Try each question on your own first. Use the Show Answer button only after you have selected your option, then read the explanation and revise the related concept from your chapter notes.
1. Which of the following is defined as a state of complete physical, mental, and social well-being?
A. Fitness
B. Health
C. Immunity
D. Disease-free state
Answer: B. Health
Explanation: According to the WHO, health is a state of complete physical, mental, and social well-being, and not merely the absence of disease.
2. Which of the following diseases is classified as a chronic disease?
A. Common Cold
B. Tuberculosis (TB)
C. Influenza
D. Cholera
Answer: B. Tuberculosis (TB)
Explanation: Chronic diseases last for a long time or even a lifetime. TB and Elephantiasis are examples, whereas common cold is an acute disease.
3. Which of the following diseases is transmitted by a protozoan pathogen?
A. Malaria
B. Typhoid
C. Tuberculosis
D. Polio
Answer: A. Malaria
Explanation: Malaria is caused by the protozoan *Plasmodium*, transmitted through the bite of an infected female *Anopheles* mosquito.
4. Which organism causes Kala-azar (visceral leishmaniasis)?
A. Trypanosoma
B. Leishmania
C. Ascaris
D. Staphylococci
Answer: B. Leishmania
Explanation: *Leishmania* is a protozoan parasite that causes Kala-azar (transmitted by sandflies).
5. Penicillin is an antibiotic that blocks the chemical pathway for making cell walls in:
A. Viruses
B. Bacteria
C. Fungi
D. Protozoans
Answer: B. Bacteria
Explanation: Penicillin blocks bacterial cell-wall synthesis. It does not work on viruses, as viruses do not use cell walls or bacterial metabolic pathways.
6. Which vector transmits Dengue and Yellow Fever viruses?
A. Female Anopheles Mosquito
B. Aedes Mosquito
C. Culex Mosquito
D. Housefly
Answer: B. Aedes Mosquito
Explanation: The *Aedes aegypti* mosquito acts as a vector for viral diseases such as Dengue, Chikungunya, and Yellow Fever.
7. AIDS (Acquired Immunodeficiency Syndrome) is caused by which pathogen?
A. Bacterium
B. Protozoan
C. HIV (Virus)
D. Fungus
Answer: C. HIV (Virus)
Explanation: AIDS is caused by the Human Immunodeficiency Virus (HIV), which damages the host immune system.
8. Immunization or vaccination works on the principle of:
A. Blocking bacterial cell wall formation
B. Memory function of the immune system
C. Increasing body mass
D. Reducing body temperature
Answer: B. Memory function of the immune system
Explanation: Vaccines introduce dead or weakened microbes, training the immune system to recognize and produce specific antibodies for faster response upon future exposures.
9. Which of the following is an airborne disease?
A. Cholera
B. Typhoid
C. Pneumonia
D. Hepatitis
Answer: C. Pneumonia
Explanation: Pneumonia, Common Cold, and Tuberculosis spread through droplets released into the air when an infected person coughs or sneezes.
10. What type of disease affects the liver and causes yellowing of the skin and eyes (jaundice)?
A. Rabies
B. Hepatitis
C. Malaria
D. Tetanus
Answer: B. Hepatitis
Explanation: Hepatitis is inflammation of the liver caused by viral infection (e.g., Hepatitis A/B) often transmitted via contaminated water or body fluids.
This page contains a chapter-wise objective practice set. Try the questions without checking the answer first, then use the explanation to understand the point you missed. The current page contains 10 questions, so you can practise in smaller sets when you are revising.
Quick revision tip
After the practice set, write down the question numbers you missed and revise only those concepts once more. This makes MCQ practice more useful than repeatedly attempting the same questions without reviewing mistakes.
