Spermatogenesis MCQs With Answer

Spermatogenesis MCQs With Answer

This concise guide helps B. Pharm students master spermatogenesis through targeted multiple-choice questions. Covering cellular stages from spermatogonia to spermatozoa, hormonal regulation (FSH, LH, testosterone), Sertoli and Leydig cell functions, meiosis, spermiogenesis, and clinical correlations like azoospermia, temperature effects, and drug impacts, these MCQs emphasize mechanisms, histology, and pharmacological influences. Ideal for exam revision and practical understanding, the set reinforces key terms such as seminiferous epithelium cycle, blood-testis barrier, acrosome reaction, capacitation, inhibin B, and assisted reproduction concepts. Clear explanations and focused items make complex topics accessible for pharmacy students. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the primary site of spermatogenesis in the male testis?

  • Interstitial tissue
  • Seminiferous tubules
  • Epididymis
  • Vas deferens

Correct Answer: Seminiferous tubules

Q2. Which cell type provides structural and nutritional support to developing germ cells during spermatogenesis?

  • Leydig cells
  • Sertoli cells
  • Peritubular myoid cells
  • Germinal epithelium

Correct Answer: Sertoli cells

Q3. Which hormone primarily stimulates Leydig cells to produce testosterone?

  • FSH (Follicle-stimulating hormone)
  • Prolactin
  • LH (Luteinizing hormone)
  • Inhibin

Correct Answer: LH (Luteinizing hormone)

Q4. During which phase do primary spermatocytes complete the first meiotic division?

  • Spermiogenesis
  • Spermatogonial mitosis
  • Meiosis I
  • Meiosis II

Correct Answer: Meiosis I

Q5. What is the name of the final differentiation process where spermatids become motile spermatozoa?

  • Spermatocytogenesis
  • Spermiogenesis
  • Spermatogonial renewal
  • Spermatid proliferation

Correct Answer: Spermiogenesis

Q6. Which structure in sperm contains enzymes necessary for penetration of the zona pellucida?

  • Midpiece
  • Acrosome
  • Flagellum
  • Mitochondrial sheath

Correct Answer: Acrosome

Q7. What is the role of the blood-testis barrier formed by Sertoli cells?

  • Transport testosterone to bloodstream
  • Separate germ cells from immune system and maintain microenvironment
  • Produce sperm plasma membrane components
  • Stimulate Leydig cell proliferation

Correct Answer: Separate germ cells from immune system and maintain microenvironment

Q8. Which of these events characterizes spermatogonial stem cell self-renewal?

  • Production of primary spermatocytes directly
  • Symmetric mitotic divisions producing two stem cells
  • Entry into meiosis
  • Transformation into Sertoli cells

Correct Answer: Symmetric mitotic divisions producing two stem cells

Q9. In humans, approximately how long does the entire process of spermatogenesis take?

  • 7 days
  • 30 days
  • 64–74 days
  • 180 days

Correct Answer: 64–74 days

Q10. Which marker produced by Sertoli cells is used clinically to assess spermatogenic function?

  • Prostate-specific antigen (PSA)
  • Inhibin B
  • Testosterone binding globulin
  • Lactate dehydrogenase

Correct Answer: Inhibin B

Q11. Which sperm structure contains a 9+2 microtubule arrangement essential for motility?

  • Acrosome
  • Axoneme of the flagellum
  • Midpiece mitochondria
  • Nuclear chromatin

Correct Answer: Axoneme of the flagellum

Q12. Which cell type secretes anti-Müllerian hormone (AMH) during early testicular development?

  • Leydig cells
  • Sertoli cells
  • Spermatogonia
  • Peritubular myoid cells

Correct Answer: Sertoli cells

Q13. Which statement best describes the genetic change during meiosis in spermatogenesis?

  • Chromosome number doubles
  • Diploid to haploid transition with homologous recombination in meiosis I
  • Haploid cells fuse to form diploid spermatocytes
  • No genetic recombination occurs

Correct Answer: Diploid to haploid transition with homologous recombination in meiosis I

Q14. Which of the following impairs spermatogenesis by increasing testicular temperature?

  • Cryptorchidism
  • Cold baths
  • High-altitude exposure
  • Caloric restriction

Correct Answer: Cryptorchidism

Q15. What is the primary pharmacological effect of exogenous anabolic-androgenic steroids on spermatogenesis?

  • Increase FSH and stimulate spermatogenesis
  • Directly enhance Sertoli cell function
  • Suppress gonadotropins via negative feedback, reducing spermatogenesis
  • Stimulate Leydig cell proliferation and increase sperm count

Correct Answer: Suppress gonadotropins via negative feedback, reducing spermatogenesis

Q16. Which part of the sperm is rich in mitochondria supplying ATP for motility?

  • Head
  • Neck
  • Midpiece
  • Acrosome

Correct Answer: Midpiece

Q17. In the seminiferous epithelium cycle, what is the functional significance of synchronized waves of maturation?

