Exercises

1. Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes with the help of a microscope, which sample would you carry and why?

2. Give examples to prove that microbes release gases during metabolism.

3. In which food would you find lactic acid bacteria? Mention some of their useful applications.

4. Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.

5. In which way have microbes played a major role in controlling diseases caused by harmful bacteria?

6. Name any two species of fungus, which are used in the production of the antibiotics.

7. What is sewage? In which way can sewage be harmful to us?

8. What is the key difference between primary and secondary sewage treatment?

9. Do you think microbes can also be used as source of energy? If yes, how?

10. Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.

11. BOD test results: A (20mg/L), B (8mg/L), C (400mg/L). Which sample is most polluted? Assign correct labels.

12. Find the names of microbes for:

13. Role of microbes in:

14. Arrange in decreasing order of importance: Biogas, Citric acid, Penicillin, Curd.

15. How do biofertilisers enrich the fertility of the soil?