Microbes in Human Welfare

NEET Biology · 80 questions · Page 5 of 8 · Click an option or "Show Solution" to reveal answer

Q41

In gobar gas, the maximum amount is that of :

A Propane

B Butane

C Methane

D Carbon dioxide

Correct Answer

Option C

Solution

In gobar gas the maximum amount is methane (50-70%) which is produced by methanogenic bacteria.

Q42

The domestic sewage in large cities is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)

A has very high amounts of suspended solids and dissolved salts

B has a high BOD as it contains both aerobic and anaerobic bacteria

C is processed by aerobic and then anaerobic bacteria in the secondary treatment in STPs

D does not really require the aeration step

Correct Answer

Option C

Solution

Sewage treatment includes physical, chemical, and biological processes.

Secondary treatment uses aerobic and anaerobic bacteria.

Q43

Consider the following statements - (a) Single cell Spirulina can produce large quantities of food rich in protein. (b) Body weight-wise Methylophilus methylotrophus may produce several times more proteins than cow. (c) Common button mushrooms are a very rich source of vitamin C. (d) A rice variety has been developed which is very rich in calcium. How many are correct?

A Statements (b), (c) and (d)

B Statements (c), (d)

C Statements (a), (c) and (d)

D Statements (a), (b)

Correct Answer

Option D

Solution

Spirulina is rich in protein, vitamins and minerals.

Methylophilus methylotrophus produces much more protein per gram than a cow.

Button mushrooms are rich in vitamin D not C.

The rice variety has high iron not calcium.

Q44

Monascus purpureus is a yeast used commercially in the production of :

A Ethanol

B Streptokinase for removing clots from the blood vessels

C Citric acid

D Blood cholesterol lowering statins

Correct Answer

Option D

Solution

Statins are produced by the yeast Monascus purpureus which have been commercialised as blood-cholesterol lowering agents.

It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.

Q45

Yeast is used in the production of

A Citric acid and lactic acid

B Lipase and pectinase

C Bread and beer

D Cheese and butter

Correct Answer

Option C

Solution

Saccharomyces cerevisiae is a yeast used in making bread (Baker's yeast) and commercial production of ethanol.

Q46

Which one of the following is an example of carrying out biological control of pests/diseases using microbes?

A Trichoderma sp. against certain plant pathogens

B Lady bird beetle against aphids in mustard

C Nucleopolyhedrovirus against white rust in Brassica

D Bt-cotton to increase cotton yield

Correct Answer

Option A

Solution

Trichoderma species are free living fungi that are very common in the root ecosystems.

They are effective biocontrol agents of several plant pathogens.

Q47

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

A Penicillin

B Streptokinase

C Cyclosporin-A

D Statins

Correct Answer

Option B

Solution

Streptokinase is immediately given to dissolve the thrombus causing myocardial infarction.

Q48

A nitrogen-fixing microbe associated with Azolla in rice fields is

A Tolypothrix

B Spirulina

C Frankia

D Anabaena

Correct Answer

Option D

Solution

Anabaena azollae resides in the leaf cavities of the fern Azolla.

It fixes nitrogen and part of the fixed nitrogen is excreted and becomes available to the fern.

Q49

Consider the following statements about organic farming: (A) Utilizes genetically modified crops like Bt cotton (B) Uses only naturally produced inputs like compost (C) Does not use pesticides and urea (D) Produces vegetables rich in vitamins and minerals. Which are correct?

A (B) and (C) only

B (B), (C) and (D)

C (C) and (D) only

D (A) and (B) only

Correct Answer

Option A

Solution

Organic farming relies on techniques like crop rotation, green manure, compost and biological pest control.

Q50

Which one of the following is a wrong matching of a microbe and its industrial product?

A Acetobacter aceti - acetic acid

B Clostridium butylicum - lactic acid

C Aspergillus niger - citric acid

D Yeast - statins

Correct Answer

Option B

Solution

Clostridium butylicum produces butyric acid, not lactic acid. Lactic acid is produced by Lactobacillus.

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