Extra Questions: Class 8 Science Chapter 3 Health The Ultimate Treasure

Practice questions beyond the textbook exercise, testing deeper understanding of health, disease and immunity for Class 8 Science Chapter 3: Health: The Ultimate Treasure. These Class 8 Science Chapter 3 important questions are handy for last-minute exam practice.

Extra Questions: Class 8 Science Chapter 3 Health The Ultimate Treasure

1. 1 (Assertion-Reason). Assertion: Vaccines prevent disease without causing the illness itself. Reason: Vaccines train the immune system using a weakened, dead, or partial form of the pathogen.
   Solution: Both true, and the reason correctly explains the assertion.
2. 2 (Short Answer). Name two diseases spread by mosquitoes.
   Solution: Malaria and Dengue (Chikungunya is also acceptable).
3. 3 (Applied). A student takes antibiotics every time they get a cold. Explain why this is a harmful habit.
   Solution: Colds are viral, so antibiotics have no effect on them; repeated unnecessary use promotes antibiotic resistance, making bacteria harder to treat in future genuine bacterial infections.
4. 4 (Assertion-Reason). Assertion: Handwashing reduces the spread of communicable diseases. Reason: Many pathogens spread through contact with contaminated hands and surfaces.
   Solution: Both true, and the reason correctly explains the assertion.
5. 5 (Synthesis). Explain, using the idea of memory cells, why chickenpox usually only infects a person once in their lifetime.
   Solution: After the first infection, the immune system retains memory B- and T-cells specific to the chickenpox virus; on future exposure these cells respond immediately and strongly, clearing the virus before it can cause illness again.
6. 6 (Short Answer). Give one example each of a water-borne and an airborne communicable disease.
   Solution: Water-borne: Cholera (or Typhoid/Hepatitis A). Airborne: Tuberculosis (or Flu/Measles).
7. 7 (Applied). A locality has poor sanitation and frequent waterlogging. Predict two communicable diseases likely to rise there, and explain why.
   Solution: Cholera/Typhoid (contaminated water from poor sanitation) and Dengue/Malaria (waterlogging creates mosquito breeding grounds).
8. 8 (Assertion-Reason). Assertion: Stress can make a person more likely to fall sick. Reason: Chronic stress suppresses immune function.
   Solution: Both true, and the reason correctly explains the assertion.
9. 9 (Short Answer). What is the WHO definition of health?
   Solution: A state of complete physical, mental and social well-being — not merely the absence of disease.
10. 10 (Applied). Why do doctors recommend completing the full course of antibiotics even after symptoms disappear?
    Solution: Stopping early can leave some bacteria alive, which may develop resistance to the antibiotic, making the infection harder to treat if it recurs.

Written by Satish

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