When a sperm comes in contact with zona pellucida of the ovum, it prevents the entry of other sperms.

Q. After a sperm has penetrated in ovum during fertilisation, the entry of further sperms is prevented by

Q. After a sperm has penetrated an ovum, in the process of fertilization, entry of further sperms is prevented by

Q. Fill up the blanks in the following paragraph by selecting the correct option.
During copulation (coitus), semen is released by the penis into the vagina and is called (i) . The ovum released by the ovary is transported to the (ii) where (iii) takes place. During fertilisation, a sperm comes in contact with the zona pellucida layer of the ovum and induces changes in the membrane that block the entry of (iv) . The secretions of the (v) help the sperm enter into the cytoplasm of the ovum.

Q. Assertion :Polyspermy is inhibited by zona pellucida Reason: Sperm induces changes in zona pellucida

Q. Which of the following layers of the ovum undergoes changes to prevent polyspermy when sperm contacts with it?