Free Reproduction MCQs with Answers

21. The female gonads that produce ova and secrete the hormones oestrogen and progesterone are the

• A. ovaries
• B. uterus
• C. oviducts
• D. vagina

Explanation: The ovaries are both the source of egg cells and an endocrine gland, releasing the hormones that control the menstrual cycle and pregnancy. The uterus receives the embryo and the oviduct is the site of fertilisation, but neither produces gametes.

22. The inner lining of the uterus, which thickens each cycle and is shed during menstruation, is the

• A. perimetrium
• B. endometrium
• C. myometrium
• D. cervix

Explanation: The endometrium is the hormonally responsive layer where the embryo implants. The myometrium is the muscular wall that contracts in labour and the perimetrium the outer covering, so only the endometrium is shed in menstruation.

23. After their production, spermatozoa mature and are temporarily stored in the

• A. seminal vesicles
• B. prostate gland
• C. epididymis
• D. urethra

Explanation: Sperm leaving the seminiferous tubules are not yet motile; they gain the ability to swim while passing through the coiled epididymis where they are stored. The seminal vesicles and prostate only add fluid at the moment of ejaculation.

24. The secretion of the seminal vesicles is rich in a sugar that serves as fuel for sperm. This sugar is

• A. glucose
• B. sucrose
• C. lactose
• D. fructose

Explanation: Fructose provides the energy that powers the tail of the sperm during its journey. The prostate contributes a milky alkaline fluid instead, protecting sperm from the acidity of the vagina.

25. The testes hang in the scrotum outside the body cavity because

• A. sperm production needs a temperature slightly below body temperature
• B. the testes are too large to fit inside the abdomen
• C. testosterone breaks down at body temperature
• D. sperm must be released directly to the outside

Explanation: Spermatogenesis fails at the normal 37 degrees of the abdomen, so the scrotum keeps the testes about two degrees cooler. This is why undescended testes in childhood need correction to preserve fertility.

26. The umbilical cord of a human fetus normally contains

• A. one artery and one vein
• B. two arteries and one vein
• C. two arteries and two veins
• D. one artery and two veins

Explanation: Two umbilical arteries carry deoxygenated blood and wastes from fetus to placenta, while the single umbilical vein returns oxygenated blood and nutrients. Veins here carry waste and arteries carry it away, the reverse of the adult pattern, which catches many students.

27. After fertilisation, the zygote undergoes a series of rapid mitotic divisions without overall growth, called

• A. meiosis
• B. gastrulation
• C. cleavage
• D. implantation

Explanation: Cleavage divides the zygote into a ball of smaller cells as it travels down the oviduct, forming the morula and then the blastocyst. Meiosis makes gametes, and implantation happens later, once the blastocyst reaches the uterus.

28. Which of the following is NOT a part of the male reproductive system?

• A. Prostate gland
• B. Vas deferens
• C. Seminal vesicle
• D. Uterus

Explanation: The uterus belongs to the female system, where it nourishes the developing fetus. The prostate and seminal vesicles add fluids to semen, and the vas deferens transports sperm, so all three are male structures.

29. The changes of puberty in boys, such as a deeper voice and facial hair, are driven mainly by

• A. testosterone
• B. oestrogen
• C. progesterone
• D. insulin

Explanation: Testosterone from the Leydig cells stimulates the development of male secondary sexual characteristics and continues to support sperm production. Oestrogen and progesterone are the principal female sex hormones, though small amounts occur in both sexes.

30. The narrow lower end of the uterus that opens into the vagina is called the

• A. oviduct
• B. cervix
• C. ovary
• D. urethra

Explanation: The cervix produces mucus that changes through the cycle, guides sperm and protects the uterus during pregnancy. The urethra is part of the urinary system, a common confusion since both open near each other in the female.