Microbes in Human Welfare Test - 11

The organisms that can grow at higher temperature are called hyperthermophilic organisms. These organisms belong to group Eubacteria and Archaea.

Rennet is complex enzyme produced in stomachs of ruminant mammals which is used in the production of most cheeses. It is also available in market in forms of liquid and tablets.

Tissue plasminogen activator is a protein involved in the breakdown of blood clots. It is a serine protease, an enzyme found on endothelial cells. This enzyme catalyse the clot breakdown.

Bioreactor is a fermentation tank in which fermentation is carried out regularly. This tank is fitted with instruments that control the optimal temperature and pressure required for fermentation.

Depending upon the type of the raw material used for fermentation and type of processing different types of alcoholic drinks are obtained. Wine and Beer are produced without distillation.

Monascus purpureus is Yeast used commercially in the production of blood cholesterol lowering statins. Blood cholesterol is responsible for a number of heart disease.

Cyclosporin A is used as an immunosuppressive agent in organ-transplant patient obtained from Trichoderma polysporum fungus.

Enzyme immobilization is the process whereby the movement of enzymes cells organelles etc. in space is completely or severely restricted usually resulting in a water soluble enzyme thus providing enzyme with protective covering.

Dough used for making food such as dosa and idli is fermented by bacterial. The puffed-up appearance of dough is due to the production of carbon dioxide gas.

Methanogens is present in cow dung that produces methane gas. It is most common in cattle yard that provide unique smell in surrounding areas.

Primary treatment of sewage treatment involves physical removal of large and small particles like paper, plastic, pebble by passing through screen.

During anaerobic decomposition of organic wastes by bacteria biogas is produced but lignin do not get decomposed by these bacteria and left over in biogas plants.

The technology of biogas production was developed in India mainly due to the efforts of IARI (Indian Agricultural Research Institute) and KVIC (Khadi and Village Industries Commission).

During secondary treatment a small part of activated sludge is pumped back into aeration tank to serve as the inoculum. The remaining part of the sludge is pumped into large tanks called aerobic sludge digester.

Correct Answer : b

Explanation : Sewage mainly includes human excreta and contains large amounts of organic waste and pathogenic microbes. Thus it is necessary that waste should be made less polluted before discharging into water bodies. 

The process of sewage treatment is explained in the following steps:

a) Primary treatment- In this treatment, filtration and sedimentation process is applied to remove large and small particles. Filtration process removes the floating debris by passing it through mesh wire screens. Then sedimentation removes the soil and small pebbles. The sediment is known as primary sludge and the supernatant is known as primary effluent. The effluent then enters the secondary treatment. 

b) Secondary treatment- In this treatment, large aeration tanks containing primary effluent are constantly agitated with a continuous supply of air. Thus aerobic microbes grow vigorously consuming a major part of the organic effluent reducing Biological Oxygen Demand (BOD) of the effluent. The sewage is then passed into the settling tank where bacteria settle and now it is known as activated sludge. Some of the activated sludge is again passed into aeration tank to serve as inoculum while rest of it enters into large tanks called anaerobic sludge digesters. Here anaerobic bacteria grow to produce a mixture of gases such as methane, hydrogen sulphide and carbon dioxide to form biogas. This effluent can then be released into natural water bodies.

Rotenone is a naturally occurring chemical with insecticidal properties, obtained from the roots of the several tropical and subtropical plant species.

Symbiotic association of fungi with angiosperm plant root is called mycorrhiza. Most of the plants have this kind of relation. The fungus obtains some sugar from the plant and plant get minerals and water absorbed by fungi.

Organic farming is the practice of agriculture in which on chemical substance is used as fertilizers, pesticides or insecticides. Biofertilizers are used to provide nutrient.

In organic farming snail is not used. Glomus is kind of fungi used in organic farming for maintaining fertility of soil. Earthworm the process of composting to form vermiform compost and Oscillatoria is an algae that fix the nitrogen.

Tiger beetle is a large group of beetles known for their aggressive predatory habits and running speed. They are used as biological insecticides in organic farming practices.

Green manure is organic substance that increases the fertility of soil. Crotalaria juncea is grown into and ploughed to soil that decompose and increase the fertility.

The biological control of agricultural pest, unlike chemical control is called self-perpetuating as biological control has power to renew or perpetuate oneself of itself for indefinite length of time.

The patient suffering from myocardial infraction is immediately given injection of Streptokinase. Streptokinase is an enzyme secreted by several species of streptococci that can bind and activate plasminogen used as effective and inexpensive thrombolysis medication in some cases of myocardial infraction.

Azolla is used as a biofertilizers because it has association of nitrogen fixing Cyanobacteria. They increase the fertility of soil without any chemical fertilizers.

Common cold is an infectious disease caused by virus. It cannot be controlled by antibiotics as antibiotics are not effective against viral disease.