GAMETOGENESIS The making of gametes GAMETE SEX CELL

GAMETOGENESIS: The making of gametes GAMETE - SEX CELL (SPERM OR EGG) GENESIS - TO MAKE OR CREATE

Types of Gametogenesis SPERMATOGENESIS: Makes MALE sperm cells OOGENESIS: Makes the FEMALE egg cells Both processes use MEIOSIS as their type of cell division, however the results are quite different.

SPERMATOGENESIS Primary Spermatocyte 46 Where does it occur? 23 In the TESTES Secondary Spermatocytes 23 Description of Germ Cells GERM CELLS in the testes are DIPLOID (2 N, 46) just like the rest of the body cells. Initial germ cells are called PRIMARY SPERMATOCYTES What is produced? 1 round of spermatogenesis produces FOUR healthy sperm cells. Every sperm cell contains a unique combination of genes. (NO TWO ARE ALIKE!) 23 23 Spermatids Mature Sperm Cells

OOGENESIS Primary Oocyte 46 Where does it occur? In the OVARIES Secondary Oocytes Description of the Germ Cells GERM CELLS in the ovaries are DIPLOID (2 N, 46) just like the rest of the body cells. 23 23 23 X X X Initial germ cells are called PRIMARY OOCYTES What is produced? 1 round of Oogenesis produces ONE healthy egg cell (OVUM), and THREE POLAR BODIES. The polar bodies serve NO PURPOSE in the body. 3 Polar Bodies Mature Egg Cell (OVUM) 23 1 Ootid

Once gametes are formed, organisms can undergo SEXUAL REPRODUCTION and/or FERTILIZATION. Sexual Reproduction: The fusion of two gametes Fertilization: The fusion of the egg and sperm

Critical Concepts/Connections How is spermatogenesis different from oogenesis? What are three sources of genetic diversity? (clue: 2 are from meiosis and 1 is from fertilization) How are the terms sexual reproduction and fertilization different? (Why might scientists need two different terms) In the creation of a child, when is meiosis necessary and when is mitosis necessary?