Explain why fertilization is possible only within 24-48 hours after ovulation

Explain why fertilization is possible only within 24-48 hours after ovulation, despite the fact that spermatozoa retain the ability to fertilize for 72 hours.

The egg cell matures in the follicles – the nests of the ovary. Her exit from these nests is called ovulation. The female gamete – the egg retains the ability to accept sperm for one to two days after ovulation. At the end of this period, the ovum loses its ability to accept male gametes. Fertilization is the process of fusion of two germ cells – a male (sperm) with a female (egg). Therefore, fertilization is possible within 24 to 48 hours after ovulation.