Microbes are put to work wherever fermentation turns a raw food into something more palatable or preservable. Curd forms when lactic acid bacteria (LAB), chiefly Lactobacillus, multiply in milk and convert it, the acid they produce coagulating and partially digesting the milk proteins; LAB also improve the nutritional quality of curd by increasing its Vitamin B12 content. The same princi
Microbes in Human Welfare
Class 1212 previous-year questions from this chapter every option and the correct answer, free · where the marks are
1. Microbes in household and industrial products
Exam focus: Beyond curd and bread, know the mechanism behind at least one product: statins from Monascus purpureus lower blood cholesterol by competitively inhibiting the enzyme that synthesises it — the kind of specific, mechanistic fact NEET prefers over a bare organism-product pairing.
Microbes in Household and Industrial Products
NCERT Wallah
Dedicated lecture on microbes used in household products (curd, dough, cheese) and industrial products (antibiotics, organic acids, enzymes) — a direct match.
ZoologyNEET 2025show ▾Which of the following microbes are not involved in the preparation of household products?
A. Aspergillus niger · B. Lactobacillus · C. Trichoderma polysporum · D. Saccharomyces cerevisiae · E. Propionibacterium sharmanii
Choose the correct answer from the options given below:
- A.A and B only
- B.A and C only✓
- C.C and D only
- D.C and E only
Solution
Lactobacillus (curd), Saccharomyces cerevisiae (bread, beverages) and Propionibacterium sharmanii (Swiss cheese) are household microbes. Aspergillus niger (citric acid) and Trichoderma polysporum (cyclosporin A) are industrial. Hence A and C.
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Save for spaced revision (free account)BotanyNEET 2025show ▾Streptokinase, produced by the bacterium Streptococcus, is used for:
- A.Curd production
- B.Ethanol production
- C.Liver disease treatment
- D.Removing clots from blood vessels✓
Solution
Streptokinase, from Streptococcus, is a 'clot buster' given to patients after a heart attack to dissolve blood clots in vessels.
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Save for spaced revision (free account)BotanyNEET 2025show ▾Which of the following is an example of a non-distilled alcoholic beverage produced by yeast?
- A.Whisky
- B.Brandy
- C.Beer✓
- D.Rum
Solution
Beer is fermented by yeast but not distilled. Whisky, brandy and rum are distilled spirits.
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Save for spaced revision (free account)BotanyNEET 2024show ▾Match List I with List II.
List I List II A. Clostridium butylicum I. Ethanol B. Saccharomyces cerevisiae II. Streptokinase C. Trichoderma polysporum III. Butyric acid D. Streptococcus sp. IV. Cyclosporin-A
Choose the correct answer from the options given below:
- A.A-II, B-IV, C-III, D-I
- B.A-III, B-I, C-IV, D-II✓
- C.A-IV, B-I, C-III, D-II
- D.A-III, B-I, C-II, D-IV
Solution
Clostridium butylicum gives butyric acid (III); Saccharomyces cerevisiae, ethanol (I); Trichoderma polysporum, cyclosporin-A (IV); Streptococcus, streptokinase (II).
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Save for spaced revision (free account)ZoologyNEET 2022show ▾Identify the microorganism which is responsible for the production of the immunosuppressive molecule cyclosporin A:
- A.Streptococcus cerevisiae
- B.Trichoderma polysporum✓
- C.Clostridium butylicum
- D.Aspergillus niger
The worked solution is part of a paid pack.
ZoologyNEET 2021show ▾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
Choose the correct answer from the options given below:
- A.(a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)✓
- B.(a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
- C.(a)-(ii), (b)-(iii), (c)-(i), (d)-(iv)
- D.(a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)
The worked solution is part of a paid pack.
BotanyNEET 2020show ▾Match the following columns and select the correct option.
Microbe Product (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.(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
- B.(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)✓
- C.(a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)
- D.(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
The worked solution is part of a paid pack.
BotanyNEET 2019show ▾Which of the following is a commercial blood-cholesterol-lowering agent?
- A.Cyclosporin A
- B.Statin✓
- C.Streptokinase
- D.Lipases
The worked solution is part of a paid pack.
BotanyNEET 2019show ▾Match the following organisms with the products they produce:
Column I Column II (a) Lactobacillus (i) Cheese (b) Saccharomyces cerevisiae (ii) Curd (c) Aspergillus niger (iii) Citric acid (d) Acetobacter aceti (iv) Bread (v) Acetic acid
- A.(a)-(ii), (b)-(iv), (c)-(v), (d)-(iii)
- B.(a)-(ii), (b)-(iv), (c)-(iii), (d)-(v)✓
- C.(a)-(iii), (b)-(iv), (c)-(v), (d)-(i)
- D.(a)-(ii), (b)-(i), (c)-(iii), (d)-(v)
The worked solution is part of a paid pack.
2. Sewage treatment, biogas, biocontrol and biofertilisers
Exam focus: Higher BOD means more polluted water, not cleaner — it measures how much oxygen bacteria would consume breaking down the organic matter present, so secondary (biological) treatment exists specifically to bring that number down before effluent is released.
Sewage Treatment, Biogas, Biocontrol Agents and Biofertilisers
Competition Wallah
Full-chapter one-shot whose later sections cover the sewage treatment plant, biogas production, biocontrol agents and biofertilisers in sequence; it also repeats household/industrial content already used for the sibling subtopic, since no single video covering just this half of the chapter was found.
BotanyNEET 2020show ▾Which of the following is put into the anaerobic sludge digester for further sewage treatment?
- A.Primary sludge
- B.Floating debris
- C.Effluents of primary treatment
- D.Activated sludge✓
The worked solution is part of a paid pack.
BotanyNEET 2019show ▾Select the correct group of biocontrol agents.
- A.Bacillus thuringiensis, Tobacco mosaic virus, Aphids
- B.Trichoderma, Baculovirus, Bacillus thuringiensis✓
- C.Oscillatoria, Rhizobium, Trichoderma
- D.Nostoc, Azospirillum, Nucleopolyhedrovirus
The worked solution is part of a paid pack.
BotanyNEET 2019show ▾Which of the following can be used as a biocontrol agent in the treatment of plant disease?
- A.Trichoderma✓
- B.Chlorella
- C.Anabaena
- D.Lactobacillus
The worked solution is part of a paid pack.