(N/A) Heterogamety is a condition in which an individual produces two different types of gametes with respect to sex chromosomes.
$1$. Male Heterogamety: In this mechanism,the male produces two different types of gametes. For example,in the $XX-XY$ type (seen in humans and Drosophila),males produce $50\%$ of gametes with an $X$ chromosome and $50\%$ with a $Y$ chromosome. In the $XX-XO$ type (seen in grasshoppers),males produce $50\%$ of gametes with an $X$ chromosome and $50\%$ without any sex chromosome $(O)$.
$2$. Female Heterogamety: In this mechanism,the female produces two different types of gametes. For example,in the $ZZ-ZW$ type (seen in birds),females produce $50\%$ of gametes with a $Z$ chromosome and $50\%$ with a $W$ chromosome. In the $ZZ-ZO$ type,females produce $50\%$ of gametes with a $Z$ chromosome and $50\%$ without any sex chromosome $(O)$.