AP BIOLOGY

Detailed explanation-1: -Phenotypic variation, then, is the variability in phenotypes that exists in a population. For example, people come in all shapes and sizes: height, weight, and body shape are phenotypes that vary. Hair, eye color, and the ability to roll your tongue are variable phenotypes, too.

Detailed explanation-2: -Both genetic and environmental factors can cause phenotypic variation in a population. Different alleles can confer different phenotypes, and different environments can also cause individuals to look or act differently.

Detailed explanation-3: -The prevailing model in crop science partitions the phenotypic variance into genetic (G), environmental (E) and interaction (G × E) components, plus a residual ‘error’ term. A variant of this model also accounts for maternal effects on trait expression (Galloway et al., 2009).