CBSE Questions for Class 12 Medical Biology Microbes In Human Welfare Quiz 7 - MCQExams.com

A biofertilizer ________.
  • Is a substance which contains living microorganisms
  • Is symbiotic association of Azotobacter for fixing atmospheric nitrogen
  • Is a green manure
  • All of the above
Identify two correct statements from the following.
(i) Rennin is industrially produced by Mucor pusilus
(ii) Streptokinase is industrially produced by Pseudomonas pudica
(iii) Alkaline serine protease is produced by Bacillus licheniformis
(iv) DNA polymerase is produced by Trichoderma reesi.
  • i and ii
  • i and iii
  • ii and iii
  • ii and iv
A peculiar odour that occurs in marshy areas and cowsheds is due to gas produced by.
  • Cyanobacteria
  • Archaebacteria
  • Mycoplasma
  • Slime Moulds
In paddy fields, biological nitrogen fixation is chiefly brought about by.
  • Cyanobacteria
  • Green algae
  • Mycorrhiza
  • Rhizobium
Viruses of genus Nucleopolyhedrovirus are employed as.
  • Gobar gas producers
  • Biological control agents
  • Anaerobic sludge digesters
  • Antibiotics
  • Atmospheric nitrogen fixing agents
The microbe Pseudomonas denitrificans produces which vitamin?
  • K
  • D
  • $$B_2$$
  • $$B_{12}$$
Fungus used in preparing soy sauce is?
  • Agaricus
  • Aspergillus
  • Penicillium
  • Saccharomyces
Match the columns and choose the appropriate option.

III
(a)Citric acid(p)Methanobacterium
(b)Cyclosporin A(q)Monascus purpureus
(c)Statin(r)Aspergills niger
(d)Gobar gas(s)Trichoderma polysponum
(t)Clostridium butylicum
  • a-r, b-s, c-q, d-p
  • a-t, b-q, c-s, d-r
  • a-q, b-s, c-t, d-r
  • a-r, b-s, c-q, d-t
Microorganism used for commercial production of acetic acid is?
  • Saccharomyces cerevisiae
  • Acetobacter
  • Aspergillus niger
  • Clostridium butylicum
During biogas production acetic acid is transformed into the final product by the enzymes of ________
  • Clostridium
  • Pseudomonas
  • Penicillium
  • Methanobacillus
'Flocs' is?
  • Primary sludge produced in sewage treatment
  • A type of biofortified food
  • A mesh like structure formed by association of bacteria and fungal filaments in sewage treatment
  • The effluent in primary treatment tank obtained during sewage treatment
Identify the set which has all organisms used in biological control of pests.
  • Trichoderma, Nucleopolyhedro virus, Bacillus thuringiensis, Lady Bird (Lady Bug) beetle
  • Dragon flies, Bacillus thuringiensis, Lady Bird, Aphids
  • Lady Birds, Penicillium, Baculovirus, Aspergillus
  • Trichoderma, Aspergillus, Bacillus thuringiensis, Nucleopolyhedro virus
Which is wrongly matched?
  • Clostridium butylicum - Lipase - Removal of oil stains
  • Trichoderma polysporum - Cyclosporin A- Immunosuppressive drug
  • Monascus purpureus - Statins - Lowering of blood cholesterol
  • Streptococcus - Streptokinase - Removal of clot from blood vessel
The primary treatment of sewage water involves.
  • Sludge digestion
  • Aerobic bacterial activity
  • Anaerobic bacterial activity
  • Filtration and sedimentation
Identify the correct sequence of steps involved in the treatment of sewage.
(i)   Growth of aerobic microbes to reduce BOD
(ii)  Sequential filtration for removing floating debris
(iii) Production of inflammable gas
(iv) Growth of anaerobic microbes for digestion of bacteria
  • i, iv, ii, iii
  • ii, iv, i, iii
  • ii, i, iv, iii
  • iv, ii, iii, i
Vitamin $$B_{12}$$ is obtained from.
  • Propionibacteria
  • Ashbya gossypii
  • Bacillus subtilis
  • Saccharomyces cerevisiae
Identify the correct pair of characters of a bacterium which is used in the production of methane.
(i)   Recyclers of inorganic nutrients
(ii)  Present in stomach of cattle
(iii) Obtain energy from sunlight
(iv) Aerobes
  • ii, iii
  • i, ii
  • i, iv
  • iii, iv
Cyclosporin A, used as immunosuppressive agent in organ transplants is produced by.
  • Trichoderma
  • Monascus
  • Streptococcus
  • Staphylococcus
Match and find the correct option.

