Observe the figure and answer the following questions:
Identify the statements which are true for oogenesis.
A. Large number of primary follicles degenerate during the phase from birth to puberty.
B. Antrum a fluid filled cavity surrounded by a new theca is seen in primary follicles.
C. At puberty only 6 × 105 - 8 × 105 primary follicles are left in each ovary.
D. Oogonia are formed in fetal ovary.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A and D only
A. Large number of primary follicles degenerate during the phase from birth to puberty. — True.
B. Antrum a fluid filled cavity surrounded by a new theca is seen in primary follicles. — False. The antrum appears in the tertiary follicle.
C. At puberty only 6 × 105 - 8 × 105 primary follicles are left in each ovary. — False. Only 60,000–80,000 (6–8 × 104) are left.
D. Oogonia are formed in fetal ovary. — True.
NCERT Extract:
Gametogenesis – “… 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 is called the primary follicle (Figure 2.7). A large number of these follicles degenerate during the phase from birth to puberty. Therefore, at puberty only 60,000-80,000 primary follicles are left in each ovary.”
