Biology · Textbook solutions

Microbes in Human Welfare

Every solved example, exercise, and miscellaneous question, in the order the textbook teaches them. · 16 questions

Exercises

16 q

Ex 8 Q1 $Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes with the help of a microscope, which sample would you carry and why?$
Ex 8 Q2 $Give examples to prove that microbes release gases during metabolism.$
Ex 8 Q3 $In which food would you find lactic acid bacteria? Mention some of their useful applications.$
Ex 8 Q4 $Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.$
Ex 8 Q5 $In which way have microbes played a major role in controlling diseases caused by harmful bacteria?$
Ex 8 Q6 $Name any two species of fungus, which are used in the production of the antibiotics.$
Ex 8 Q7 $What is sewage? In which way can sewage be harmful to us?$
Ex 8 Q8 $What is the key difference between primary and secondary sewage treatment?$
Ex 8 Q9 $Do you think microbes can also be used as source of energy? If yes, how?$
Ex 8 Q10 $Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.$
Ex 8 Q11 $Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?$
Ex 8 Q12 $Find out the name of the microbes from which Cyclosporin A (an immunosuppressive drug) and Statins (blood cholesterol lowering agents) are obtained.$
Find out the role of microbes in the following and discuss it with your teacher.
Ex 8 Q13 (a) $Single cell protein (SCP)$
Ex 8 Q13 (b) $Soil$
Ex 8 Q14 $Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer. Biogas, Citric acid, Penicillin and Curd$
Ex 8 Q15 $How do biofertilisers enrich the fertility of the soil?$