Egg and Sperm Formations in Animals Animation

Inside the ovaries of a female animal are diploid germ cells called oogonia. An oogonium grows to become a primary oocyte. This large cell is still diploid. Meiosis I followed by unequal cytoplasmic division produces one large secondary oocyte and a smaller polar body. Both are haploid. Completion of meiosis and a second round of unequal cytoplasmic division produces one large secondary oocyte and three smaller polar bodies. The secondary oocyte will function as a gamete and is also called an ovum, or egg. The polar bodies will degenerate. Inside the testes of a male animal are diploid germ cells called spermatogonia. One of these cells grows to become a primary spermatocyte. This large cell is still diploid. Meiosis I and cytoplasmic division produce two haploid secondary spermatocytes. Meiosis II and cytoplasmic division produce four spermatids. These cells undergo changes in form to become sperm, the mature male gametes.

Add To

You must login to add videos to your playlists.