Cells that exit meiosis are not immediately capable of fertilization. After meiosis, the resulting haploid cells (gametes) undergo a process called maturation or differentiation before becoming fertilization-competent. This maturation process involves additional cellular and biochemical changes to prepare the gametes for their roles in fertilization.

For example, in the case of sperm cells, maturation occurs in the epididymis, where they gain the ability to move (become motile), undergo structural changes in their heads, and acquire the ability to fertilize an egg. Similarly, in the case of eggs, maturation involves changes such as the completion of meiosis, acquiring the capacity to bind sperm, and undergoing biochemical modifications that support fertilization and early embryonic development.

The maturation process can vary in duration depending on the species and type of gamete. In some cases, it can take several hours or days, while in others, it may occur over a longer period. Once the maturation process is complete, the gametes become fully competent for fertilization and are capable of participating in the formation of a zygote, the first cell of a new organism.