In the second process(?!)

In the second process, the sperm enters the egg, and the zygote is formed.

It’s difficult to imagine more than one process here. I think you mean:

  • In the second stage of the process, the sperm enters the egg, and the zygote is formed.

In English a process can occasionally be broken down into sub-processes, but normally we talk about these as stages. Indonesians often make the same mistake with menu and items on a menu:

  • The second menu is ayam lalapan.
  • The second item on the menu is ayam lalapan.