question_answer 79)

  How does fertilization take place? Fertilisation occurs once in a month. Comment.

Answer:

                  Feminization in human beings the sperms made in the testis of males are introduced into the vagina of the woman through penis during copulation or mating. The sperms are highly active and mobile and thus move up through cervix into the uterus. From uterus, sperms pass into the oviducts. The oviduct contains an ovum released by the ovary during ovulation. Millions of sperms are released into the vagina at one time, but only one sperm fuses with the ovum in the oviduct to form a zygote. This is called fertilization. Fertilization can occur only once in a month because the ovary releases just one mature egg every month during a menstrual cycle (around 14th day).