Question

The changes in the membrane of the ovum and certain cortical reactions prevent polyspermy. so what are these cortical reactions?

Answer 1

The reaction that takes place in the egg membrane after the sperm gets fused inside the egg is known as cortical reaction. This reaction transforms the egg membrane (zona pellucida) into a hard covering which prevents entry of any other sperms inside the egg. Hence, cortical reaction prevents polyspermy.