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 Multiple Choice QuestionsMultiple Choice Questions

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11.

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

  • Spirulina

  • Anabaena

  • Frankia

  • Frankia

675 Views

12.

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

  • Trichoderma sp. against certain plant pathgens

  • Nucleopolyhedrovirus against white rust in Brassica

  • Bt-cotton to increase cotton yield

  • Bt-cotton to increase cotton yield

523 Views

13.

What gases are produced in anaerobic sludge digesters?

  • Methane and CO2 only

  • Methane hydrogen sulphide and CO2

  • Methane, hydrogen sulphide and O2

  • Methane, hydrogen sulphide and O2

515 Views

14.

In gobar gas, the maximum amount is that of

  • butane

  • methane

  • propane

  • propane

524 Views

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15.

Where do certain symbiotic microorganisms normally occur in human body?

  • Caecum

  • Oral lining and tongue surface

  • Vermiform appendix and rectum

  • Vermiform appendix and rectum

672 Views

16.

Consider the following four statements (a–d) and select the option which includes all the correct ones only:
Single cell Spirulina can produce large quantities of food rich in protein, minerals, vitamins etc.
Body weight-wise the microorganism Methylophilus methylotrophus may be able to produce several times more proteins than the cows per day.
Common button mushrooms are a very rich source of vitamin C.
A rice variety has been developed which is very rich in calcium.


  • Statements (III), (IV)

  • Statements (I), (III) and (IV)

  • Statements (II), (III) and (IV)

  • Statements (II), (III) and (IV)

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17.

Which of the followings is mainly produced by the activity of anaerobic bacteria on sewage?

  • Propane

  • Mustard gas

  • Marsh gas

  • Marsh gas

349 Views

18.

Which of the following helps in absorption of phosphorus from the soil by plants?

  • Rhizobium

  • Frankia

  • Anabaena

  • Anabaena

268 Views

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19.

Nitrifying bacteria

  • convert free nitrogen to nitrogen compounds

  • convert proteins into ammonia

  • reduce nitrates to free nitrogen 

  • reduce nitrates to free nitrogen 

229 Views

20.

Secondary sewage treatment is mainly a 

  • mechanical process

  • chemical process

  • biological process

  • biological process

318 Views

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