A gene is said to be dominant to one of its alleles if it suppresses the phenotypic effect of that (recessive) allele when the two are together. For example, if brown eyes are dominant to blue, only individuals with two blue-eyed genes (homozygous recessive) would actually have blue eyes; those with one blue and one brown gene (heterozygotes) would be indistinguishable from those with two brown genes (homozygous dominant). Dominance may be incomplete, in which case heterozygotes have an intermediate phenotype. The opposite of dominant is recessive. Dominance/recessiveness is a property of a phenotypic effect, not of a gene as such; thus a gene may be dominant in one of its phenotypic effects and recessive in another.
