Describe female hetergamety.

Explanation

In this method of sex determination the male produces similar type of gametes, while female produces dissimilar gametes, The heterogametic females may be of following two types.
1) ZO-ZZ: This mechanism is found in certain moths and butterflies, IN this case, females possesses one single Z chromosome and hence is heterogametic, producing two possesses two Z chromosomes and thus homogametic, producing single type of sperms, each carries single Z chromosome. The sex of the offspring depends on the kind of egg.

ii) ZW-ZZ: This system is found in certain insects ( gypsy moth) and vertebrates such as fishes, reptiles and birds. In this system the female is heterogametic and produces two types of gametes one with Z chromosome and the other with W chromosome. On the other hand, male is homogametic and produces all sperms of sam type carrying one Z chromosome. The sex of the offspring depends on the kind of egg being fertilised. The Z chromosome bearing eggs produce males, but the W chromosome bearing eggs produces females.