III
(i)Statins(a)Propionibacterium shermanii
(ii)Swiss cheese(b)Streptococcus
(iii)Cyolosporin A(c)Aspergillus niger
(iv)Citric acid(d)Trichoderma polysporum
(v)Clot buster(e)Monascus purpureus
  • i-e, ii-a, iii-d, iv-c, v-b
  • i-b, ii-a, iii-d, iv-e, v-c
  • i-e, ii-a, iii-b, iv-c, v-d
  • i-c, ii-e, iii-a, iv-d, v-b
  • i-e, ii-c, iii-a, iv-d, v-b
Match and find the correct combination.
(a)Fermenting malted cereals and fruit juice(i)Clots in Blood vessels
(b)Production of large holes in Swiss cheese(ii)Digestion of sludge by bacteria and fungi resulting in emission methane and other gases
(c)Myocardial infarction(iii)Production of ethanol
(d)Biogas(iv)Blood cholesterol lowering agent
(v)Production of large amount of CO$$_2$$
  • a-iii, b-v, c-iv, d-ii
  • a-i, b-ii, c-iii, d-iv
  • a-iii, b-v, c-i, d-ii
  • a-v, b-iv, c-iii, d-ii
Match and find the correct combination.
(a)Statin(i)Remove the clots in blood vessels
(b)Cyclosporin A(ii)Competitive inhibitor of cholesterol synthesizing enzyme
(c)Streptokinase(iii)Immunosuppressant
(d)Lipase(iv)Soap industry to remove oil stains
  • a-ii, b-iii, c-i, d-iv
  • a-iv, b-ii, c-iii, d-i
  • a-iii, b-ii, c-iv, d-i
  • a-iv, b-i, c-iii, d-ii
Identify the microorganism that produces biomass of proteins.
  • Monascus purpureus
  • Aspergillus niger
  • Methylophilus methylotropus
  • Trichloderma polysporum
Sewage water is purified by
  • Microorganisms
  • Light
  • Fishes
  • Aquatic plants
Supply of oxygen to biogas plant causes
  • Positive effect
  • Negative effect
  • No effect
  • None of the above
Treatment of polluted water is carried out with the help of ?
  • Lichens
  • Fungi
  • Ferns
  • Phytoplankton
Immunosuppressive cyclosporin A is obtained from
  • Aspergillus niger
  • Penicillium notatum
  • Monascus purpureus
  • Trichoderma poplysporum
Match the columns and find the correct option.
III
(a)Citric acid(i)Trichoderma
(b)Cyclosporin(ii)Clostridium
(c)Statins(iii)Aspergillus
(d)Butyric acid(iv)Monascus
  • a-iii, b-iv, c-i, d-ii
  • a-iii, b-i, c-ii, d-iv
  • a-iii, b-i, c-iv, d-ii
  • a-i, b-iv, c-ii, d-iii
Most abundant prokaryotes helpful to humans in making curd and antibiotics are
  • Archaebacteria
  • Cyanobacteria
  • Heterotrophic bacteria
  • Chemoautotrophs
Penicillin was first commercially prepared in
  • U.K.
  • France
  • U.S.A
  • Canada
Sesbania rostrate is preferred as green manure over other species because.
  • It grows quickly
  • It has extensive root system
  • It possesses nodules on both stem and roots
  • It possesses leaf nodules
Streptokinase is used for _______
  • Treating bacterial diseases
  • Preparation of cheese
  • Clearing blood clots
  • Clearing fruit juices
Azolla pinnate is allowed to grow in rice fields because.
  • It does not disturb photosynthesis of Rice plants
  • It provides food to fish
  • It provides aeration to standing water
  • It contains Anabaena
Which one of the following is associated with denitrification?
  • Rhizobium
  • Pseudomonas
  • Nitrobacter
  • Azotobacter
Sewage sludge is used as a
  • Manure
  • Biogas generator
  • Tipping
  • Both A and B
Which one of the following pairs serve as biofertilizers?
  • Albgo and Nostoc
  • Frankia and Nostoc
  • Pseudomonas and E.Coli
  • Aspergillus's and Actinomycetes
The most potent biofertilizer for sugarcane is?
  • Azotobacier
  • Acetobacrer
  • Clostridium
  • Rhizobium
In treatment of waste, biological treatment is
  • Primary treatment
  • Secondary treatment
  • Tertiary treatment
  • Reverse osmosis stage
Chlorination of treated waste water is required for
  • Killing all microbes
  • Removing suspended materials
  • Complete breakdown of organic matter
  • All of the above
Sewage is broken down in
  • Primary treatment
  • Secondary treatment
  • Tertiary treatment
  • All of the above
Selectable marker that provides resistance to the antibiotic kanamycin is?
  • Gentamycin acetyltransferase
  • Hygromycin phosphotransferase(hpt)
  • Streptomycine phosphotransferase
  • Neomycin phosphotransferase(npt $$11$$)
Which one of the following nitrogen fixing root nodule symbiotic is associated with the trees of Alnus and Casuarinas?
  • Rhizobium
  • Nostoc
  • Anabaena
  • Frankia
Which one is a biological in sewage treatment?
  • Primary treatment
  • Secondary treatment
  • Tertiary treatment
  • All of the above
Neurospora is a very good taxon for.
  • Biofertilizer
  • Biological control
  • Genetically studies
  • Antibiotics
Cyanobacteria helps farmers by
  • Reducing the alkanity of the soil
  • Reducing the acidity of the soil
  • Neutralising the alkanity of the soil
  • Water logging
Smack is chemically?
  • Diacetyl morphine
  • Diethyl morphine
  • Ethyl alcohol
  • $$3-4$$ Diacetylmorphine
Consider the following statements.
Mycorrhizal biotechnology has been used in rehabilitating degraded sites because mycorrhiza enables the plants to.
a. Resist drought and increase absorptive area
b. Tolerate extremes of pH.
c. Resist disease infestation
Of these statements.
  • $$2$$ and $$3$$ are correct
  • $$1$$ and $$2$$ are correct
  • $$1$$ and $$3$$ are correct
  • $$1, 2$$ and $$3$$ are correct
Which one is correct about the free living Rhizobium  sp. and its enzyme?
  • Bacteria are aerobic and nitrogenase are active
  • Bacteria are anaerobic and nitrogenase is active (operational)
  • Bacteria are aerobic and nitrogenase is inactive
  • Bacteria are anaerobic and nitrogenase is inactive
______ is a non-symbiotic aerobic nitrogen fixer.
  • Rhizobium
  • Nitrobacter
  • Clostridium
  • Psuedomonas
Choose the correct answers from the alternatives given.
A free-living bacterium capable of fixing nitrogen is:
  • Rhizobium
  • Streptococcus
  • Pseudamonas
  • Azotobacter
Biofertilizers are organisms which can bring about soil nutrient enrichment.
  • True
  • False
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