Class 8 Science – Chapter 2
Microorganisms: Friend and Foe
MCQs (Exam Level)

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1. Which of the following is a microorganism?
   A. Ant
   B. Bacteria
   C. Earthworm
   D. Frog

   Answer: B. Bacteria

2. Which microorganism is used in the preparation of curd?
   A. Yeast
   B. Virus
   C. Lactobacillus
   D. Algae

   Answer: C. Lactobacillus

3. Malaria is caused by:
   A. Virus
   B. Bacteria
   C. Protozoa
   D. Fungi

   Answer: C. Protozoa

4. Which disease is caused by a virus?
   A. Cholera
   B. Tuberculosis
   C. Polio
   D. Typhoid

   Answer: C. Polio

5. Antibiotics are used to treat:
   A. Viral diseases
   B. Bacterial diseases
   C. Fungal diseases
   D. All diseases

   Answer: B. Bacterial diseases

6. Which of the following helps in nitrogen fixation?
   A. Virus
   B. Algae
   C. Rhizobium
   D. Amoeba

   Answer: C. Rhizobium

7. Pasteurization is mainly done to:
   A. Increase taste
   B. Preserve food
   C. Kill harmful germs
   D. Add nutrients

   Answer: C. Kill harmful germs

8. Which microorganism causes bread to rise?
   A. Bacteria
   B. Virus
   C. Yeast
   D. Protozoa

   Answer: C. Yeast

9. Food poisoning is mainly caused due to:
   A. Useful bacteria
   B. Harmful microorganisms
   C. Vitamins
   D. Minerals

   Answer: B. Harmful microorganisms

10. Which one is NOT a method of food preservation?
    A. Salting
    B. Refrigeration
    C. Boiling
    D. Vaccination

    Answer: D. Vaccination

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