What ensures that only one sperm will fertilize an egg?

Related questions

1. What path does sperm take to fertilize an egg?
2. How much sperm does a man produce a day?
3. Where sperm is produced?
4. What should vas deferens feel like?
5. Can epididymitis cure itself?
6. Can you feel seminal vesicles?
7. How can I relax my prostate?
8. Does urine flush out sperm?
9. Can a guy pee when he's hard?
10. What is the definition of ejaculatory duct?

Tags

1. #fusing
2. #sperm
3. #polyspermy
4. #block
5. #first
6. #rapid
7. #plasma
8. #thereby
9. #fusion
10. #ensure
11. #caused
12. #membrane
13. #cases
14. #primary
15. #depolarization
16. #operate
17. #fertilizes
18. #mechanisms
19. #prevents
20. #which
21. #further