Producing gametes with different sex chromosomes, as in the human male.
Describing the sex that produces two different kinds of gamete, which carry different sex chromosomes, and that therefore determines the sex of the offspring. In humans men are the heterogametic sex: the sperm cells carry either an X or a Y chromosome.
To the production of unlike gametes, applied especially to a male that produces two types of sperm, one containing the X chromosome, the other the Y chromosome.