Free Human Reproductive System MCQs with Answers

31. The average length of a complete menstrual cycle in human females is about

• A. 14 days
• B. 21 days
• C. 28 days
• D. 35 days

Explanation: Counting from the first day of one menstruation to the day before the next gives roughly 28 days, though normal cycles vary between about 21 and 35. Fourteen days is only the average time from menstruation to ovulation.

32. The causative agent of syphilis is

• A. a virus
• B. a fungus
• C. a protozoan
• D. the bacterium Treponema pallidum

Explanation: Treponema pallidum is a spirochaete bacterium, which is why syphilis responds to penicillin. Viral STDs such as HIV and herpes cannot be cured with antibiotics, an important clinical distinction.

33. Genital warts are caused by the

• A. human papillomavirus
• B. human immunodeficiency virus
• C. herpes simplex virus
• D. bacterium Neisseria gonorrhoeae

Explanation: Certain strains of HPV produce warts, and other high risk strains can transform cervical cells. Being viral, warts cannot be treated with antibiotics, which is why vaccination against HPV is the best protection.

34. The HPV vaccine offered to adolescent girls protects mainly against

• A. gonorrhoea
• B. cervical cancer
• C. syphilis
• D. hepatitis A

Explanation: By immunising against the cancer causing strains of human papillomavirus, the vaccine prevents most cases of cervical cancer decades later. It does not protect against bacterial STDs such as gonorrhoea and syphilis.

35. The bacterial STD that frequently causes no symptoms, especially in women, yet can silently lead to infertility is

• A. syphilis
• B. gonorrhoea
• C. chlamydia
• D. genital herpes

Explanation: Chlamydia is the commonest bacterial STD and often passes unnoticed until it damages the oviducts, causing pelvic inflammatory disease and infertility. Its quiet course is why screening programmes target young people.

36. Which of the following sexually transmitted diseases is caused by a protozoan?

• A. Gonorrhoea
• B. Syphilis
• C. AIDS
• D. Trichomoniasis

Explanation: Trichomonas vaginalis is a flagellated protozoan causing discharge and irritation, and it is treated with antiprotozoal drugs. Gonorrhoea and syphilis are bacterial and AIDS is viral, so only trichomoniasis fits the protozoan description.

37. Untreated gonorrhoea in women may spread upwards and cause

• A. kidney stones
• B. diabetes mellitus
• C. anaemia
• D. pelvic inflammatory disease and infertility

Explanation: The gonococcus can climb from the cervix into the uterus and oviducts, inflaming and scarring them, which blocks the passage of eggs. Early antibiotic treatment prevents this chain, which is why prompt diagnosis matters.

38. Which of the following infections can be transmitted sexually but is preventable by vaccination?

• A. Hepatitis B
• B. Gonorrhoea
• C. Syphilis
• D. HIV

Explanation: Hepatitis B virus spreads in blood and sexual fluids and can damage the liver, but a highly effective recombinant vaccine exists. No vaccine yet protects against HIV, gonorrhoea or syphilis.

39. When one partner is diagnosed with a curable bacterial STD, treatment should be given to

• A. only the partner showing symptoms
• B. both partners, to prevent reinfection
• C. only the male partner
• D. only the female partner

Explanation: An untreated partner harbours the organism and passes it straight back, so both must be treated even if one feels well. This partner notification principle applies to gonorrhoea, syphilis and chlamydia alike.

40. The painless sore called a chancre appears in which stage of syphilis?

• A. Secondary stage
• B. Tertiary stage
• C. Primary stage
• D. Congenital stage

Explanation: About three weeks after infection a chancre forms at the entry point, marking primary syphilis, and heals on its own, which lets the disease go unnoticed. The rash belongs to the secondary stage and gummas to the tertiary.