1. Polyspermous fertilization occurs when multiple sperm cells merge with the egg during fertilization.
多精子受精发生在多个精子与卵子结合时。

2. In some species, such as sea urchins, polyspermous fertilization is a normal part of the reproductive process.
在某些物种中，如海胆，多精子受精是繁殖过程的正常部分。