32 MICROBES IN HUMAN WELFARE QUESTIONS
MICROBES IN HUMAN WELFARE QUESTIONS
Which of the following statements is incorrect?
A) Besides microscopic plants and animals, microbes are the major components of biological systems on this earth
B) Microbes are present everywhere even in the harsh environments such as deep inside the geysers (thermal vents) where the temperature may be as high as 1000C.
C) Microbes are diverse–protozoa, bacteria, fungi and microscopic plant viruses, viroids and also prions.
D) Prions are proteinaceous non- infectious agents.
Which of the following statements is correct?
A) Microbes like protozoa can be grown on nutritive media to form colonies
B) Microbes can cause diseases in animals not plants.
C) Microbes are not found in highly acidic environments.
D) All microbes are not harmful; several microbes are useful to human beings in diverse ways.
Following is the image of a bacteriophage.
Which of the following options correctly labels its various parts?
A) I: Head, II: Neck, III: Collar B) I: Collar, II: Head, III: Tail
C) I: Collar, II: Tail, III: Head D) I: Tail, II: Collar, III: Head
The organisms responsible for converting milk into curd is-
A) Lactobacillus B) Propionibacterium sharmanii C) LAB D) Both (a) and (c)
Which of the following statements is not incorrect?
A) LAB produces acids that coagulate and completely digest the milk proteins.
B) A small amount of cheese is added to the fresh milk as inoculum or starter contain millions of LAB,
C) LAB multiply at a suitable temperature, thus converting curd to milk, which also improves its nutritional quality by increasing vitamin B12 in our stomach.
D) LAB plays very beneficial role in checking disease causing microbes.
The vitamin whose content increases during curd formation by lactic acid bacteria is
A) Vitamin C B) Vitamin D C) Vitamin B12 D) Vitamin E
The small amount of curd added to the fresh milk to convert it into curd is called
A) starter B) inoculum C) implant D) both (A) and (B)
How many of the following statements are correct?
I. The dough which is used for making food such as dosa and idli is also fermented by yeast.
II. The puffed-up appearance of dough is due to the production of CO2 gas.
III. The dough which is used for making bread, is fermented using brewer’s yeast
IV. ‘Toddy’, a traditional drink of some parts of Southern India is made by fermenting fruits from palms
V. Microbes are also used to ferment fishes, soyabean and bamboo-roots to make foods.
A) 4 B) 3 C) 2 D) 1
Choose the incorrect statement among the following.
A) Different varieties of cheese are known by their characteristic texture, flavour and taste, the specificity coming from the microbes used.
B) Large holes in ‘Swiss cheese’ are due to production of a large amount of 𝑆𝑂2 . by a bacterium named Propionibacterium sharmanii
C) The ‘Roquefort cheese’ are ripened by growing a specific fungi named Penicillium roqueforti which gives them a particular flavour.
D) Adenovirus is diamond like in structure and causes respiratory infections.
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
Big holes in Swiss cheese are made by a
A) a machine
B) methanogens
C) the bacterium Propionibacterium sharmanii producing a large amount of carbon dioxide
D) Lactobacillus
How many of the following beverages are produced by distillation of the fermented broth?
Whisky, wine, rum, brandy, beer
A) 5 B) 4 C) 3 D) 1
Which of the following statements is incorrect?
A) Very large vessels in which microbes are grown for the purpose of production of beverages and antibiotics on industrial scale are termed as fermenters
B) Microbes especially yeasts have been used from time immemorial for the production of beverages like wine, beer, whisky, brandy or rum
C) For this purpose the same yeast Saccharomyces cerevisiae used for bread-making and commonly called brewer’s yeast, is used for fermenting malted cereals and fruit juices, to produce ethanol
D) Antibiotics produced by microbes are regarded as one of the most significant discoveries of the 19th century and have greatly contributed towards the welfare of the human society
How many of the following statements are not incorrect?
I. Anti is a Greek word that means ‘against’, and bio means ‘life’, together they mean ‘against life’.
II. Antibiotics are chemical substances, which are produced by some microbes and can kill or retard the growth of other (disease-causing) microbes.
