Here's why:

* Diploid cells contain two sets of chromosomes (one set from each parent).

* Gametes (sperm and egg cells) are haploid, meaning they contain only one set of chromosomes.

* Gamete-producing cells (also called germ cells or gametocytes) undergo meiosis, a special type of cell division that reduces the number of chromosomes from diploid to haploid.

So, the diploid gamete-producing cell divides through meiosis to create four haploid gametes.