Page 3 - Assignment-Microbes in Human Welfare

13. What is biochemical oxygen demand (BOD) test? At what stage of Sewage treatment
this test is performed?
BOD level of three samples of water labelled as A, B and C are 30 mg/L, 10mg/L
and 500 mg/L respectively. Which sample of water is most polluted?
14. Given below is the Flow chart of Sewage treatment. Fill in the blank spaces marked
‘a’ to ‘f’.

15. What are biofertilisers? A farmer is advised to add a culture of bacterium in the soil
before sowing the crop. Name the bacterium in the culture. How is this bacterium
useful to the crop?
16. What are Statins? Name the microorganism that produces this substance. How is it
medically important?

E. Long Answer Questions (5 marks each)