Sex is the biological trait of an anisogamous reproducing organism in producing either male or female gametes. [1][2][3] during sexual reproduction, a male and a female gamete fuse to form a zygote, รขโ‚ฌยฆ Gender and sex - an overview | sciencedirect topics

In humans, primary sex determination occurs at fertilization and is directed by a complement of sex รขโ‚ฌยฆ