Biology / Unit 8: Classification and Diversity of Life
8.1 Taxonomy and Binomial Nomenclature
Notes
Taxonomy is the science of naming and classifying organisms. Carolus Linnaeus created the system we use.
- Levels from broadest to most specific: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species ("Dear King Philip Came Over For Good Soup").
- Binomial nomenclature gives each species a two-part scientific name: Genus species, such as Homo sapiens.
- The genus is capitalized; the species name is lowercase; the whole name is in italics (or underlined).
- Organisms in the same genus are more closely related than those only in the same family.
- A dichotomous key identifies organisms using a series of paired choices.
- A cladogram (phylogenetic tree) shows evolutionary relationships based on shared traits.
Practice
Which is the correct way to write the scientific name of the gray wolf?
Genus capitalized, species lowercase, both italicized.
Which pair of organisms is most closely related?
Genus is the most specific level listed, so they share the most traits.
A tool that identifies an organism by asking pairs of yes-or-no style questions (for example, "Has wings / Does not have wings") is a:
"Dichotomous" means dividing into two parts.
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