III. Penicillin is the first antibiotic to be discovered.
IV.Alexander Fleming discovered Penicillin while working on a Staphylococci bacteria.
The full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey.
A) 5 B) 4 C) 3 D) 1
Which of the following statements is correct?
A) Penicillin was used to treat American soldiers wounded in World War I.
B) Fleming, Chain and Florey were awarded the Nobel Prize in 1954, for this discovery.
C) Before Penicillin, antibiotics were also purified from other microbes
D) Antibiotics have greatly improved our capacity to treat deadly diseases such as plague, whooping cough, diphtheria and leprosy.
Microbes are used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes. Which of the following is incorrect regarding this?
A) Aspergillus – fungus – citric acid
B) Acetobacter aceti – bacteria – vinegar
C) Clostridium butylicum – protozoan- butyric acid
D) Lactobacillus – bacteria – lactic acid.
The substance which is used in detergent formulations and helpful in removing oily stains are –
A) Pectinases B) Proteases C) Lipases D) Statins
Bottled juices are clarified by the enzyme-
A) Pectinase and lipases B) Pectinase and peptidase C) Pectinase and protease D) Pectinase only
Match the following columns:
Which of the following is the correct option?
How many of the following statements are correct?
I. A bioactive molecule, cyclosporin A, is produced by the fungus Trichoderma polysporum
II. Statins are produced by the fungus Monascus purpureus.
III. Statins act by competitively inhibiting the enzyme responsible for synthesis of cholesterol.
IV. Streptokinase is used to remove clots from the blood vessels of patients who have undergone myocardial infarction leading to heart attack.
A) 3 B) 4 C) 2 D) 1
A good producer of citric acid is
A) Pseudomonas B) Clostridium C) Saccharomyces D) Aspergillus
Which of the following is correctly matched for the product produced by them?
A) Acetobacter aceti: Antibiotics B) Methanobacterium: Lactic acid
C) Penicillium notatum: Acetic acid D) Saccharomyces cerevisiae: Ethanol
Which of the following is wrongly matched in the given table?
Match Column-I with Column-II and select the correct option using the codes.
Which of the following is the correct option?
Match the following list of microbes and their importance: 
Which of the following is the correct option?
How many of the following are not incorrect with respect to wastewater treatment?
I. A major component of waste water is human excreta.
II. The municipal waste-water is called sewage which contains large amounts of inorganic matter and microbes. Many of which are pathogenic.
III. Sewage is treated in sewage treatment plants (STPs) to make it non- polluting.
IV. Treatment of waste water is done by the aerobic microbes naturally present in the sewage.
A) 4 B) 3 C) 2 D) 1
Which of the following statements is correct with respect to wastewater treatment?
A) Treatment of wastewater is carried out in three stages- Primary, Secondary and Biological Treatment.
B) Primary treatment basically involves physical removal of particles – large and small – from the sewage through sedimentation then filtration.
C) All solids that settle form the primary sludge, and the supernatant forms the effluent
D) The sludge from the primary settling tank is taken for secondary treatment.
Which of the following statements is incorrect with respect to wastewater treatment?
A) The primary effluent is passed into large aeration tanks where it is constantly agitated mechanically and air is pumped into This allows vigorous growth of useful aerobic microbes into flocs
B) Flocs are masses of bacteria associated with fungal filaments to form mesh like structures.
C) While growing, microbes consume the major part of the organic matter in the effluent. This significantly elevates the BOD (biochemical oxygen demand) of the effluent.
D) BOD refers to the amount of the oxygen that would be consumed if all the organic matter in one liter of water were oxidised by bacteria.
Which of the following statements is wrong with respect to wastewater treatment?
