How is polyspermy prevented?
Understand the Problem
The question is asking about the mechanisms that prevent polyspermy, which is the fertilization of an egg by multiple sperm cells. It seeks to understand the biological processes involved in ensuring that only one sperm fertilizes the egg.
Answer
The zona pellucida becomes impermeable upon fertilization, preventing polyspermy.
Upon fertilization, the zona pellucida surrounding the mammalian egg becomes impermeable, preventing further sperm entry. This process is triggered by the exocytosis of cortical granules.
Answer for screen readers
Upon fertilization, the zona pellucida surrounding the mammalian egg becomes impermeable, preventing further sperm entry. This process is triggered by the exocytosis of cortical granules.
More Information
Polyspermy is prevented primarily through the fast block (depolarization of the egg plasma membrane) and the cortical reaction, which involves the exocytosis of cortical granules leading to hardening of the zona pellucida.
Tips
A common mistake is assuming that preventing polyspermy relies solely on one mechanism, when both fast and slow blocks are typically involved.
Sources
- Nature Article on Polyspermy - nature.com
- BYJU'S Article on Polyspermy Prevention - byjus.com
