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Microorganisms and Disease (8 Science)

Learn about microscopic life forms, bacteria, viruses, and their role in disease and fermentation. Understand how disease spreads and prevention methods.

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TL;DR: Learn about microscopic life forms, bacteria, viruses, and their role in disease and fermentation. Understand how disease spreads and prevention metho…

Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated Jul 23, 2026

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Learn about microscopic life forms, bacteria, viruses, and their role in disease and fermentation. Understand how disease spreads and prevention methods.

Microorganisms and Disease MCQs with Answers & Explanations

Q1. What are microorganisms?

  1. Visible to naked eye
  2. Organisms visible only under a microscope ✓ (correct)
  3. Large organisms
  4. Dead organisms

Q2. What are bacteria?

  1. Eukaryotic cells
  2. Prokaryotic cells without a nucleus ✓ (correct)
  3. Multicellular organisms
  4. Viruses

Q3. What are viruses made of?

  1. Only protein
  2. DNA and cell wall
  3. DNA or RNA surrounded by protein coat ✓ (correct)
  4. Cell membrane only

Q4. How do viruses reproduce?

  1. By binary fission
  2. By infecting host cells and using host machinery ✓ (correct)
  3. By photosynthesis
  4. Viruses do not reproduce

Q5. What are fungi?

  1. Prokaryotes
  2. Eukaryotic organisms that feed on dead organic matter ✓ (correct)
  3. Viruses
  4. Bacteria

Q6. How do infectious diseases spread?

  1. Through air only
  2. Through air, water, food, and direct contact ✓ (correct)
  3. Only through touch
  4. Only through water

Q7. What is immunization?

  1. Treatment of disease
  2. Prevention of disease through vaccines ✓ (correct)
  3. Complete cure
  4. Isolation of patients

Q8. What is fermentation?

  1. A harmful process
  2. Microbial breakdown of food producing useful products ✓ (correct)
  3. Viral replication
  4. Growth of mold

Q9. What is antibiotic resistance?

  1. Allergy to antibiotics
  2. Ability of bacteria to survive antibiotic drugs ✓ (correct)
  3. Weakness of immune system
  4. Viral infection

Q10. How can we prevent the spread of microorganisms?

  1. Ignore hygiene
  2. Practice good hygiene, vaccination, proper food storage ✓ (correct)
  3. Never wash hands
  4. Avoid all contact

Frequently Asked Questions

Are all microorganisms harmful?

No, many microorganisms are beneficial. Bacteria in soil help plants grow, in digestive system they aid digestion, in fermentation they create useful products, and some produce antibiotics.

What is the difference between bacteria and viruses?

Bacteria are living cells that can reproduce independently and grow in culture. Viruses are non-living and need host cells to reproduce. Antibiotics kill bacteria but not viruses.

More 8 Science MCQs

  • Light Reflection and Refraction
  • Electricity
  • Acids Bases and Salts
  • Life Processes
  • Carbon and its Compounds
  • Metals and Non-metals

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