A) The BOD test measures the rate of uptake of oxygen by micro-organisms in the sample of water
B) BOD is a direct measure of the organic matter present in the water
C) The greater the BOD of waste water, more is its polluting potential
D) Once the BOD of sewage or waste water is reduced significantly, the effluent is then passed into a settling tank where the bacterial ‘flocs’ are allowed to sediment
The gases which evolve from the anaerobic sludge digester constituting biogas are
A) Methane, sulphur dioxide, carbon sulphide
B) Carbon dioxide, hydrogen chloride, methane
C) Methane, hydrogen chloride and carbon dioxide
D) Methane, carbon dioxide, hydrogen sulphide
Which of the following statement is wrong?
A) In settling tank, the sedimented bacterial flocs are called activated sludge
B) A small part of the activated sludge is pumped back into the anaerobic sludge digester to serve as the inoculum
C) In anaerobic sludge digesters, other kinds of bacteria which grow anaerobically, digest the bacteria and the fungi in the sludge
D) The biogas can be used as source of energy as it is inflammable
Which of the following statements is incorrect?
A) The effluent from the secondary treatment plant is generally released into natural water bodies like rivers and streams
B) Microbes play a major role in treating millions of gallons of waste water everyday across the This methodology has been practiced for more than a decade now, in almost all parts of the world.
C) Till date, no manmade technology has been able to rival the microbial treatment of sewage
D) The Ministry of Environment and Forests has initiated Ganga Action Plan and Yamuna Action Plan to save these major rivers of our country from pollution.
The primary treatment of wastewater removes
A) dissolved impurities
B) stable particles
C) methane
D) pathogens
Which of the following in sewage treatment removes suspended solids?
A) Tertiary treatment B) Secondary treatment C) Primary treatment D) Sludge treatment
Secondary sewage treatment is mainly a
A) physical process B) mechanical process C) chemical process D) biological process
BOD of wastewater is represented as
A) total inorganic matter B) biodegradable matter C) carbon dioxide evolution D) oxygen consumption
The high value of BOD (Biochemical Oxygen Demand) indicates that
A) water is pure.
B) water is highly polluted.
C) water is less polluted.
D) consumption of organic matter in the water is higher by microbes
If the activated sludge flocs do not get enough oxygen supply,
A) it will increase the rate of the treatment
B) the center of flocs will become anoxic, which would cause the death of bacteria and eventually breakage of flocs
C) it will increase the size of flocs.
D) protozoa would grow in large numbers
Methanogenic bacteria are not present in
A) gobar gas plant B) stomach of ruminants
C) bottom of water-logged paddy fields D) activated sludge
Activated sludge should settle quickly so that
A) it is rapidly pumped back from sedimentation tank to aeration tank
B) absorb pathogenic bacteria present in wastewater
C) it is anaerobically digested
D) absorbs inorganic matter
The sludge generated by wastewater treatment is treated by
A) anaerobic digesters B) floc
C) chemicals D) oxidation pond
What gases are produced in anaerobic sludge digesters?
A) Methane and CO2 only. B) Methane, Hydrogen sulfide and CO2.
C) Hydrogen Sulfide and CO2. D) Methane and CO2.
During sewage treatment, biogases are produced which include
A) hydrogen sulfide, nitrogen, methane B) methane, hydrogen sulfide, carbon dioxide
C) methane, oxygen and hydrogen sulfide D) hydrogen sulfide, methane and sulfur dioxide
The predominant gas in biogas is-
A) Methane B) Carbon dioxide C) Hydrogen sulphide D) ethane
Which of the following is incorrect with respect to production of biogas?
A) The type of the gas produced depends upon the microbes and the organic substrates they utilize
B) Certain bacteria, which grow anaerobically on cellulosic material, produce large amount of methane along with CO2 and N2
C) Methanogens are commonly found in the anaerobic sludge during sewage treatment, the common example is Methanobacterium.
D) Methanogens are also present in the rumen of cattle where they help in the breakdown of cellulose and play an important role in the nutrition of cattle.
The depth of concrete tank of biogas plant in which bio-wastes are collected and a slurry of dung is fed is
A) 10-12 meters B) 10-12 feet C) 10-15 meters D) 10-15 feet
How many of the following statements are incorrect?
