Biology Objective Questions and Answers: Chapter 08 Microbes in Human Welfare
Explore reliable objective questions for Chapter 08 Microbes in Human Welfare tailored for Class 12 learners. Utilizing these Biology multiple-choice formats ensures thorough preparation and strengthens problem-solving speed for upcoming school assessments.
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Question: The technology of biogas production from cow dung was developed in India largely due to the efforts of
a) Indian Agricultural Research Institute and Khadi & Village Industries Commission
b) Indian Oil Corporation
c) Oil and Natural Gas Commission
d) Gas Authority of India
Answer : A
Question : The free-living fungus Trichoderma can be used for
a) biological control of plant diseases
b) controlling butterfly caterpillars
c) producing antibiotics
d) killing insects
Answer : A
Question : What would happen if oxygen availability to activated sludge flocs is reduced?
a) The center of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs
b) Flocs would increase in size as anaerobic bacteria would grow around flocs
c) Protozoa would grow in large numbers
d) It will slow down the rate of degradation of organic matter
Answer : A
Question : Mycorrhiza does not help the host plant in
a) Increasing its resistance to insects
b) Enhancing its resistance to root pathogens
c) Increasing its tolerance to drought
d) Enhancing its phosphorus uptake capacity
Answer : A
Question : Which one of the following is not a nitrogen-fixing organism?
a) Pseudomonas
b) Azotobacter
c) Nostoc
d) Anabaena
Answer : A
Question : Which of the following microbes are used for the commercial production of citric acid?
a) Aspergillus
b) Asparagus
c) Asparagine
d) All of these
Answer : A
Question : Saccharomyces cerevisiae is used primarily for
a) Baking
b) Bleaching
c) Biofuel
d) None of these
Answer : A
Question : Which of the following is mainly produced by the activity of aerobic bacteria on sewage
a) March gas
b) Laughing gas
c) Mustard gas
d) Propane
Answer : A
Question : Select the correct statement from the following
a) Activated sludge sediment is dettlement tanks of sewage treatment plant is rich source of aerobic bacteria
b) Biogas is produced by the activity of aerobic bacteria on animal waste
c) None of these
d) Biogas commnly called gobar gas in pure methane
Answer : A
Question : Secondary sewage tretment is mainly a
a) Biological process
b) Chemical proces
c) Mechanical process
d) Physical proces
Answer : A
Question : The vitamin whose content increases following the conversion of milk into curd by lactic acid bacteria is
a) vitamin B12
b) vitamin E.
c) vitamin D
d) vitamin C
Answer : A
Question : Wastewater treatment generates a large quantity of sludge, which can be treated by
a) oxidation pond
b) chemicals
c) digesters
d) activated sludge
Answer : A
Question : The primary treatment of waste water involves the removal of
a) stable particles
b) toxic substances
c) harmful bacteria
d) dissolved impurities
Answer : A
Question : BOD of waste water is estimated by measuring the amount of
a) oxygen consumption
b) oxygen evolution
c) biodegradable organic matter
d) total organic matter
Answer : A
Question : Which one of the following alcoholic drinks is produced without distillation?
a) Wine
b) Whisky
c) Rum
d) Brandy
Answer : A
Question : Which of these processes does not give off CO2?
a) Lactate fermentation
b) Aerobic respiration
c) Alcoholic fermentation
d) None of these
Answer : A
Question : High biological oxygen demand in a water body means
a) Water is polluted
b) Water is not polluted
c) Waterbody contains lots of lifeforms
d) None of these
Answer : A
Question : The guts of various ruminants contain
a) Methanogens
b) Halophiles
c) Borth
d) None of these
Answer : A
Question : Roquefort cheese’ is ripened by using a
(a) bacterium
(b) yeast
(c) cyanobacteria
(d) fungus.
Answer : D
Question : The puffed-up appearance of dough is due to fermentation by bacteria. Identify the gas liberated during the process.
(a) Hydrogen sulphide
(b) Methane
(c) Ammonia
(d) Carbon dioxide
Answer : D
Question : 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.
Answer : D
Question : Which among these are produced by distillation of fermented broth?
(i) Whisky
(ii) Wine
(iii) Beer
(iv) Rum
(v) Brandy
(a) (ii) and (iii) only
(b) (i) and (ii) only
(c) (iii) and (v) only
(d) (i), (iv) and (v) only
Answer : D
Question : Match the microbes in column I with their commercial/industrial products in column II and choose the correct answer.
