The hymen is often torn during the first coitus (intercourse). It can also be broken by a sudden fall or jolt, insertion of a vaginal tampon, active participation in some sports like horseback riding, cycling, etc. In some women, the hymen persists even after coitus. Thus, the presence or absence of hymen is not a reliable indicator of virginity or sexual experience. The sex of the baby is determined by the father and not by the mother because in the male gametes (sperms) the sex chromosome could be either X or Y. Hence, 50 per cent of sperms carry the X chromosome while the other 50 per cent carry the Y due to which after fusion of the male and female gametes the zygote carrying XX would develop into a female baby while zygote carrying XY chromosome would develop into male.