MCQs on Human Reproduction – Class 12 Biology NCERT
MCQs on Human Reproduction – Class 12 Biology (NCERT Based)
Course: CBSE Class 12 Biology | Unit I: Reproduction
MCQs with Answers and Elaborate Concept-Clearing Explanations
Section A: Introduction to Human Reproduction
Q1. Human reproduction is classified as
A. asexual reproduction
B. sexual reproduction
C. vegetative reproduction
D. parthenogenesis
Correct Answer: B
Explanation: Humans reproduce sexually, involving the formation and fusion of male and female gametes, resulting in genetic variation.
Q2. The primary purpose of human reproduction is to
A. ensure individual survival
B. increase body growth
C. maintain continuity of species
D. regulate metabolism
Correct Answer: C
Explanation: Reproduction ensures continuity of the human species by producing offspring.
Section B: Male Reproductive System
Q3. The primary sex organ in human males is the
A. penis
B. prostate gland
C. testis
D. vas deferens
Correct Answer: C
Explanation: Testes produce male gametes (sperms) and the hormone testosterone.
Q4. Spermatogenesis occurs in the
A. epididymis
B. seminiferous tubules
C. vas deferens
D. prostate gland
Correct Answer: B
Explanation: Seminiferous tubules inside testes are the site of sperm formation.
Q5. Leydig cells are responsible for secretion of
A. FSH
B. LH
C. testosterone
D. estrogen
Correct Answer: C
Explanation: Leydig (interstitial) cells secrete testosterone, essential for spermatogenesis and male secondary sexual characters.
Q6. Sertoli cells primarily function to
A. secrete testosterone
B. transport sperms
C. nourish developing sperms
D. store semen
Correct Answer: C
Explanation: Sertoli cells provide nourishment and support to developing spermatogenic cells.
Q7. The duct that carries sperms from epididymis to urethra is
A. ureter
B. vas deferens
C. ejaculatory duct
D. seminiferous tubule
Correct Answer: B
Explanation: Vas deferens transports sperms during ejaculation.
Q8. Seminal plasma is contributed mainly by
A. testes only
B. prostate gland and seminal vesicles
C. epididymis
D. scrotum
Correct Answer: B
Explanation: Seminal vesicles and prostate gland add secretions forming seminal plasma.
Section C: Female Reproductive System
Q9. The primary sex organ in human females is the
A. uterus
B. ovary
C. vagina
D. cervix
Correct Answer: B
Explanation: Ovaries produce ova and female sex hormones.
Q10. Oogenesis takes place in the
A. uterus
B. fallopian tube
C. ovary
D. cervix
Correct Answer: C
Explanation: Formation and maturation of ova occur in the ovaries.
Q11. The site of fertilisation in humans is the
A. uterus
B. cervix
C. vagina
D. ampulla of fallopian tube
Correct Answer: D
Explanation: Fertilisation usually occurs at the ampullary–isthmic junction of the fallopian tube.
Q12. The uterus is mainly meant for
A. ovum production
B. fertilisation
C. implantation and foetal development
D. hormone secretion
Correct Answer: C
Explanation: The uterus provides a site for implantation and growth of the embryo.
Q13. Which hormone is secreted by ovaries?
A. Testosterone
B. Thyroxine
C. Estrogen
D. Insulin
Correct Answer: C
Explanation: Ovaries secrete estrogen and progesterone.
Section D: Gametogenesis
Q14. Spermatogenesis begins at
A. birth
B. childhood
C. puberty
D. old age
Correct Answer: C
Explanation: Spermatogenesis starts at puberty due to increased secretion of gonadotropins.
Q15. One primary spermatocyte ultimately produces
A. one sperm
B. two sperms
C. three sperms
D. four sperms
Correct Answer: D
Explanation: Meiosis produces four haploid sperms from one primary spermatocyte.
Q16. In females, meiosis during oogenesis is completed
A. before birth
B. at puberty
C. only after fertilisation
D. during menstruation
Correct Answer: C
Explanation: Secondary oocyte completes meiosis II only after fertilisation.
Q17. Which structure is haploid?
A. Zygote
B. Primary oocyte
C. Secondary oocyte
D. Oogonium
Correct Answer: C
Explanation: Secondary oocyte is haploid.
Section E: Menstrual Cycle
Q18. Average duration of the menstrual cycle is
A. 21 days
B. 24 days
C. 28 days
D. 35 days
Correct Answer: C
Explanation: A normal menstrual cycle lasts about 28 days.
Q19. Ovulation generally occurs around
A. day 5
B. day 10
C. day 14
D. day 21
Correct Answer: C
Explanation: Ovulation usually occurs mid-cycle, around day 14.
Q20. Hormone responsible for ovulation is
A. FSH
B. LH
C. Estrogen
D. Progesterone
Correct Answer: B
Explanation: LH surge triggers ovulation.
Q21. Menstrual phase occurs due to
A. high estrogen
B. fertilisation
C. degeneration of corpus luteum
D. high progesterone
Correct Answer: C
Explanation: Degeneration of corpus luteum lowers progesterone, causing menstruation.
Q22. Absence of menstruation is called
A. ovulation
B. menopause
C. amenorrhea
D. menarche
Correct Answer: C
Explanation: Amenorrhea refers to absence of menstruation.
Section F: Fertilisation and Implantation
Q23. Fusion of sperm and ovum is known as
A. implantation
B. fertilisation
C. cleavage
D. gestation
Correct Answer: B
Explanation: Fertilisation forms the diploid zygote.
Q24. The immediate product of fertilisation is
A. embryo
B. foetus
C. zygote
D. blastocyst
Correct Answer: C
Explanation: Zygote is the first cell of the new individual.
