the cortical reaction- lqc 2b

Question 1

What is the purpose of the cortical reaction?

Answer 1

To harden the zona pellucida to prevent polyspermy (more than one sperm entering an ovum)

Question 2

process of the cortical reaction

Answer 2

1. Genetic material from the sperm head enters the ovum
2. Cortical granules in the cytoplasm of the ovum move
   towards and fuse with egg cell surface membrane, releasing enzymes by
   exocytosis into the zona pellucida
3. The zona pellucida hardens/ thickens which prevents polyspermy
4. There is a change in charge across egg cell membrane.