Meiosis, the process of cell division that produces gametes (sex cells), occurs in specific structures or organs within animals, depending on the sex:

Males:

* Testes: These are the male reproductive organs where spermatogenesis, the process of forming sperm cells, takes place. Within the testes, specific cells called spermatogonia undergo meiosis to produce sperm.

Females:

* Ovaries: These are the female reproductive organs where oogenesis, the process of forming egg cells, takes place. Within the ovaries, specific cells called oogonia undergo meiosis to produce eggs.

So, in summary:

* Male gamete formation (spermatogenesis) occurs in the testes.

* Female gamete formation (oogenesis) occurs in the ovaries.