CHAPTER- 8: MICROBES IN HUMAN WELFARE
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?
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2. Give examples to prove that microbes release gases during metabolism.
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3. In which food would you find lactic acid bacteria? Mention some of their useful applications.
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4. Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.
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5. In which way have microbes played a major role in controlling diseases caused by harmful bacteria?
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6. Name any two species of fungus, which are used in the production of the antibiotics.
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7. What is sewage? In which way can sewage be harmful to us?
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8. What is the key difference between primary and secondary sewage
treatment?
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9. Do you think microbes can also be used as source of energy? If yes, how?
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10. Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.
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11. Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?
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DABP006912
