Diseases, Causative Agents and Vaccines

Attempt the quiz above first, then review every question with its correct answer and a short explanation below.

1. Q1.Malaria is caused by a protozoan of the genus:

   • A.Leishmania
   • B.Trypanosoma
   • C.Entamoeba
   • D.Plasmodium✓ Correct Answer

   Explanation: Malaria is caused by Plasmodium species, such as P. vivax and P. falciparum.

2. Q2.Malaria is spread by the bite of the female:

   • A.Culex mosquito
   • B.Aedes mosquito
   • C.tsetse fly
   • D.Anopheles mosquito✓ Correct Answer

   Explanation: Only the female Anopheles mosquito carries the Plasmodium parasite.

3. Q3.Tuberculosis (TB) is caused by a:

   • A.virus
   • B.protozoan
   • C.bacterium✓ Correct Answer
   • D.fungus

   Explanation: TB is caused by the bacterium Mycobacterium tuberculosis, which mainly infects the lungs.

4. Q4.Poliomyelitis (polio) is caused by a:

   • A.virus✓ Correct Answer
   • B.bacterium
   • C.protozoan
   • D.fungus

   Explanation: Polio is caused by the poliovirus and can cause paralysis.

5. Q5.AIDS is caused by:

   • A.HPV
   • B.HBV
   • C.HIV✓ Correct Answer
   • D.H1N1

   Explanation: AIDS results from infection with the Human Immunodeficiency Virus (HIV), which attacks T helper cells.

6. Q6.Dengue fever is transmitted by the:

   • A.Anopheles mosquito
   • B.Culex mosquito
   • C.Aedes mosquito✓ Correct Answer
   • D.housefly

   Explanation: Dengue virus is spread by Aedes aegypti, which bites mainly during the day.

7. Q7.Cholera is caused by:

   • A.Vibrio cholerae✓ Correct Answer
   • B.Salmonella typhi
   • C.Clostridium tetani
   • D.Streptococcus pneumoniae

   Explanation: Cholera is a bacterial infection of the intestine spread through contaminated water and food.

8. Q8.The Widal test is used to diagnose:

   • A.malaria
   • B.typhoid✓ Correct Answer
   • C.tuberculosis
   • D.dengue

   Explanation: The Widal test detects antibodies against Salmonella typhi, the cause of typhoid.

9. Q9.Hepatitis B primarily affects which organ?

   • A.kidney
   • B.lungs
   • C.pancreas
   • D.liver✓ Correct Answer

   Explanation: Hepatitis B virus infects the liver and can cause chronic liver disease.

10. Q10.Rabies, spread by the bite of an infected animal, is caused by a virus that mainly attacks the:

    • A.liver
    • B.nervous system✓ Correct Answer
    • C.lungs
    • D.kidneys

    Explanation: The rabies virus travels along nerves to the brain, causing a nearly always fatal disease once symptoms start.

11. Q11.The first vaccine, against smallpox, was developed by:

    • A.Edward Jenner✓ Correct Answer
    • B.Louis Pasteur
    • C.Robert Koch
    • D.Alexander Fleming

    Explanation: Edward Jenner used cowpox material to protect against smallpox in 1796.

12. Q12.The BCG vaccine gives protection against:

    • A.polio
    • B.typhoid
    • C.measles
    • D.tuberculosis✓ Correct Answer

    Explanation: BCG stands for Bacillus Calmette-Guérin and protects against TB.

13. Q13.The tuberculosis bacillus was discovered in 1882 by:

    • A.Louis Pasteur
    • B.Edward Jenner
    • C.Robert Koch✓ Correct Answer
    • D.Joseph Lister

    Explanation: Robert Koch identified the TB bacillus and was awarded the 1905 Nobel Prize for his TB work.

14. Q14.In 1980 the WHO declared which human disease eradicated worldwide?

    • A.polio
    • B.malaria
    • C.measles
    • D.smallpox✓ Correct Answer

    Explanation: Smallpox was declared eradicated in 1980 after a global vaccination campaign.

15. Q15.Which of the following is a genetic, non-infectious disorder?

    • A.haemophilia✓ Correct Answer
    • B.cholera
    • C.malaria
    • D.typhoid

    Explanation: Haemophilia is a sex-linked recessive disorder of blood clotting. The others are infections.

16. Q16.Penicillin, the first antibiotic, was discovered in 1928 by:

    • A.Louis Pasteur
    • B.Alexander Fleming✓ Correct Answer
    • C.Edward Jenner
    • D.Joseph Lister

    Explanation: Fleming noticed the mould Penicillium killing bacteria in a culture plate.

17. Q17.Kala-azar (visceral leishmaniasis) is transmitted by the:

    • A.tsetse fly
    • B.sandfly✓ Correct Answer
    • C.Culex mosquito
    • D.housefly

    Explanation: Leishmania donovani is carried by the female sandfly.

18. Q18.African sleeping sickness is caused by a protozoan of the genus:

    • A.Plasmodium
    • B.Trypanosoma✓ Correct Answer
    • C.Entamoeba
    • D.Giardia

    Explanation: Trypanosoma brucei is transmitted by the tsetse fly.

19. Q19.Filariasis (elephantiasis) is caused by:

    • A.a protozoan
    • B.a virus
    • C.a nematode worm, Wuchereria bancrofti✓ Correct Answer
    • D.a fungus

    Explanation: The parasitic worm Wuchereria bancrofti blocks lymph vessels and is spread by the Culex mosquito.

20. Q20.Bovine spongiform encephalopathy (mad cow disease) is caused by:

    • A.prions✓ Correct Answer
    • B.viroids
    • C.bacteria
    • D.protozoa

    Explanation: Prions are misfolded infectious proteins with no nucleic acid.