Oogenesis

Definition

Oogenesis is the process by which the female gametes, or ova, are produced in the ovaries. This process includes several stages such as oogonium formation, primary oocyte development, and meiosis.

5 Must Know Facts For Your Next Test

1. 1. Oogenesis begins before birth with the formation of primary oocytes during fetal development.
2. 2. Primary oocytes are arrested in prophase I of meiosis until puberty.
3. 3. Each menstrual cycle, typically one primary oocyte completes meiosis I to form a secondary oocyte and a polar body.
4. 4. The secondary oocyte is arrested in metaphase II and only completes meiosis II if fertilization occurs.
5. 5. Oogenesis results in one viable ovum and three polar bodies which eventually degenerate.

Review Questions

• What stage of meiosis are primary oocytes arrested in until puberty?
• How many viable ova result from one round of oogenesis?
• When does the secondary oocyte complete its second meiotic division?

Related terms

Spermatogenesis: The process by which male gametes, or sperm, are produced in the testes.

Meiosis: A type of cell division that reduces the chromosome number by half, crucial for sexual reproduction.

Follicle Stimulating Hormone (FSH): A hormone that stimulates the growth of ovarian follicles in females and spermatogenesis in males.