V

Variance component: A contribution to the phenotypic variance due to a specific kind of variation. It includes environmental, additive, dominance, and interaction variances.
Variety: A number of different types of things.
Variant: A genetic concept indicating one type (genotype) among many.
Variability: Having much variation or diversity.
Vascular plants: Division of plants with vascular tissues, which function in transporting fluids.
Vertical descent: The evolution of species by a branching pattern. Also known as vertical evolution.
Vertical inheritance: The transmission of traits from parent to offspring. Also known as vertical transmission.
Virulence: The degree of pathogenicity of a parasite.
Vulnerable: Capable or susceptible to being wounded or hurt. Open to assault.