NEET Biology Microbes In Human Welfare MCQs Set A

Question: Which of the following microbe is made up of protein only?

• a) Prions
• b) Viroids
• c) Bacteria
• d) Virus

Answer: Prions

Question: The infectious agents made up of RNA only are

• a) Viroids
• b) Bacteria
• c) Fungi
• d) Virus

Answer: Viroids

Question:

• a)

  

  

• b)

  

  

• c)

  

  

• d) None of these

Answer:

Question: Microbial colonies

• a) More than one option is correct
• b) Can be seen by naked eyes
• c) Can be grown on nutritive media
• d) Are useful in study of microbes

Answer: More than one option is correct

Answer: What is the beneficial role of LAB in our stomach?

• a) Checks disease causing microbes
• b) It produces alkali which coagulate and partially digest the milk proteins
• c) Increases the amount of vitamin-D
• d) Causes souring of milk by decreasing nutritional quality

Answer: Checks disease causing microbes

Question: The microbe used for making bread is

• a) Saccharomyces cerevisiae
• b) Saccharomyces pireformis
• c) Saccharomyces ellipsoidens
• d) Saccharomyces sake

Answer: Saccharomyces cerevisiae

Question: Which of the following is traditional drink of some parts of southern India, made by fermenting sap from palms?

• a) Toddy
• b) Tea
• c) Beer
• d) Cashew apple

Answer:  Toddy

Question: Which of the following microbe is used for ripening of Swiss cheese?

• a) Propionibacterium sharmanii
• b) Penicillium roquefortii
• c) P. camembertii
• d) Streptomyces griseus

Answer: Propionibacterium sharmanii

Question: Production of beverages at industrial scale requires growing microbes in very large containers known as

• a) Fermentors
• b) Digesters
• c) Dough
• d) Concrete tank

Answer: Fermentors

Question: Find the odd one w.r.t. distilled alcoholic beverages

• a) Beer
• b) Rum
• c) Brandy
• d) Whisky

Answer: Beer

Question:  The chemicals which are “pro-life” with reference to human beings

• a) Can kill or retard the growth of disease-causing microbes
• b) Are produced by some plants and all animals
• c) Have rarely contributed to human welfare
• d) Are regarded as one of the most significant discovery of twenty first century

Answer: Can kill or retard the growth of disease-causing microbes

Question: Which of the following microbe is the source of first antibiotic?

• a) Penicillium notatum
• b) Staphylococci
• c) Aspergillus niger
• d) Bacillus brevis

Answer: Penicillium notatum

Question: The first antibiotic was discovered accidently by __A__ while working on __B__.

• a) A-Fleming; B-Staphylococci
• b) A-Fleming; B-Penicillium notatum
• c) A-Waksman ; B-Streptococcus
• d) A-Waksman; B-Bacillus brevis

Answer: A-Fleming; B-Staphylococci

Question: Commercial extraction of penicillin was done by

• a) More than one option is correct
• b) Ernest Chain
• c) Alexander Fleming
• d) Howard Florey

Answer:  More than one option is correct

Question:

• a) a(ii), b(i), c(iv), d(iii)
• b) a(iii), b(i), c(iv), d(ii)
• c) a(i), b(ii), c(iii), d(iv)
• d) a(ii), b(iv), c(iii), d(i)

Answer: a(ii), b(i), c(iv), d(iii)

Question: ________ are used in detergent formulations and are helpful in removing oily stains from laundry

• a) Lipases
• b) Pectinases
• c) Proteases
• d) Ligases

Answer: Lipases

Question: Select the microbe which is the source of ‘clot buster’ enzyme

• a) Bacterium; Streptococcus
• b) Fungi; Aspergillus niger
• c) Bacterium; Lactobacillus
• d) Fungi; Penicillium notatum

Answer: Bacterium; Streptococcus

Question: An immunosuppressive agent used in organ-transplant patients is

• a) Cyclosporin-A
• b) Lipases
• c) Statins
• d) Streptokinase

Answer: Cyclosporin-A

Question: The product of Monascus purpureus has been commercialised as

• a) Blood-cholesterol lowering agent
• b) Bottled juices clarifying agents
• c) Immunosuppressive agent
• d) Clot buster

Answer:  Blood-cholesterol lowering agent

Question: _________ are produced by yeast and act by competitively inhibiting the enzyme responsible for synthesis of cholesterol.

