Part 3: Gametogenesis — Spermatogenesis, Oogenesis & Hormonal Control

Part 3: Gametogenesis — Spermatogenesis, Oogenesis & Hormonal Control

Q1. Spermatogenesis occurs in:

a) Vas deferens
b) Epididymis
c) Seminiferous tubules
d) Prostate

Answer: c) Seminiferous tubules
Explanation:

• (c) Correct. Spermatogenesis starts in seminiferous tubules.
• Others are storage/transport glands, not production sites.

Q2. Which hormone directly stimulates Leydig cells to secrete testosterone?

a) FSH
b) LH
c) Inhibin
d) Prolactin

Answer: b) LH
Explanation:

• (b) Correct. LH (also called ICSH in males) stimulates Leydig cells.
• FSH → acts on Sertoli cells.
• Inhibin → feedback, not stimulation.
• Prolactin → minor supportive role, not direct.

Q3. Which hormone regulates spermatogenesis through Sertoli cells?

a) LH
b) FSH
c) Oxytocin
d) Cortisol

Answer: b) FSH
Explanation:

• (b) Correct. FSH acts on Sertoli cells → support spermatogenesis.
• LH → Leydig, not Sertoli.
• Oxytocin & cortisol → unrelated.

Q4. Spermatogonia are:

a) Diploid stem cells
b) Haploid cells
c) Primary spermatocytes
d) Spermatozoa

Answer: a) Diploid stem cells
Explanation:

• (a) Correct. Spermatogonia are diploid (2n) stem cells.
• Others are later stages.

Q5. Each primary spermatocyte undergoes meiosis I to form:

a) Two spermatogonia
b) Two secondary spermatocytes
c) Four spermatids
d) Two spermatozoa

Answer: b) Two secondary spermatocytes
Explanation:

• (b) Correct. Primary spermatocyte (2n) → meiosis I → 2 haploid secondary spermatocytes.

Q6. Each secondary spermatocyte after meiosis II produces:

a) Two spermatozoa
b) Two spermatids
c) One spermatid
d) Four spermatids

Answer: b) Two spermatids
Explanation:

• (b) Correct. Each secondary spermatocyte divides → 2 spermatids (haploid).

Q7. From one primary spermatocyte, how many spermatozoa are ultimately formed?

a) 2
b) 4
c) 8
d) 16

Answer: b) 4
Explanation:

• (b) Correct. One primary spermatocyte → 2 secondary spermatocytes → 4 spermatids → 4 spermatozoa.

Q8. The process of transformation of spermatids into spermatozoa is called:

a) Spermatogenesis
b) Spermiogenesis
c) Spermiation
d) Fertilization

Answer: b) Spermiogenesis
Explanation:

• (b) Correct. Morphological maturation of spermatids into spermatozoa.

Q9. Release of mature spermatozoa into the lumen of seminiferous tubules is called:

a) Spermiogenesis
b) Spermiation
c) Spermatogenesis
d) Capacitation

Answer: b) Spermiation
Explanation:

• (b) Correct. Spermiation = release of sperm into lumen from Sertoli cells.

Q10. Oogenesis in females begins:

a) At birth
b) At puberty
c) During embryonic development
d) At menopause

Answer: c) During embryonic development
Explanation:

• (c) Correct. Oogonia form during fetal life; arrested at prophase I until puberty.

Q11. At puberty, the primary oocyte completes:

a) Meiosis I
b) Meiosis II
c) Mitosis
d) Fertilization

Answer: a) Meiosis I
Explanation:

• (a) Correct. Primary oocyte resumes meiosis I at puberty → forms secondary oocyte.

Q12. The secondary oocyte is arrested at which stage until fertilization?

a) Prophase I
b) Metaphase I
c) Metaphase II
d) Anaphase II

Answer: c) Metaphase II
Explanation:

• (c) Correct. Secondary oocyte arrested at metaphase II; completes only if fertilized.

Q13. One primary oocyte forms:

a) Four ova
b) Two ova
c) One ovum + polar bodies
d) Four polar bodies

Answer: c) One ovum + polar bodies
Explanation:

• (c) Correct. Asymmetric division → one large ovum + 2–3 small polar bodies.

Q14. Polar bodies are formed during:

a) Spermatogenesis
b) Oogenesis
c) Both
d) Neither

Answer: b) Oogenesis
Explanation:

• (b) Correct. Polar bodies form due to unequal cytokinesis in oogenesis.

Q15. The first polar body is formed after completion of:

a) Mitosis
b) Meiosis I
c) Meiosis II
d) Fertilization

Answer: b) Meiosis I
Explanation:

• (b) Correct. Meiosis I of primary oocyte → secondary oocyte + first polar body.

Q16. The second polar body is formed after:

a) Fertilization
b) Puberty
c) Ovulation
d) Implantation

Answer: a) Fertilization
Explanation:

• (a) Correct. Meiosis II completes only upon sperm entry → second polar body.

Q17. LH surge in mid-cycle is responsible for:

a) Follicle development
b) Ovulation
c) Endometrial proliferation
d) Corpus luteum regression

Answer: b) Ovulation
Explanation:

• (b) Correct. LH surge triggers rupture of Graafian follicle → ovulation.

Q18. Which hormone inhibits FSH secretion?

a) Progesterone
b) Estrogen
c) Inhibin
d) Oxytocin

Answer: c) Inhibin
Explanation:

• (c) Correct. Inhibin (from Sertoli/granulosa cells) → negative feedback on FSH.

Q19. Which hormone maintains endometrium after ovulation?

a) Estrogen
b) Progesterone
c) LH
d) FSH

Answer: b) Progesterone
Explanation:

• (b) Correct. Progesterone from corpus luteum prepares & maintains endometrium.

Q20. Estrogen is secreted by:

a) Corpus luteum
b) Granulosa cells of growing follicle
c) Sertoli cells
d) Leydig cells

Answer: b) Granulosa cells of growing follicle
Explanation:

• (b) Correct. Granulosa cells convert androgens to estrogen.

Q21. Which is NOT true about spermatogenesis?

a) Starts at puberty
b) Continuous throughout life
c) Produces one sperm from each spermatogonium
d) Regulated by FSH and testosterone

Answer: c) Produces one sperm from each spermatogonium
Explanation:

• (c) Incorrect. Each spermatogonium can produce many sperm; one primary spermatocyte forms 4 sperm.

Q22. During oogenesis, when is the primary oocyte arrested in prophase I?

a) At fertilization
b) At birth
c) At puberty
d) At ovulation

Answer: b) At birth
Explanation:

• (b) Correct. All primary oocytes are arrested in prophase I before birth.

Q23. Capacitation of sperm occurs in:

a) Testis
b) Epididymis
c) Female genital tract
d) Prostate

Answer: c) Female genital tract
Explanation:

• (c) Correct. Capacitation = physiological changes enabling fertilization, occurs in female tract.

Q24. The main function of testosterone in spermatogenesis is to:

a) Trigger spermiogenesis directly
b) Stimulate Sertoli cells to support meiosis
c) Maintain epididymal storage
d) Promote uterine lining

Answer: b) Stimulate Sertoli cells to support meiosis
Explanation:

• (b) Correct. Testosterone + FSH act via Sertoli cells for meiosis.

Q25. In females, FSH primarily stimulates:

a) Ovulation
b) Growth of ovarian follicles
c) Progesterone secretion
d) Uterine contractions

Answer: b) Growth of ovarian follicles
Explanation:

• (b) Correct. FSH promotes follicular growth, granulosa proliferation.

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