heterogametic sex

views updated May 21 2018

heterogametic sex The sex that has sex chromosomes that differ in morphology (e.g. XY), and that therefore produces two different kinds of gametes with respect to the sex chromosomes. The term may also refer to the possession of an unpaired sex chromosome (a single X-chromosome). In mammals and most other animals, the male is the heterogametic sex, usually with equal numbers of different gametes X and Y, although some men, for example, have XXY or even XXXY. In birds, reptiles, some fish and amphibians, and Lepidoptera, the female is the heterogametic sex.

heterogametic sex

views updated May 29 2018

heterogametic sex The sex that is determined by possession of two dissimilar sex chromosomes (e.g. XY). In humans and many other mammals this is the male sex. The heterogametic sex produces reproductive cells (gametes) of two kinds, half containing an X chromosome and half a Y chromosome. Compare homogametic sex.

heterogametic sex

views updated May 21 2018

heterogametic sex The sex that has sex chromosomes that differ in morphology (e.g. XY), and therefore produces two different kinds of gametes with respect to the sex chromosomes. The term may also refer to the possession of an unpaired sex chromosome (a single X-chromosome). In mammals and most other animals, the male is the heterogametic sex, usually with equal numbers of different gametes X and Y, although some men, for example, have XXY or even XXXY. In birds, reptiles, some fish and amphibians, and Lepidoptera, the female is the heterogametic sex.