Final answer:
The amount of variation in characteristics that arises from genes is quantified with a number that is referred to as heritability.
Step-by-step explanation:
The amount of variation in characteristics that arises from genes is quantified with a number that is referred to as heritability.
Heritability is a measure of how much of the variation in a trait is due to genetic factors. It is calculated by comparing the variation in a trait within a population to the genetic relatedness between individuals.
For example, if there is a high heritability for a trait like height, it means that a large proportion of the differences in height between individuals is due to genetic factors.