The Linnaean ranks, binomial names, the three-domain system and reading evolutionary trees.
What you will learn
- Put the classification ranks in order
- Use binomial names to judge how closely related organisms are
- Name the three domains
- Read an evolutionary tree for common ancestors and times
Ranks and names
Linnaeus sorted living things by their structure into ranks, from largest to smallest:
- kingdom, phylum, class, order, family, genus, species
Each organism has a two-part binomial name: the genus (capital letter) then the species, in italics. The lion is Panthera leo and the tiger is Panthera tigris: same genus, so closely related.
The more ranks two organisms share, the more closely related they are.
The first word is the genus, not the species.
The rest of this lesson and its 10 practice questions are locked.
In this lesson
- Ranks and names
- Three domains
- Evolutionary trees
10 practice questions, marked as you go; about 20 minutes in all.
Key terms
Genus, Species, Evolutionary tree, Common ancestor
In this unit: Inheritance, variation and evolution
Meiosis and DNA, Punnett squares and family trees, inherited disorders and embryo screening, natural selection, selective breeding, genetic engineering and cloning, and classification.