Chapter 18

• Binomial nomenclature


  A classification system in which a species is assigned a scientific name consisting of two parts
• Genus


  • A group of closely related species; the first part of the scientific name
• Systematics


  The science of naming and grouping organisms
• Family


  • In classification, a group of similar genera
• Order


  • In classification, a group of closely related families
• Phylum


  • In classification, a group of closely related classes
• Kingdom


  • The largest and most inclusive group in the Linnaean classification system
• Clade


  An evolutionary branch that includes a single common ancestor and all its descendants
• Derived character


  • A trait that arose in the most recent common evolutionary line and was passed on to all its descendants
• Domain


  A taxonomic category larger than a kingdom
• Domains


  • Bacteria
  • Archaea
  • Eukarya
• Bacteria are the domain of unicellular prokaryotes that have cell walls containing peptidoglycan
• Archaea are the domain of unicellular prokaryotes that have cell walls but don't contain peptidoglycan
• Eukarya is the domain consisting of all organisms that have a nucleus