Two major functions of testis are:

•Testis produces male gametes called spermatozoa by the process called spermatogenesis.

•Testosterone are the male sex hormones secreted by the seminiferous tubules of the leydig cells, this hormone is responsible for the development of secondary male characteristics.

Two functions of ovary are:

•Ovary produces the female gametes called ova by the process of oogenesis.

•Estrogens are the female sex hormones secreted by the growing Graffian follicles and this hormone is responsible for the development of secondary female characteristics.