How is polyspermy avoided in humans?

Explanation

(i) During the process of fertilization in humans, the acrosome of the sperm enters through the corona radiata and zona pellucida layers of the ovum by releasing a enzyme called hyaluronidase. whkh is called acrosomal reaction.
(ii) Once fertilization is accomplished, cortical granules from the cytoplasm of the ovum form a barrier called the fertilization membrane around the ovum. This prevents further pen~tration of other sperms. Thus polyspermy (entry of more than one sperm into an egg) is prevented.