Question

How is polyspermy prevented?

Answer 1

Polyspermy:

1. When more than one sperm penetrates the egg, the condition is known as polyspermy, which can be harmful because too many centrosomes impair development.
2. However, in other species, more than one sperm can penetrate the egg without appearing to harm the viability of the zygote.
3. A single sperm is required to fertilize an egg.
4. Mammalian eggs have a barrier called the zona pellucida that surrounds them.
5. Upon fertilization, this structure becomes impermeable, preventing more sperm from entering the egg.
6. The exocytosis of cortical granules causes structural changes in the zona after fertilization.
7. To prevent the sterility effects associated with deadly genome imbalance and chromosome segregation problems during zygote and embryo development, a block to polyspermy must be established after the successful fertilization of the egg cell.