Human Reproduction Question 45
45. What happens during fertilisation in humans after many sperms reach close to the ovum?
[2011M]
(a) Secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida
(b) All sperms except the one nearest to the ovum lose their tails
(c) Cells of corona radiata trap all the sperms except one
(d) Only two sperms nearest the ovum penetrate zona pellucida
Show Answer
Answer : a
Hints & Solutions
(a) During fertilisation in humans, many sperms reach close to the ovum. As sperm comes in contact with the zona pellucida layer of the ovum it induces changes in the membrane that blocks the entry of additional sperm. The secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida. The zona pellucida supports communication between oocytes and follicle cells during oogenesis protects oocytes, eggs, and embryos during development, and regulates interactions between ovulated eggs and free-swimming sperm during and following fertilization.