• a) Statins
• b) Alcohol
• c) Penicillin
• d) Cyclosporin-A

Answer: Statins

More Questions....................................

Question:  Treatment of waste-water is done by the

• a) Heterotrophic microbes naturally present in sewage
• b) Heterotrophic microbes inoculated in the sewage from outside only
• c) Chemoautotrophic microbes, naturally present in sewage
• d)Photoautotrophic microbes, naturally present in sewage

Answer: Heterotrophic microbes naturally present in sewage

Question: In a sewage treatment plant, primary treatment is

• a) Physical process which involves both filtration and sedimentation
• b) Physical process which involves sedimentation only
• c) Biological process which involves formation of primary sludge and effluent
• d) Biological process which involves both filtration and sedimentation

Answer: Physical process which involves both filtration and sedimentation

Question: During primary treatment, all solids that settle forms __A__ and the supernatant forms __B__.

• a) A - Primary sludge; B - effluent
• b) A - Activated sludge; B - clarified effluent
• c) A - Primary sludge; B - secondary effluent
• d) A - Activated sludge; B - effluent

Answer: A - Primary sludge; B - effluent

Question: What are flocs?

• a) Masses of aerobic bacteria associated with fungal filaments
• b) Masses of aerobic fungi only
• c) Masses of anaerobic bacteria and fungi
• d) Masses of anaerobic bacteria

Answer: Masses of aerobic bacteria associated with fungal filaments

Question:

• a) Secondary treatment
• b) Filtration and sedimentation
• c) Primary treatment
• d) Tertiary treatment

Answer: Secondary treatment

Question: What happens to activated sludge?

• a) The major part of the sludge is pumped into large tanks called anaerobic sludge digesters
• b) It undergoes sequential filtration
• c) It is completely pumped back into aeration tank to serve as inoculum
• d) It is generally released into natural water bodies like rivers and streams

Answer: The major part of the sludge is pumped into large tanks called anaerobic sludge digesters

Question: What is the composition of the biogas?

• a) Methane, carbon dioxide, hydrogen etc
• b) Methane, carbon dioxide, hydrogen, nitrogen dioxide etc
• c) Methane, carbon dioxide, oxygen etc
• d) Methane, carbon dioxide, sulphur dioxide etc.

Answer:  Methane, carbon dioxide, hydrogen etc

Question:

• a)

  

  

• b)

  

  

• c)

  

  

• d) None of these

Answer:

Question: The bacterium responsible for biogas production are collectively called

• a) Methanogens
• b) Thermoacidophiles
• c) Halophiles
• d) Cyanobacterium

Answer: Methanogens

Question: The technology of biogas production was developed in India mainly due to the efforts of

• a) IARI and KVIC
• b) IRRI
• c) ICAR
• d) IPM

Answer: IARI and KVIC

Question: The ladybird beetle and dragonflies are useful to get rid of _____ and _____ respectively

• a) Aphids and mosquitoes
• b) Mosquitoes and fruit borer
• c) Caterpillars and mosquitoes
• d) Mosquitoes and aphids

Answer:  Aphids and mosquitoes

Question: The effective biocontrol agents of several plant pathogens are species of

• a) Trichoderma
• b) Dragonflies
• c) Baculoviruses
• d) Baculoviruses

Answer: Trichoderma

Question:  Biofertilisers

• a) Include potash, phosphatic and nitrogenous organic and chemical compounds
• b) Are organisms that enrich the nutrient quality of soil
• c) Increase dependence on chemical fertilisers
• d) Are used regularly in the fields to deplete soil nutrients

Answer: Include potash, phosphatic and nitrogenous organic and chemical compounds

Question: The main sources of biofertilisers are

(a) Bacteria
(b) Cyanobacteria
(c) Fungi
(d) Protists

• a) (a), (b), (c)
• b) (a), (b), (d)
• c) (b), (c), (d)
• d) (a), (c), (d)

Answer:  (a), (b), (c)

Question: In paddy fields, _______ serves as an important biofertiliser

• a) BGA
• b) Rhizobium
• c) Glomus
• d) Frankia

Answer:  BGA

Question:

• a) A-Bacterial; B-Fungal
• b) A-Fungal; B-Algal
• c) A-Fungal; B-Bacterial
• d) A-Algal; B-Viral

Answer:  A-Bacterial; B-Fungal

Question:

