Tag: microbes in human welfare

Questions Related to microbes in human welfare

Primary sludge is used for

zoology microbes in human welfare biogas environmental use of microorganism microbes in waste treatment and biogas

  1. Preparation of compost

  2. Preparation of manure

  3. Biogas production

  4. All of the above

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Correct Option: D

Primary treatment of sewage is

zoology microbes in human welfare biogas environmental use of microorganism microbes in waste treatment and biogas

  1. Physical process

  2. Biological process

  3. Chemical process

  4. Biochemical process

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Correct Option: A

Sewage treatment process includes all of these features, except

zoology microbes in human welfare biogas environmental use of microorganism microbes in waste treatment and biogas

  1. A small part of the activate sludge is pumped back into the aeration tank to serve as incoculum

  2. Activated sludge cannot be used in anaerobic digestion process

  3. Anaerobic bacteria digest aerobic bacteria in sludge digesters

  4. Transfer of primary effluent in aeration tanks

Show answer
Correct Option: C
Explanation:

The process of removal and digestion of inorganic and organic waste present in the sewage water is called sewage treatment.

A. The flocs of bacteria obtained after treatment of the sewage water is called activated sludge. A small part of it is pumped back into the aeration tank which will act as inoculum and will multiply to start the digestion of organic compounds again.
B. Activated sludge can be anaerobic bacterium as well.
C. In sludge digesters, the digestion of organic compounds occurs.
D. Primary effluent is transferred to the aeration tanks for the purpose of digestion through aerobic bacteria.
Hence, the correct answer is 'Anaerobic bacteria digest aerobic bacteria in sludge digesters'.

Which one of the following is not a nitrogen-fixing organism ?

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  1. Anabaena

  2. Nostoc

  3. Azotobacter

  4. Pseudomonas

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Correct Option: D
Explanation:
Anabaena, Nostoc and Azolobacter help in nitrogen fixation. But Pseudomonas perform Denitrification which is the reduction of nitrates back into Nitrogen gas.
So, the correct option is 'Pseudomonas'

Which of the following statements is/are incorrect ?
(i) Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial habitats.
(ii) Anabaena, Nostoc and Oscillatoria are photosynthetic $N _2$ - fixing cyanobacteria.
(iii) Tolypothrix (BGA) can increase rice production by about 20%.
(iv) BGA add organic matter to the soil and increase its fertility.
(v) In our country, fertilizers are not available commercially in the markets for farmers.

zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

  1. (v) Only

  2. (iv) Only

  3. (iii) Only

  4. None of these

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Correct Option: A
Explanation:

Biofertilizers are available commercially in our country for farmers.

So, the correct option is '(v) Only'

Which of the following is widely used as a successful biofertiliser in Indian rice fields?

zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

  1. Rhizobium

  2. Acacia arabica

  3. Acalypha Indica

  4. Azolla pinnata

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Correct Option: D
Explanation:

Azolla pinnate is a small free-floating freshwater fern which is widely used as a biofertiliser in Indian rice fields. So, the correct answer is D.

Which one of the following microorganisms forms a symbiotic association with plants and helps them in their nutrition?

zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

  1. Glomus

  2. Azotobacter

  3. Klebsielfa

  4. Azospirillium

Show answer
Correct Option: A
Explanation:

Several fungi are known to form symbiotic associations with plants, i.e., mycorrhiza. The most common fungal partners of mycorrhiza are Glomus species.

Study the following statements and select the correct ones.


(i) Methanogens are archaebacteria that produce methane in marshy areas.
(ii) Nostoc is a filamentous blue-green alga which fixes atmospheric nitrogen.
(iii) Many members of the genus Glomus form mycorrhiza.

zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

  1. (i) and (ii)

  2. (i) and (iii)

  3. (ii) and (iii)

  4. (i), (ii) and (iii)

Show answer
Correct Option: C
Explanation:
1. Methanogens are archaebacteria belong to the domain of archaea, commonly found in wet, marshy areas,  They produce methane gas.
2. Nostoc is the filamentous blue-green alga. They form gelatin body which contains trichomes.
3. Glomus and it's all species form symbiotic relationships (mycorrhizas) with plant roots. 
So the correct answer is option D.

Which of the following statements is/are correct ?

zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

  1. In paddy fields, cyanobacteria serve as an important biofertiliser.

  2. Vermicompost consists of organic matter prepared by the action of earthworms on human or animal waste.

  3. The important examples of cyanobacteria as biofertilisers are Anabaena, Nostoc and Oscoilatoria.

  4. All of these

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Correct Option: B

Which of the following options includes biofertilisers ?

zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

  1. Cowdung manure and farmyard waste

  2. A quick growing crop ploughed back into the field

  3. Nostoc, Oscillatoria

  4. All of these

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Correct Option: A