Dominance and Recessivity

Abstract

Dominance and recessivity are not intrinsic properties of genes or alleles but describe, in diploid organisms, the pattern of occurrence of a phenotypic trait with respect to the possible combinations of two alleles. If the trait is present in the heterozygote, it is said to be dominant or semidominant, and if it is present only in one of the homozygotes, it is recessive.