Exemplar Problems

Question:

What is oogenesis? Give a brief account of oogenesis.

Answer:

Oogenesis: It is the process of egg (ovum) formation in females. It begins with the formation of oogonia in the ovaries during fetal development. Oogonia multiply by mitosis and develop into primary oocytes, which enter prophase I of meiosis and get arrested at this stage until puberty. At puberty, under hormonal influence, a few primary oocytes complete meiosis I during each menstrual cycle, forming a secondary oocyte and a first polar body. The secondary oocyte begins meiosis II but gets arrested at metaphase II, which is completed only if fertilization occurs.