  • Ensure that all sperm are released simultaneously only once per year
  • Permit continuous and overlapping production of spermatozoa for steady output
  • Allow spermatogonia to become Sertoli cells periodically
  • Prevent entry of hormones into seminiferous tubules

Correct Answer: Permit continuous and overlapping production of spermatozoa for steady output

Q18. Which laboratory parameter defines oligospermia according to WHO reference limits?

  • Sperm concentration <15 million/mL
  • Sperm concentration <5 million/mL
  • Total sperm count <200 million per ejaculate
  • Progressive motility <80%

Correct Answer: Sperm concentration <15 million/mL

Q19. What is spermiation?

  • Meiotic division of spermatocytes
  • Release of mature spermatozoa from Sertoli cells into lumen
  • Fusion of sperm with oocyte
  • Proliferation of spermatogonia

Correct Answer: Release of mature spermatozoa from Sertoli cells into lumen

Q20. Which molecule produced by Sertoli cells provides paracrine inhibition of FSH secretion?

  • Inhibin B
  • Activin
  • Androgen-binding protein
  • Estradiol

Correct Answer: Inhibin B

Q21. Which drug class is most likely to cause long-term impairment of spermatogenesis due to gonadotoxicity?

  • Antihistamines
  • Chemotherapeutic alkylating agents
  • Beta-blockers
  • Low-dose aspirin

Correct Answer: Chemotherapeutic alkylating agents

Q22. During capacitation in the female reproductive tract, what major change occurs in sperm?

  • DNA replication
  • Removal of cholesterol from the plasma membrane increasing membrane fluidity
  • Spermatid elongation
  • Sertoli cell interaction

Correct Answer: Removal of cholesterol from the plasma membrane increasing membrane fluidity

Q23. Which protein binds testosterone in the seminiferous tubules and concentrates it near developing germ cells?

  • Albumin
  • Androgen-binding protein (ABP)
  • Sex hormone-binding globulin (SHBG)
  • Transferrin

Correct Answer: Androgen-binding protein (ABP)

Q24. In which cellular compartment does chromatin condense and histones largely replaced by protamines?

  • Primary spermatocyte nucleus
  • Spermatid nucleus during spermiogenesis
  • Sertoli cell nucleus
  • Leydig cell cytoplasm

Correct Answer: Spermatid nucleus during spermiogenesis

Q25. What is the effect of FSH on spermatogenesis?

  • Stimulates Leydig cells to make testosterone
  • Acts directly on Sertoli cells to promote spermatogenic support
  • Inhibits spermatogonial mitosis
  • Causes Sertoli cell apoptosis

Correct Answer: Acts directly on Sertoli cells to promote spermatogenic support

Q26. Which condition is characterized by absence of sperm in ejaculate?

  • Oligospermia
  • Azoospermia
  • Asthenozoospermia
  • Teratozoospermia

Correct Answer: Azoospermia

Q27. Which vitamin is particularly important for normal spermatogenesis and sperm DNA integrity?

  • Vitamin C
  • Vitamin A (retinoic acid)
  • Vitamin D
  • Vitamin K

Correct Answer: Vitamin A (retinoic acid)

Q28. What role do Leydig cells play in the testis?

  • Form blood-testis barrier
  • Secrete testosterone under LH stimulation
  • Phagocytose defective sperm
  • Produce inhibin B

Correct Answer: Secrete testosterone under LH stimulation

Q29. Which change in semen analysis indicates asthenozoospermia?

  • Low sperm concentration
  • Poor sperm motility
  • High leukocyte count
  • Abnormal sperm morphology

Correct Answer: Poor sperm motility

Q30. What is the primary event of the acrosome reaction?

  • Fusion of sperm plasma membrane with oocyte membrane
  • Release of hydrolytic enzymes from the acrosome to penetrate zona pellucida
  • Completion of meiosis II in sperm
  • Detachment of tail from midpiece

Correct Answer: Release of hydrolytic enzymes from the acrosome to penetrate zona pellucida

Q31. Which factor can be used as a pharmacological target to reversibly suppress spermatogenesis in male contraception research?

  • Inhibition of mitochondrial ATP synthesis in sperm
  • GnRH analogs to suppress gonadotropin release
  • Blocking acrosome formation in mature sperm
  • Stimulating inhibin B production drastically

Correct Answer: GnRH analogs to suppress gonadotropin release

Q32. Which seminiferous epithelium cell junction is critical for maintaining the blood-testis barrier?

  • Gap junctions between Leydig cells
  • Tight junctions between adjacent Sertoli cells
  • Desmosomes between sperm heads
  • Hemidesmosomes in epididymis

Correct Answer: Tight junctions between adjacent Sertoli cells

Q33. Which of the following is a direct clinical consequence of varicocele on spermatogenesis?

  • Increased androgen production improving fertility
  • Testicular hyperthermia leading to reduced sperm quality
  • Enhanced blood-testis barrier function
  • Decreased testicular blood flow causing hypoxia but improving sperm motility

Correct Answer: Testicular hyperthermia leading to reduced sperm quality

Q34. What distinguishes primary from secondary hypogonadism in male infertility?

