trait [Fr, trace] , 1. a characteristic mode of behavior or any mannerism or physical feature that distinguishes one individual or culture from another. 2. any characteristic quality or condition that is genetically determined and inherited as part of a specific phenotype. A trait is inherited as homozygous dominant, homozygous recessive, or heterozygous in the ratio of 1:2:1 among offspring of two heterozygous parents. In medicine the term trait is used specifically to denote the heterozygous state of a recessive disorder, such as sickle cell anemia. See also dominance, gene, Mendel’s laws, recessive allele.
