Class 9 Practice Level 3 – Why do we fall ill set – 1 Leave a Comment / By anushka kumari / July 12, 2024 Class 9 Practice Level 3 – Why do we fall ill set - 1 Total questions: 29 1. Which feature of viruses makes them unique compared to other pathogens like bacteria and fungi? They have cell walls. They can reproduce independently. They require a host cell to replicate. They perform photosynthesis. None 2. Which cells are primarily responsible for the adaptive immune response? Red blood cells Platelets B and T lymphocytes Neutrophils None 3. How does horizontal gene transfer contribute to antibiotic resistance in bacteria? By killing non-resistant bacteria By mutation during cell division By transferring resistance genes between bacteria By increasing the metabolism of bacteria None 4. Why is herd immunity important in the context of highly contagious diseases like measles? It allows the disease to spread more easily. It protects those who are not immune. It reduces the need for vaccination. It increases the mutation rate of the virus. None 5. What is the primary difference between chronic and acute diseases? Chronic diseases are always fatal, while acute diseases are not. Acute diseases develop slowly, while chronic diseases develop rapidly. Chronic diseases last for a long time, while acute diseases have a rapid onset and short duration. Acute diseases are non-communicable, while chronic diseases are communicable. None 6. Which of the following strategies is most effective in controlling the spread of vector-borne diseases? Increasing vaccination rates Promoting handwashing Using insecticides and eliminating breeding sites Ensuring clean drinking water None 7. How do memory cells function in the immune system? They produce antibodies during the first exposure to a pathogen. They retain information about past infections and respond quickly upon re-exposure. They act as the first line of defence against all pathogens. They engulf and digest pathogens directly. None 8. What is the underlying cause of autoimmune diseases? Infection by a specific pathogen Deficiency of vitamins Immune system attacking the body's own cells Lack of exercise None 9. How does a deficiency in vitamin A affect the body? It causes scurvy. It leads to rickets. It impairs vision and immune function. It results in anaemia. None 10. How do airborne diseases primarily spread? Through direct contact with skin Through contaminated food and water Through droplets in the air from coughing or sneezing Through insect bites None 11. What role do adjuvants play in vaccines? They kill the pathogen. They suppress the immune response. They enhance the body's immune response to the vaccine. They cause allergic reactions. None 12. Why is it important to identify the index case in an outbreak? To blame the individual for spreading the disease To understand the origin and track the spread of the disease To increase the spread of the disease To promote panic among the population None 13. How does chronic inflammation contribute to disease development? By preventing infections By damaging tissues and organs over time By boosting the immune response By improving overall health None 14. Which of the following measures is most effective in controlling a disease outbreak? Ignoring the symptoms Delaying medical intervention Quarantine and isolation of infected individuals Promoting close contact among people None 15. Which immune system disorder is characterized by the body's inability to produce enough insulin? Rheumatoid arthritis Type 1 diabetes Lupus Multiple sclerosis None 1 out of 15 Time's up