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

Primary treatment of wastes involves the  physical removal of particles. It involves methods like sedimentation and fitration. It is comparitively less expensive

Secondary treatment of waste involves the biological removal of dissolved organic matter. It involves the use of microbes. It is an expensive process.

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Find out the name of the microbes from which Cyclosporin A (an immunosuppressive drug) and Statins (blood cholesterol lowering agents) are obtained.
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 under a microscope, which sample would you carry and why ?
Give examples to prove that microbes release gases during metabolism.

Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.
In which way microbes have played a major role in controlling diseases caused by harmful bacteria ?

 
Name any two species of fungus, which are used in the production of antibiotics.
What is sewage ? In which way can this be harmful ?
Do you think microbes can be used as source of energy ? If yes, how ?
Microbes can be used to lessen the burden of use of chemical pesticides. Explain how this can be accomplished.
Find out the role of microbes in the following and discuss it with your teacher.

(a) Single cell protein (SCP) (b) Soil.
In which food would you find lactic acid bacteria ? Mention some of their useful applications.
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 20 mg / L, 8 mg / L, and 400 mg / 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 ?
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.
How do biofertilizers enrich the soil ?

A good producer of citric acid is

Match the following list of microbes and their importance:

(a) Sacharomyces cerevisiae (i) Production of immunosuppressive agents
(b) Monascus purpureus (ii) Riperuing of Swiss cheese
(c) Trichoderma polysporum (iii) Commercial production of ethanol
(d) Propionibacterium sharmanii (iv) Production of blood cholesterol lowering agents

Monascus purpureus is a yeast used commercially in the production of 

A patient brought to a hospital with myocardial infarction is normally immediately given

Which one of the following is not a property of cancerous cells, whereas the remaining three are?

The initial step in the digestion of milk in humans is carried out by?