What is the number of sperms present in a single ejaculation of semen?

Under the influence of which hormone does spermatogenesis and oogenesis occur in vertebrates?

During the first meiotic division,into what do the primary spermatocytes differentiate?

Spermatogenesis is affected by which of the following?

Head region of the sperm contains

For normal fertility,at least ....... of the sperm in a human ejaculate must have normal shape and size,and at least ...... of them must show vigorous motility.