MDCAT Biology chapter 8: Biology · Reproduction MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
31 exam-style questions on Biology · Reproduction, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. The umbilical cord joins the foetus to the placenta. Which statement about the blood vessels in the cord is correct?
A
two veins carry deoxygenated blood to the placenta; one artery carries oxygenated blood to the foetus
B
two arteries carry oxygenated blood to the foetus; one vein carries deoxygenated blood to the placenta
C
two arteries carry deoxygenated blood to the placenta; one vein carries oxygenated blood to the foetus
D
one artery and one vein carry the mother's blood into and out of the foetus
Show answer
Answer: C. The foetal heart pumps deoxygenated blood to the placenta along the two umbilical arteries, and the single umbilical vein brings back blood that has been oxygenated in the placenta. Names follow the direction relative to the heart, not the oxygen content, and maternal and foetal blood do not mix.
2. In humans, 50 primary spermatocytes and 50 primary oocytes each complete meiosis normally. How many sperm and ova are formed?
A
200 sperm and 200 ova
B
200 sperm and 50 ova
C
100 sperm and 50 ova
D
50 sperm and 50 ova
Show answer
Answer: B. Each primary spermatocyte gives four sperm (50 × 4 = 200), but each primary oocyte gives only one ovum, the other products being polar bodies (50 × 1 = 50). 100 sperm wrongly counts two cells per meiosis.
3. In human spermatogenesis, which are the last diploid cells before meiosis halves the chromosome number?
A
secondary spermatocytes
B
spermatids
C
primary spermatocytes
D
spermatozoa
Show answer
Answer: C. Spermatogonia divide by mitosis and grow into primary spermatocytes (2n). Meiosis I then gives haploid secondary spermatocytes, meiosis II gives spermatids, and these mature into sperm.
4. Ovulation in the human menstrual cycle is triggered by a sudden surge in the secretion of
A
progesterone
B
LH
C
prolactin
D
oxytocin
Show answer
Answer: B. A sharp rise (surge) of luteinising hormone from the anterior pituitary, around the middle of the cycle, makes the mature Graafian follicle burst and release the secondary oocyte.
5. Which statement about the human placenta is correct?
A
maternal and foetal blood do not normally mix
B
maternal blood is pumped directly through the foetal heart
C
it is formed entirely from tissues of the mother
D
it lets all maternal blood cells pass to the foetus
Show answer
Answer: A. Oxygen, nutrients and wastes are exchanged across thin membranes between the foetal capillaries and the maternal blood spaces, but the two bloods do not mix. The placenta is formed partly from foetal tissue (chorion) and partly from the endometrium.
6. Identical (monozygotic) twins develop when
A
one oocyte is fertilised by two sperm at the same time
B
two secondary oocytes are fertilised by two different sperm
C
the blastomeres of one early embryo separate and each forms an embryo
D
one sperm fertilises the oocyte and another fertilises its polar body
Show answer
Answer: C. If the cells (blastomeres) of a single zygote separate during cleavage, each group can develop into a complete embryo; the twins have the same genes and so the same sex. Two oocytes fertilised by two sperm give fraternal (non-identical) twins.
7. A 22-year-old woman who is not pregnant stops having menstrual periods for several months during a time of severe emotional stress and poor diet. The most likely explanation is that
A
she has reached her menopause many years early
B
stress and poor nutrition have upset her hormone balance
C
her pituitary is releasing extra FSH and LH
D
her endometrium no longer responds to any hormones
Show answer
Answer: B. Emotional stress and malnutrition can disturb the hypothalamus and pituitary, so the FSH and LH needed for follicle growth and ovulation are not released normally and periods stop; they usually return when health improves. The menopause, when the ovaries run out of follicles, normally comes much later in life.
8. Oogenesis produces small polar bodies because
A
polar bodies are spare ova kept in case the first is lost
B
polar bodies release enzymes that attract sperm to the ovum
C
polar bodies supply food to the embryo after implantation
D
unequal division gives one ovum most of the cytoplasm
Show answer
Answer: D. At both meiotic divisions the chromosomes are shared equally but the cytoplasm is not: almost all the cytoplasm and stored food go to one cell, the future ovum. The tiny polar bodies degenerate.
9. The inner lining of the uterus, which thickens during each cycle and is shed at menstruation, is the
A
endometrium
B
myometrium
C
cervix
D
corpus luteum
Show answer
Answer: A. The endometrium is the glandular, blood-rich inner lining of the uterus. The myometrium is the thick muscular wall of the uterus, which contracts during birth.
10. In a vasectomy, both vasa deferentia are cut and tied. Afterwards the man's semen contains no sperm, but his male secondary sexual characteristics are unchanged. This is because
A
testosterone is made by the seminal vesicles, not the testes
B
these characters are controlled by FSH alone, not by testosterone
C
sperm stored in the epididymis go on releasing hormones
D
the testes still secrete testosterone into the blood
Show answer
Answer: D. Testosterone is a hormone: the interstitial cells secrete it directly into the blood, not into the sperm ducts, so cutting the vasa deferentia blocks sperm but not the hormone. Secondary sexual characteristics depend on testosterone, not on FSH.
31, each with the answer and a short explanation, across 2 topics: Human reproductive systems, Reproductive cycle and development. Every chapter test draws ten of them, so you can take it many times.
Is the MDCAT Biology chapter 8 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
