Q.60 Following statements are with reference to oogonia. Which of these is incorrect?
1. Common fate of oogonia is death by apoptosis.
2. Oogonia are able to undergo mitotic division.
3. Number of oogonia grows especially during puberty.
4. Oogonia are diploid cells.
Oogonia Characteristics: Incorrect Statement Identified
The incorrect statement about oogonia is option 3: Number of oogonia grows especially during puberty, as oogonia multiply only prenatally and most degenerate before birth.
Oogenesis Timeline
Oogonia are diploid (2n=46) female germ cells formed during fetal development (~3rd-7th month gestation), undergoing mitotic proliferation then entering meiotic arrest as primary oocytes.
Peak population (6-7 million) occurs mid-gestation; >99% undergo atresia by birth, leaving ~1-2 million arrested oocytes.
Puberty activates follicular development/recruitment from this fixed pool—no new oogonia produced.
Incorrect Statement: Option 3
Number of oogonia grows especially during puberty is false—oogonial mitosis ceases before birth; puberty increases ovulations but depletes oocyte reserve.
| Statement | Correct/Incorrect | Explanation |
|---|---|---|
| 1 | Common fate: death by apoptosis | Correct—Most (>99%) oogonia apoptose prenatally |
| 2 | Able to undergo mitotic division | Correct—Rapid prenatal proliferation via mitosis |
| 3 | Number grows during puberty | Incorrect—No oogonial mitosis postnatally |
| 4 | Diploid cells | Correct—2n=46 chromosomes before meiosis I |
Option Breakdown
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Option 1 (Correct): Atresia eliminates excess oogonia; only ~400 mature lifetime.
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Option 2 (Correct): Fetal oogonia divide mitotically to amplify germ cell pool.
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Option 3 (Incorrect): Post-birth: oogonia → primary oocytes (arrested prophase I); puberty recruits existing oocytes—no oogonial growth.
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Option 4 (Correct): Diploid until primary oocyte stage; meiosis I completes at ovulation.
Key Developmental Sequence
Fetal: PGCs → Oogonia (2n, mitotic ↑) → Primary oocytes (arrested)
Birth: ~1M oocytes remain
Puberty: FSH surge → Follicle maturation (no new oogonia)
Menopause: ~1K oocytes depleted
Distinguishes female (fixed pool) vs male (continuous) gametogenesis—crucial NEET reproductive biology concept.