  • Primary: pituitary problem; Secondary: testicular failure
  • Primary: testicular failure with high gonadotropins; Secondary: hypothalamic-pituitary failure with low gonadotropins
  • No hormonal differences
  • Primary always reversible; Secondary is permanent

Correct Answer: Primary: testicular failure with high gonadotropins; Secondary: hypothalamic-pituitary failure with low gonadotropins

Q35. Which process reduces DNA content from diploid to haploid during spermatogenesis?

  • Mitosis of spermatogonia
  • Meiosis
  • Spermiation
  • Capacitation

Correct Answer: Meiosis

Q36. Which of these proteins is not typically associated with sperm chromatin packaging?

  • Protamines
  • Histones (largely replaced)
  • Actin filaments
  • Transition proteins

Correct Answer: Actin filaments

Q37. Which epididymal function is essential before sperm gain fertilizing capacity?

  • DNA replication
  • Maturation involving membrane remodeling and acquisition of motility
  • Sertoli cell support
  • Testosterone production

Correct Answer: Maturation involving membrane remodeling and acquisition of motility

Q38. Which hormone level is expected to be elevated in primary testicular failure?

  • Testosterone
  • LH and FSH
  • Prolactin only
  • Inhibin B

Correct Answer: LH and FSH

Q39. Which structure anchors developing spermatids to Sertoli cells during differentiation?

  • Intercellular bridges and ectoplasmic specializations
  • Basement membrane hemidesmosomes
  • Acrosomal granules
  • Gap junctions with Leydig cells

Correct Answer: Intercellular bridges and ectoplasmic specializations

Q40. Which diagnostic test differentiates obstructive from non-obstructive azoospermia?

  • Serum FSH and testicular volume assessment
  • Urine culture
  • Prostate ultrasound only
  • Vaginal pH measurement

Correct Answer: Serum FSH and testicular volume assessment

Q41. Which ion flux change in sperm membrane is crucial to trigger hyperactivated motility?

  • Decreased intracellular calcium
  • Increased intracellular calcium
  • Increased intracellular chloride only
  • Reduced intracellular sodium exclusively

Correct Answer: Increased intracellular calcium

Q42. Which contraceptive approach targets spermatogenesis directly in males?

  • Inhibitors of acrosome reaction in females
  • Testosterone-progestin combinations to suppress gonadotropins
  • Barrier methods like condoms
  • Vasodilators

Correct Answer: Testosterone-progestin combinations to suppress gonadotropins

Q43. Which enzyme defect in sperm is most likely to impair penetration of egg investments?

  • Deficient mitochondrial DNA polymerase
  • Defective acrosomal hyaluronidase or acrosin
  • Lack of hexokinase
  • Absent cytochrome c oxidase

Correct Answer: Defective acrosomal hyaluronidase or acrosin

Q44. Which histological change is typical in testicular tissue after prolonged exposure to cytotoxic chemotherapy?

  • Hyperplasia of spermatogonia
  • Sertoli cell-only tubules and loss of germ cells
  • Increased Leydig cell function
  • Enhanced spermiation

Correct Answer: Sertoli cell-only tubules and loss of germ cells

Q45. Which parameter in semen analysis assesses sperm morphology?

  • Percentage of progressively motile sperm
  • Percentage of normal-appearing sperm forms
  • Semen pH
  • Viscosity measurement

Correct Answer: Percentage of normal-appearing sperm forms

Q46. Which genetic anomaly commonly causes impaired spermatogenesis and small testicular volume in males?

  • 46,XY normal karyotype
  • Klinefelter syndrome (47,XXY)
  • Turner syndrome (45,X)
  • Trisomy 21

Correct Answer: Klinefelter syndrome (47,XXY)

Q47. In assisted reproductive techniques, which sperm retrieval method is used for obstructive azoospermia?

  • Testicular sperm extraction (TESE)
  • Vasectomy
  • Peritoneal lavage
  • Transrectal ultrasound only

Correct Answer: Testicular sperm extraction (TESE)

Q48. Which seminal plasma component is produced by the seminal vesicles and helps nourish sperm?

  • Fructose
  • Prostate-specific antigen
  • Testosterone
  • Androgen-binding protein

Correct Answer: Fructose

Q49. Which clinical intervention can improve spermatogenesis in men with varicocele-associated infertility?

  • Antibiotics
  • Surgical varicocelectomy
  • Testosterone replacement therapy
  • High-dose vitamin E only

Correct Answer: Surgical varicocelectomy

Q50. Which cellular event marks the completion of meiosis in the male and yields functional haploid sperm nuclei?

  • Telophase of mitosis
  • Second meiotic division (meiosis II) resulting in spermatids
  • Spermiation before meiosis
  • Fusion with Sertoli cell cytoplasm

Correct Answer: Second meiotic division (meiosis II) resulting in spermatids

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