Dominance in genetics is a relationship between alleles of a gene, in which one allele masks the expression (phenotype) of another allele at the same locus. In the simplest case, where a gene exists in two allelic forms (designated A and B), three combinations of alleles (genotypes) are possible: AA, AB, and BB. If AA and BB individuals (homozygotes) show different forms of the trait (phenotype), and AB individuals (heterozygotes) show the same phenotype as AA individuals, then allele A is said to dominate or be dominant to or show dominance to allele B, and B is said to be recessive to A. If instead AB has the same phenotype as BB, B is dominant to A.
Famous quotes containing the word dominance:
“Imperialism is capitalism at that stage of development at which the dominance of monopolies and finance capitalism is established; in which the export of capital has acquired pronounced importance; in which the division of the world among the international trusts has begun, in which the division of all territories of the globe among the biggest capitalist powers has been completed.”
—Vladimir Ilyich Lenin (18701924)