• a) a(iv), b(iii), c(i), d(ii)
• b) a(i), b(iii), c(ii), d(iv)
• c) a(iii), b(iv), c(i), d(ii)
• d) a(iii), b(i), c(iv), d(ii)

Answer: a(iv), b(iii), c(i), d(ii)

Question: The fermented food of soyabean is

• a) All of these
• b) Sufu
• c) Tofu
• d) Tempeh

Answer:  All of these

Question: Dosa and Idli are fermented preparation of rice and black gram. The fermentation is done with

• a) More than one option is correct
• b) Streptococcus
• c) Leuconostoc
• d) Saccharomyces

Answer: More than one option is correct

Question: Read the following four statements (A – D) about certain mistakes in two of them :

(A) Dough, which is used for making foods such as dosa and idli is fermented by fungi and algae
(B) Toddy, a traditional drink of southern India is made by fermenting sap from palms.
(C) Large hole in 'Swiss cheese' are due to production of large amount of methane by Propionibacteriumsharmanii
(D) In our stomach, lactic acid bacteria play very beneficial role in checking disease - causing microbes
Which are the two statements having mistakes ?

• a) Statements (A) & (C)
• b) Statements (B) & (C)
• c) Statements (A) & (B)
• d) Statements (C) & (D)

Answer:  Statements (A) & (C)

Question:  Fermented beverage with maximum alcohol content is

• a) Brandy
• b) Whisky
• c) Gin
• d) Beer

Answer: Brandy

Question: Brewer’s yeast is used for ___A___ of malted cereals and fruit juices to produce ___B___.

• a) A - Fermentation; B - Alcohol
• b) A - Distillation; B - organic acid
• c) A - Distillation; B - CO₂
• d) A - Fermentation; B - CO

Answer: A - Fermentation; B - Alcohol

Question: Identify the correct statements w.r.t. antibiotics

(i) Fleming, Chain and Florey were awarded the Nobel prize in 1945
(ii) Antibiotics have greatly improved our capacity to treat deadly diseases
(iii) Penicillin was used to treat American soldiers wounded in World War I

• a) (i) and (ii)
• b) (i) and (iii)
• c) (ii) and (iii)
• d) All are correct

Answer: (i) and (ii)

Question: __A__ enzyme is used to remove clots from the blood vessels of patients who have undergone __B__ leading to heart attack.

• a) A-Streptokinase; B-Myocardial infraction
• b) A-Proteases; B-Myocardial infraction
• c) A-Lipases; B-Arteriosclerosis
• d) A-Pectinases; B-Atherosclerosis

Answer: A-Streptokinase; B-Myocardial infraction

Question: The bottled juices are clarified by the use of

• a) Both
• b) Proteases
• c) Pectinases
• d) None of these

Answer: Both

Question: Trichoderma polysporum is a source of

• a) Cyclosporin-A
• b) Streptokinase
• c) Statins
• d) Clot buster

Answer:  Cyclosporin-A

Question: Select the incorrect match

• a) Citric acid – Aspergillus flavus
• b) Clot buster – Streptococcus
• c) Cyclosporin A – Trichoderma
• d) Butyric acid – Clostridium butylicum

Answer: Citric acid – Aspergillus flavus

Question: Which fungal extract was extensively used in treating wounded American soldiers in world war-II?

• a) Penicillin
• b) Aflatoxin
• c) Gluconic acid
• d) Streptomycin

Answer: Penicillin

Question: The greater BOD of waste water relates

• a) Decreases oxygen content of water
• b) Increases oxygen content of water
• c) The decrease of temperature of water
• d) All of these

Answer: Decreases oxygen content of water

 Question: Ganga Action Plan for controlling pollution in Ganges started in

• a) 1985
• b) 1981
• c) 1987
• d) 1989

Answer: 1985

Question: All are correct w.r.t. BOD (Biochemical Oxygen Demand), except

• a) The greater the BOD of waste water, less is its polluting potential
• b) The BOD test is a measure of the organic matter present in the water
• c) Waste water is treated till BOD is reduced significantly
• d) It refers to the amount of oxygen that would be consumed if all the organic matter in one liter of water were oxidised by bacteria

Answer: The greater the BOD of waste water, less is its polluting potential

Question: The Ministry of Environment and Forest has initiated Ganga action plan and Yamuna action plan

(i) To save these major rivers of our country from pollution
(ii) It is proposed to build a large number of sewage treatment plants
(iii) Under these plans, only treated sewage may be discharged in the river