I. The gobar gas is a special type of biogas generated from the dung of cattle.
II. A floating cover is placed over the slurry, which keeps on rising as the gas is produced in the tank due to the microbial activity.
III. A typical biogas plant has two main outlets, one for biogas which is used by nearby houses and the other for spent which may be used as fertilizer
IV. The technology of biogas production was developed in India mainly due to the efforts of IARI and KVIC.
V. Biogas plants are more often built in rural areas due to availability of large quantities of cattle dung and thus the biogas produced is used for cooking and lighting.
A) 5 B) 4 C) 3 D) none
IARI stands for
A) Indian Academy of Research and Intelligence B) International Agricultural Research Institute
C) Indian Agricultural Research Institute D) International Academy of Research and Intelligence
KVIC stands for –
A) Khadi and Village Industries Company B) Kisan and Village Industries Company
C) Khadi and Village Industries Commission D) Khadi and Village Interest Commission
Select the correct option among the following
A) A – slurry, B – Digester, C – Gas Holder, D – Sludge
B) A – sludge, C – Gas mixture, B – Slurry, D – Water + Dung
C) A – sludge, B – Digester, C – Gas Holder, D – Slurry
D) A – slurry, C – Gas mixture, B – Sludge, D – Water + Dung
Which of the following is mainly produced by the activity of anaerobic bacteria on sewage?
A) Propane B) Mustard gas C) Marsh gas D) Laughing gas
Which of the following statements about methanogens is not correct?
A) They produce methane gas.
B) They can be used to produce biogas.
C) They are found in the rumen of cattle and their excreta.
D) They grow aerobically and breakdown cellulose-rich food
Select the correct statement from the following
A) Activated sludge-sediment in settlement tanks of the sewage treatment plant is a rich source of aerobic bacteria.
B) Methanobacterium is an aerobic bacterium found in the rumen of cattle.
C) Biogas is produced by the activity of aerobic bacteria on animal waste
D) Biogas, commonly called gobar gas, is pure methane
The use of biological methods for controlling plant disease and pest is known as –
A) Bioinvestment B) Bioremediation C) Biofortification D) Biocontrol
How many of the following statements are incorrect?
I. In agriculture, there is a method of controlling pests that relies on natural predation rather than introduced chemicals.
II. A key belief of the organic farmer is that biodiversity furthers health.
III. The conventional farming practices rarely used chemical methods to kill both useful and harmful life forms indiscriminately
IV. The organic farmer holds the view that the eradication of the creatures that are often described as pests is not only possible, but also undesirable.
A) 4 B) 3 C) 2 D) 1
In a system of checks and balances-
A) The insects that are sometimes called pests are completely eradicated.
B) All insects are eradicated.
C) When pests are beyond manageable levels, they are completely eradicated.
D) Pests are not eradicated but they are kept at manageable levels.
The biopesticide used to get rid of aphids is
A) Dragonflies B) Baculoviruses
C) Ladybird D) Bacillus thuringiensis
Microbial biocontrol agent that can be introduced in order to control butterfly caterpillar is-
A) Fungus Trichoderma B) Bacillus tracin
C) Baculoviruses D) Bacillus thuringiensis
The bacteria bacillus thuringiensis is available in the market in the form of
A) Tablets B) Powder C) Spores D) Gel form
Which of the following statements is incorrect?
A) Eradication of the pests is undesirable as without them the beneficial predatory and parasitic insects which depend upon them as food or hosts would not be able to survive.
B) An important part of the biological farming approach is to become familiar with the various life forms that inhabit the field, predators as well as pests, and also their life cycles, patterns of feeding and the habitats that they prefer.
C) The very familiar beetle with red and black markings is the Ladybird
D) Bt spores are mixed with water and sprayed onto valuable plants such as brassicas and fruit trees, where these are eaten by the insect adults
How many of the following are correct with respect to Trichoderma?
