Humans exhibit sexual dimorphism in many characteristics, many of which have no direct link to reproductive ability, although most of these characteristics do have a role in sexual attraction. Sex differentiation in males proceeds in a testes dependent way while female differentiation is not gonad dependent. The SRY gene is normally found on the Y chromosome and is the testis determining factor that governs male sex differentiation.
If a sperm cell carrying a Y chromosome fertilizes the female ova, the offspring will be male (XY). In humans, sperm cells normally carry either an X or a Y sex chromosome. Human males typically possess an XY combination. Karyogram of human male using Giemsa staining.