• a) All are correct
• b) (ii) and (iii) are correct
• c) (i) and (ii) are correct
• d) (i) and (iii) are correct

Answer: All are correct

Question: Secondary treatment of sewage

• a) Involves microbial digestion of organic matter
• b) Does not require aeration
• c) Involves shredding, churning, filtration and sedimentation
• d) Removes grit and large pieces of organic matter

Answer: Involves microbial digestion of organic matter

Question: The removal of floating and suspended solids from sewage through filtration and sedimentation is the part of

• a) Primary treatment
• b) Tertiary treatment
• c) Secondary treatment
• d) Biological treatment

Answer: Primary treatment

Question: Biogas contains

• a) 50% – 70% Methane
• b) 30% – 40% Methane
• c) 50% – 70% CO₂
• d) 20% Methane

Answer: 50% – 70% Methane

Question: First step in biogas production is carried out with the help of

• a) Decomposers
• b) Obligate aerobes
• c) Methanogens
• d) Parasites

Answer: Decomposers

Question:  Identify the incorrect statement w.r.t. biogas plant

• a) A floating cover is placed over the slurry, which keeps on rising as the gas is consumed in the tank
• b) It consists of a concrete tank, 10-15 feet deep in which bio-wastes are collected and a slurry of dung is fed
• c) It has an outlet, which is connected to pipe to supply biogas to nearby houses
• d) The spent slurry is removed and may be used as fertiliser

Answer: A floating cover is placed over the slurry, which keeps on rising as the gas is consumed in the tank

Question: Find the correct option (w.r.t. Bioherbicide)

• a) More than one option is correct
• b) Helianthus annus
• c) Cactoblastis cactorum
• d) Phytophthora palmivora

Answer: More than one option is correct

Question: Which of the following is included in biopesticide?

• a) Viruses, bacteria, fungi and protozoa
• b) Viruses and bacteria only
• c) Viruses, bacteria and fungi only
• d) Viruses, bacteria, fungi and protozoa only

Answer: Viruses, bacteria, fungi and protozoa

Question: Baculoviruses are/have

• a) Pathogens that attack insects and other arthropods
• b) Members of genus Nucleopolyhedrovirus that are never used as biocontrol
• c) Species-specific, broad spectrum insecticides
• d) Few negative impacts on plants, mammals, birds, fishes or even on non-target insects

Answer:  Pathogens that attack insects and other arthropods

Question: Identify the incorrect statement. 

(i) Bacillus thuringiensis are available in sachets as dried spores which are mixed with kerosine and sprayed on to vulnerable plants
(ii) B. thuringiensis are used to control butterfly caterpillars, but leave other insects unharmed
(iii) The toxin of B. thuringiensis is released in the blood of larvae and the larvae get killed
(iv) By the development of methods of genetic engineering B. thuringiensis toxin genes have been introduced into plants

• a) (i) and (iii)
• b) (ii) and (iv)
• c) (ii) and (iii)
• d) (i) and (ii)

Answer: (i) and (iii)

Question: Which of the following are natural insecticides?

(a) Rotenone (b) Pyrethrum
(c) Nicotine (d) Azadirachtin

• a) (a), (b), (c) & (d)
• b) (a) & (b) only
• c) (a), (c) & (d) only
• d) (a), (b) & (c) only

Answer: (a), (b), (c) & (d)

Question: Biofertilisers include

• a) Blue-green algae, Rhizobium, other nitrogen-fixing bacteria and mycorrhiza
• b) Blue-green algae, Trichoderma, Rhizobium and other nitrogen-fixing bacteria
• c) Rhizobium, other nitrogen-fixing bacteria, NPV and mycorrhiza
• d) Blue-green algae, Rhizobium, Bt and mycorrhiza

Answer: Blue-green algae, Rhizobium, other nitrogen-fixing bacteria and mycorrhiza

Question: Which of the following is not a symbiotic nitrogen fixing bacterium?

• a) Clostridium
• b) Frankia
• c) Rhizobium leguminosarum
• d) Mycobacterium

Answer: Clostridium

Question:  Which of the following is not the belief of an organic farmer?