I. Developed for use in the treatment of plant diseases
II. It’s species are free living fungi that are very common in root ecosystems.
III. It belongs to the division Ascomycetes
IV. They are very effective biocontrol agents for several plant pathogens.
A) 4 B) 3 C) 2 D) 1
How many of the following are correct with respect to baculoviruses?
I. They are pathogens that attack insects and other arthropods.
II. The majority of baculoviruses used as biological control agents are in the family nucleopolyhedrovirus.
III. These viruses are excellent candidates for species-specific, narrow spectrum insecticidal applications.
IV. They have been shown to have no negative impacts on plants, mammals, birds, fish or even on non-target insects
V. This is especially desirable when beneficial insects are being conserved to aid in an overall integrated pest management programme, or when an ecologically sensitive area is being treated.
A) 5 B) 4 C) 3 D) 2
Which one of the following is not an example of carrying out biological control of pests/diseases using microbes?
A) Ladybird beetle against aphids in mustard.
B) Bt-cotton to increase cotton yield.
C) Nucleopolyhedrovirus against white rust in Brassica. D) Trichoderma against certain plant pathogens.
Match the items in Column-I and Column-II and choose the correct answer.
Which of the following is the correct option? 
Which of the following is incorrect?
A) Biofertilizers are organisms that enrich the nutrient quality of the soil.
B) Realising the problems associated with the overuse of chemical fertilisers, there is a large pressure to switch to organic farming – the use of biofertilisers.
C) The main sources of biofertilisers are bacteria, fungi, protozoans and cyanobacteria.
D) In the root nodules of leguminous plants, symbiotic association is formed by Rhizobium
The fungal symbiont in mycorrhiza association absorbs ______from soil and passes it to the plant.
A) N B) N and K C) P D) Ca
How many of the following are correct with respect to mycorrhiza?
I. Fungi are also known to form symbiotic associations with plants (mycorrhiza).
II. Many members of the genus Glomus form mycorrhiza.
III. It provide resistance to root-borne pathogens.
IV. It provide tolerance to salinity and drought.
V. It helps in overall increase in plant growth and development.
A) 5 B) 4 C) 3 D) 1
Which of the following is incorrect?
A) Rhizobium fixes atmospheric nitrogen into inorganic forms which are used by plants as nutrients.
B) Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen.
C) Blue green algae add organic matter to the soil and increase its fertility.
D) In paddy fields, cyanobacteria serve as an important biofertiliser.
The bacteria which can fix atmospheric nitrogen in it’s free-living form in the soil are
A) Azospirillum and Azorhizobium B) Azospirillum and Azotobacter
C) Azotobacter and Rhizobium D) Frankia and Azospirillum
Which one of the following microbes form a symbiotic association with plants and helps them in their nutrition?
A) Azotobacter B) Aspergillus C) Glomus D) Trichoderma
Which one of the following helps in the absorption of phosphorus from the soil by plants?
A) Anabaena B) Glomus C) Rhizobium D) Frankia
Which of the following is not a biofertilizer?
A) Rhizobium B) Nostoc C) Mycorrhiza D) Agrobacterium
Conversion of milk to curd improves its nutritional value by increasing the amount of :
(a) Vitamin D (b) Vitamin A (c) Vitamin E (d) Vitamin B12
Which of the following in sewage treatment removes suspended solids?
(a) Secondary treatment (b) Primary treatment
(c) Sludge treatment (d) Tertiary treatment
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
The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, include the:
(a) Halophiles (b) Thermoacidophiles (c) Methanogens (d) Eubacteria
Which of the following is wrongly matched in the given table?
