walls containing peptidoglycans |
| Eubacteria | a kingdom of unicellular prokaryotes whose cell walls are made up of peptidoglycan |
| Archaea | a domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan |
| Archaebacteria | a kingdom of unicellular prokaryotes whose cell walls do not contain peptidoglycan |
| Eukarya | a domain of all organisms whose cells have nuclei, including protists, plants, fungi and animals |
| Protista | a kingdom composed of eukaryotes that are not classified as plants, animals or fungi |
| Fungi | a kingdom composed of heterotrophs; man y obtain energy and nutrients from dead organic matter |
| Plantae | a kingdom of multicellular photosynthetic autotrophs that have cell walls containing cellulose |
| Animalia | a kingdom of multicellular eukaryotic heterotrophs whose cells do not have cell walls |