Q25. Implantation occurs in the
A. ovary
B. oviduct
C. uterus
D. cervix
Correct Answer: C
Explanation: The blastocyst embeds in the uterine wall.
Q26. The hormone responsible for maintenance of pregnancy is
A. estrogen
B. LH
C. progesterone
D. oxytocin
Correct Answer: C
Explanation: Progesterone maintains uterine lining for pregnancy.
Section G: Pregnancy and Placenta
Q27. Human chorionic gonadotropin (hCG) is secreted by
A. pituitary
B. ovary
C. placenta
D. hypothalamus
Correct Answer: C
Explanation: Placenta secretes hCG, maintaining corpus luteum.
Q28. Placenta acts as
A. digestive organ
B. endocrine organ
C. respiratory organ
D. all of these
Correct Answer: D
Explanation: Placenta exchanges nutrients, gases and secretes hormones.
Q29. Average gestation period in humans is
A. 6 months
B. 7 months
C. 8 months
D. 9 months
Correct Answer: D
Explanation: Human gestation lasts about 9 months (280 days).
Q30. The fluid surrounding the foetus is
A. peritoneal fluid
B. amniotic fluid
C. cerebrospinal fluid
D. blood plasma
Correct Answer: B
Explanation: Amniotic fluid protects the foetus from shocks.
Section H: Parturition and Lactation
Q31. Childbirth is also known as
A. fertilisation
B. implantation
C. parturition
D. lactation
Correct Answer: C
Explanation: Parturition refers to the process of giving birth.
Q32. Hormone responsible for uterine contractions is
A. prolactin
B. oxytocin
C. estrogen
D. progesterone
Correct Answer: B
Explanation: Oxytocin stimulates strong uterine contractions.
Q33. Milk secretion after childbirth is called
A. gestation
B. fertilisation
C. lactation
D. ovulation
Correct Answer: C
Explanation: Lactation provides nutrition to the newborn.
Q34. Prolactin is responsible for
A. ovulation
B. milk production
C. uterine contraction
D. menstruation
Correct Answer: B
Explanation: Prolactin stimulates milk synthesis in mammary glands.
Section I: Conceptual & Application-Based MCQs
Q35. Which structure stores sperms temporarily?
A. Vas deferens
B. Epididymis
C. Testis
D. Urethra
Correct Answer: B
Explanation: Epididymis stores and matures sperms.
Q36. Which hormone initiates spermatogenesis?
A. Estrogen
B. Progesterone
C. FSH
D. Oxytocin
Correct Answer: C
Explanation: FSH stimulates Sertoli cells, initiating spermatogenesis.
Q37. The cervix opens into the
A. uterus
B. fallopian tube
C. vagina
D. ovary
Correct Answer: C
Explanation: Cervix connects uterus to vagina.
Q38. Which structure prevents polyspermy?
A. Zona pellucida
B. Amnion
C. Chorion
D. Placenta
Correct Answer: A
Explanation: Zona pellucida blocks entry of additional sperms.
Q39. Which event marks the beginning of pregnancy?
A. Ovulation
B. Fertilisation
C. Implantation
D. Menstruation
Correct Answer: C
Explanation: Pregnancy begins with successful implantation.
Q40. The foetus becomes fully developed at the end of
A. first trimester
B. second trimester
C. third trimester
D. implantation
Correct Answer: C
Explanation: Final development completes during the third trimester.
Section J: Higher-Order Thinking MCQs
Q41. Why is testosterone essential for males?
A. Ovulation
B. Spermatogenesis and secondary sexual characters
C. Milk production
D. Implantation
Correct Answer: B
Explanation: Testosterone regulates sperm formation and male traits.
Q42. Which hormone maintains corpus luteum in early pregnancy?
A. FSH
B. LH
C. hCG
D. Prolactin
Correct Answer: C
Explanation: hCG prevents degeneration of corpus luteum.
Q43. Which phase of menstrual cycle prepares uterus for implantation?
A. Menstrual phase
B. Follicular phase
C. Luteal phase
D. Ovulatory phase
Correct Answer: C
Explanation: Progesterone thickens endometrium in luteal phase.
Q44. Internal fertilisation in humans ensures
A. low survival rate
B. no variation
C. higher survival of zygote
D. no parental care
Correct Answer: C
Explanation: Internal fertilisation protects gametes and embryo.
Q45. Which hormone inhibits further ovulation during pregnancy?
A. Estrogen
B. Progesterone
C. FSH
D. Oxytocin
Correct Answer: B
Explanation: Progesterone suppresses ovulation during pregnancy.
Q46. Which structure forms placenta?
A. Endometrium only
B. Chorionic villi and uterine tissue
C. Amnion
D. Yolk sac
Correct Answer: B
Explanation: Placenta forms from foetal chorion and maternal tissue.
Q47. Why does menstruation stop during pregnancy?
A. High FSH
B. High estrogen and progesterone
C. Ovulation
D. Oxytocin
Correct Answer: B
Explanation: Hormonal levels maintain endometrium.
Q48. Which hormone initiates milk ejection?
A. Prolactin
B. Estrogen
C. Oxytocin
D. Progesterone
Correct Answer: C
Explanation: Oxytocin causes milk let-down.
Q49. Which event ensures diploid chromosome number in humans?
A. Meiosis
B. Spermatogenesis
C. Fertilisation
D. Menstruation
Correct Answer: C
Explanation: Fusion of haploid gametes restores diploidy.
Q50. The ultimate biological significance of human reproduction is
A. individual growth
B. population control
C. continuity of human species
D. hormonal balance
Correct Answer: C
Explanation: Reproduction ensures survival and continuity of humans.
✅ Strictly NCERT-aligned
✅ Ideal for CBSE Class 12 Board Exam preparation