• a) For controlling plant diseases and pests, chemicals like insecticides and pesticides should be used extensively
• b) The insects that are sometimes called pests are not eradicated, but instead are kept at manageable levels by a complex system of checks and balances within a living and vibrant ecosystem
• c) The more variety a landscape has, the more sustainable it is
• d) Eradication of the pests is undesirable because they act as food or hosts for beneficial predatory and parasitic insects

Answer: For controlling plant diseases and pests, chemicals like insecticides and pesticides should be used extensively

Question: The symbiotic association of fungi with plants is known as ____which is formed by many members of the fungal genus_____.

• a) Mycorrhiza; Glomus
• b) Mycorrhiza; Glomus
• c) Mycorrhiza; Penicillium
• d) Lichen; Rhizocarpon

Answer: Mycorrhiza; Glomus

Question:  Consider the following four statements (A - D) related to organic farming and select the correct option stating which ones are true (T) and which ones are false (F). The statements :

(A) Produces food crops rich in lipids, vitamins and iron
(B) Uses biofertilisers which increases soil fertility
(C) There is more use of chemical fertilisers and pesticides
(D) Raising unpolluted crops through the use of bacteria, fungi and cyanobacteria

• a)

  

  

• b)

  

  

• c)

  

  

• d) None of these

Answer:

Question: Concept of sustainable agriculture lies in

• a) Using spores of Bacillus thuringiensis for pest control
• b) Least use of biofertilizers
• c) A greater dependance on new crops
• d) Minimizing biopesticides

Answer: Using spores of Bacillus thuringiensis for pest control

Question: Which of the following statement for sewage is correct?

• a) Municipal waste-water, whose major component is human excreta
• b) Contains large amount of organic matter and non-pathogenic microbes
• c) Can be discharged directly into natural water bodies like rivers and streams
• d) It is generated in less quantities in cities and villages as compared to towns

Answer: Municipal waste-water, whose major component is human excreta

Question: Mark the mismatched pair

• a) Oscillatoria – Increase alkalinity of soil
• b) VAM – Biofertiliser
• c) Dragonfly – Biocontrol agent
• d) Anaerobic sludge digester – Biogas

Answer:Oscillatoria – Increase alkalinity of soil

Question:

• a) a(iii), b(iv), c(i), d(ii)
• b) a(iv), b(iii), c(ii), d(i)
• c) a(iv), b(ii), c(i), d(iii)
• d) a(iii), b(i), c(iv), d(ii)

Answer: a(iii), b(iv), c(i), d(ii)

Question: What gases are produced in anaerobic sludge digesters?

• a) Methane, Hydrogen sulphide and CO₂
• b) Hydrogen sulphide and CO₂
• c) Methane and CO₂ only
• d) Methane, Hydrogen sulphide and O₂

Answer: Methane, Hydrogen sulphide and CO₂

Question:  Besides paddy fields, cyanobacteria are also found inside vegetative part of

• a) Cycas
• b) Equisetum
• c) Psilotum
• d) Pinus

Answer: Cycas

Question: A good producer of citric acid is

• a) Aspergillus
• b) Saccharomyces
• c) Clostridium
• d) Pseudomonas

Answer: Aspergillus

Question: During sewage treatment, biogases are produced which include

• a) Methane, hydrogen sulphide, carbon dioxide
• b) Hydrogen sulphide, methane, sulphur dioxide
• c) Methane, oxygen, hydrogen sulphide
• d) Hydrogen sulphide, nitrogen, methane

Answer: Methane, hydrogen sulphide, carbon dioxide

Question: The domestic sewage in large cities

• a) Is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)
• b) Has a high BOD as it containing both aerobic and anaerobic bacteria
• c) When treated in STPs does not really require the aeration step as the sewage contains adequate oxygen
• d) Has very high amounts of suspended solids and dissolved salts

Answer: Is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)

Question: Monascus purpureus is a yeast used commercially in the production of

• a) Blood cholesterol lowering statins
• b) Ethanol
• c) Streptokinase for removing clots from the blood vessels
• d) Citric acid

Answer: Blood cholesterol lowering statins

Question: In Gobar gas, the maximum amount is that of

• a) Methane
• b) Butane
• c) Propane
• d) Carbon dioxide

Answer:  Methane

Question: Yeast is used in the production of

• a) Bread and beer
• b) Citric acid and lactic acid
• c) Cheese and butter
• d) Lipase and pectinase

Answer: Bread and beer

Question: A nitrogen fixing microbe associated with Azolla in rice fields is

• a) Anabaena
• b) Spirulina
• c) Tolypothrix
• d) Frankia

Answer: Anabaena