Question

The primary oocytes remain without any growth in human females for ......... years.

• A. 5 - 6
• B. 12 - 14
• C. 1 - 2
• D. 4 - 5

Answer 1

Answer: (B)

12 - 14

The process of formation of a mature female gamete is called oogenesis which is markedly different from spermatogenesis. Oogenesis is initiated during the embryonic development stage when a couple of million gamete mother cells (oogonia) are formed within each fetal ovary; no more oogonia are formed and added after birth. These cells start division and enter into prophase-I of the meiotic division and get temporarily arrested at that stage, called primary oocytes. Each primary oocyte then gets surrounded by a layer of granulosa cells and then called the primary follicle. A large number of these follicles degenerate during the phase from birth to puberty (a span of 12 to 14 years). Therefore, at puberty only 60,000-80,000 primary follicles are left in each ovary. Further development in primary follicles in the ovary grow them to become a fully mature Graafian follicle. These changes in the ovary are induced by changes in the levels of pituitary and ovarian hormones.