A. Aspergillus niger 1. Ethanol
B. Clostridium butylicum 2. Statins
C. Saccharomyces cerevisiae 3. Citric acid
D. Trichoderma polysporum 4. Butyric acid
E. Monascus purpureus 5. Cyclosporin A
(a) A – 4, B – 5, C – 2, D – 1, E – 3
(b) A – 5, B – 4, C – 1, D – 2, E – 3
(c) A – 3, B – 4, C – 1, D – 5, E – 2
(d) A – 3, B – 4, C – 5, D – 1, E – 2
Answer : C
Question : Select the correct group of biocontrol agents.
(a) Nostoc, Azospirillum, Nucleopolyhedrovirus
(b) Bacillus thuringiensis, Tobacco mosaic virus, Aphids
(c) Trichoderma, Baculovirus, Bacillus thuringiensis
(d) Oscillatoria, Rhizobium, Trichoderma
Answer : C
Question : Which of the following in sewage treatment removes suspended solids?
(a) Secondary treatment
(b) Primary treatment
(c) Sludge treatment
(d) Tertiary treatment
Answer : B
Question : What gases are produced in anaerobic sludge digesters?
(a) Methane and CO2 only
(b) Methane, Hydrogen sulphide and CO2
(c) Methane, Hydrogen sulphide and O2
(d) Hydrogen sulphide and CO2
Answer : B
Question : The domestic sewage in large cities
(a) has a high BOD as it contains both aerobic and anaerobic bacteria
(b) is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)
(c) when treated in STPs does not really require the aeration step as the sewage contains adequate oxygen
(d) has very high amount of suspended solids and dissolved salts.
Answer : B
Question : When domestic sewage mixes with river water
(a) small animals like rats will die after drinking river water
(b) the increased microbial activity releases micronutrients such as iron
(c) the increased microbial activity uses up dissolved oxygen
(d) the river water is still suitable for drinking as impurities are only about 0.1%.
Answer : C
Question : Which one of the following is not used in organic farming?
(a) Glomus
(b) Earthworm
(c) Oscillatoria
(d) Snail
Answer : D
Question : Refer to the given diagram and choose the correct option for it.
(a) Bacteriophage - Tobacco mosaic disease
(b) Adenovirus - Respiratory disease
(c) Viroid - Potato spindle tumour disease
(d) Prion - Alzheimer’s disease
Answer : B
Question : Select the correct statement.
(a) Acetobacter aceti produces citric acid.
(b) Saccharomyces cerevisiae is used as clot buster.
(c) Penicillium notatum restrict the growth of Staphylococci.
(d) Methanogens are found in aerobic conditions.
Answer : C
Question : In gobar gas, the maximum amount is that of
(a) butane
(b) methane
(c) propane
(d) carbon dioxide.
Answer : B
Question : Which of the following can be used as a biocontrol agent in the treatment of plant disease?
(a) Lactobacillus
(b) Trichoderma
(c) Chlorella
(d) Anabaena
Answer : B
Question : The microbial biocontrol agent for butterfly caterpillar is
(a) Bacillus thuringiensis
(b) Saccharomyces
(c) Lactobacillus
(d) Cyanobacteria
Answer : A
Question : Which of the following is correctly matched for the product produced by them?
(a) Methanobacterium : Lactic acid
(b) Penicillium notatum : Acetic acid
(c) Saccharomyces cerevisiae : Ethanol
(d) Acetobacter aceti : Antibiotics
Answer : C
Question : A biocontrol agent to be a part of an integrated pest management should be
(a) species-specific and symbiotic
(b) free living and broad spectrum
(c) narrow spectrum and symbiotic
(d) species-specific and inactive on non-target organisms.
Answer : D
Question : In biogas plant, the role of acidogenic bacteria is to
(a) convert monomers to organic acids
(b) convert monomers to complex polymers
(c) transform acetic acid to biogas
(d) digest fungi in the sludge.
Answer : A
Question : Which of the following bacteria converts milk into curd ?
(a) Propionibacterium
(b) Lactobacillus
(c) Streptococcus
(d) Bacillus
Answer : B
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Chapter 08 Microbes in Human Welfare Objective Questions & Solutions for Class 12 Biology
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FAQs
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