Microbe Product Application
(a) Trichoderma polysporum Cyclosporin A immunosuppressive drug
(b) Monascus purpureus Statins lowering of blood cholesterol
(c) Streptococcus Streptokinase removal of clot from blood vessel
(d) Clostridium butylicum Lipase removal of oil stains
The guts of cow and buffalo possess:
(a) Chlorella spp (b) Methanogens (c) Cyanobacteria (d) Fucus spp
Match the following list of microbes and their importance
Saccharomyces cerevisiae (i) Production of immunosuppressive agents
Monascus Purpureus (ii) Ripening of Swiss cheese
Trichoderma polysporum (iii) Commercial production of ethanol
Propionibacterium sharmanii (iv) Production of blood cholesterol lowering agents
(a) A – (iv); B – (iii); C – (ii); D – (i) (b) A – (iv); B – (ii); C – (i); D – (iii)
(c) A – (iii); B – (i); C – (iv); D – (ii) (d) A – (iii); B – (iv); C – (i); D – (ii)
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
Which one of the following equipment is essentially required for growing microbes on a large scale, for industrial production of enzymes?
(1) BOD incubator (2) Sludge digester (3) Industrial oven (4) Bioreactor
Match the following organisms with the products they produce :-
(a) Lactobacillus (i) Cheese
(b) Saccharomyces (ii) Curd cerevisiae
(c) Aspergillus niger (iii) Citric Acid
(d) Acetobacter aceti (iv) Bread
(v) Acetic Acid
Select the correct option.
(a) (b) (c) (d) (a) (b) (c) (d) (a) (b) (c) (d) (a) (b) (c) (d)
(1) (ii) (iv) (v) (iii) (2) (ii) (iv) (iii) (v) (3) (iii) (iv) (v) (i) (4) (ii) (i) (iii) (v)
Which of the following can be used as a biocontrol agent in the treatment of plant disease?
(1) Trichoderma (2) Chlorella (3) Anabaena (4) Lactobacillus
Which of the following is a commercial blood cholesterol lowering agent?
(1) Cyclosporin A (2) statin (3) Streptokinase (4) Lipases
Select the correct group of biocontrol agents.
(1) Bacillus thuringiensis,Tobacco mosaic virus, Aphids
(2) Trichoderma, Baculovirus, Bacillus thuringiensis
(3) Oscillatoria, Rhizobium, Trichoderma
(4) Nostoc, Azospirillium, Nucleopolyhedrovirus
A biocontrol agent to be a part of an integrated pest management should be
(1) Species-specific and symbiotic (2) Free living and broad spectrum
(3) Narrow spectrum and symbiotic (4) Species-specific and inactive on non-target organisms
Which of the following statements about methanogens is not correct?
(1) They can be used to produce biogas.
(2) They are found in the rumen of cattle and their excreta
(3) They grow aerobically and breakdown cellulose-rich food.
(4) They produce methane gas.
Among the following pairs of microbes, which pair has both the microbes that can be used as biofertilizers?
(1) Aspergillus and Rhizopus (2) Rhizobium and Rhizopus
(3) Cyanobacteria and Rhizobium (4) Aspergillus and Cyanobacteria
Which of the following is put into anaerobic sludge digester for further sewage treatment?
1) Activated sludge 2) Primary sludge 3) Floating debris 4) Effluents of primary treatment
Match the following columns and select the correct option
Column-I Column-II
a) Clostridium butylicum i) Cyclosporin-A
b) Trichoderma polysporum ii) Butyric acid
c) Monascus purpureus iii) Citric acid
d) Aspergillus niger iv) Blood cholesterol lowering agent
a b c d a b c d
1) iv iii ii I 2) iii iv ii i
3) ii i iv iii 4) i ii iv iii
19) Match List-I with List-II
List-I |
List-II |
||||
| (a) | Aspergillus niger | (i) | Acetic Acid | ||
| (b) | Acetobacter aceti | (ii) | Lactic Acid | ||
| (c) | Clostridium butylicum | (iii) | Citric Acid | ||
| (d) | Lactobacillus | (iv) | Butyric Acid | ||
(a) (b) ( c) (d)
1) (i) (ii) (iii) (iv)
2) (ii) (iii) (I) (iv)
3) (iv) (ii) (i) (iii)
4) (iii) (i) (iv) (ii)
Identify the microorganism which is responsible for the production of an immunosuppressive molecule cyclosporine A:
1) Trichoderma polysporum 2) Clostridium butylicum
3) Aspergillus niger 4) Streptococcus cerevisiae