Gametogenesis sex cell beginning

1. Gametogenesissex cell beginning Gametogenesis – gamete formation where daughter cells, or gametes, are produced at the end of meiosis II resulting in the production of sperm and egg.

2. 2 Types of Gamete Formation Oogenesis – the process of female gamete production in animals Spermatogenesis – the process of male gamete production in animals

3. Spermatogenesis pictures

4. Spermatogenesis process • Spermatogenesis begins with diploid germ cells called spermatogonia that grow and develop into a primary spermatocyte. • During meiosis I, one spermatigonium divides into two cells called secondary spermatocytes. • Secondary spermatocytes undergo meiosis II to form spermatids, which develop into sperm. • In the end, from 1 parent spermatigonium 4 sperm cells are produced.

5. Spermatogenesis notes • Spermatogenesis occurs inside testes • Within testes spermatogenesis occurs in walls of seminiferous tubules • Mature sperm are released into lumen of seminiferous tubules. • Spermatigonia & Primary spermatocytes are 2n • Secondary spermatocytes are 1n • Spermatids and sperm are 1n

6. Oogenesis pictures

7. Oogenesis process • Oogenesis begins with a diploid cell called an oogonium. • After growth and development, one oogonium forms one primary oocyte. • Meiosis I produces a secondary oocyte and one polar body (due to unequal division of the cytoplasm). • Meiosis II in the secondary oocyte produces an egg and polar body. Meiosis II in first polar body produces 2 polar bodies. • The egg survives, while all the polar bodies die. • Only one functional egg cell comes from this process, as the unequal division of the cytoplasm makes the egg cell big (needs extra nutrients).

8. Oogenesis notes • Oogenesis occurs inside the ovary • Within testes oogenesis occurs in a follicle • Eggs are released into oviduct • Oogonium & Primary oocytes are 2n • Secondary oocytes are 1n • Polar bodies and eggs are 1n

9. Oogenesis vs. Spermatogenesis