Microbes in Human Welfare NEET PYQs (2005–2026) with Solutions

10 solved Microbes in Human Welfare PYQs

Real NEET and AIPMT questions from this chapter, newest first. Try each one, then open the answer and the step-by-step explanation.

1. Question 1 (NEET 2026)

   NEET 2026EasyMicrobes in production of bioactive molecules

   Which of the following is used as a clot buster?

   1. AOption A: Streptokinase
   2. BOption B: Penicillin
   3. COption C: Cyclosporin A
   4. DOption D: Statins

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   Correct answer: (A) Streptokinase

   Explanation

   Streptokinase is produced by the bacterium Streptococcus and modified by genetic engineering. It is used as a 'clot buster' to remove clots from the blood vessels of patients who have had a myocardial infarction (heart attack). Penicillin is an antibiotic, Cyclosporin A (from the fungus Trichoderma polysporum) is an immunosuppressive agent used in organ-transplant patients, and statins (from the yeast Monascus purpureus) are blood-cholesterol-lowering agents. Hence the clot buster is Streptokinase, option (A).

2. Question 2 (NEET 2026)

   NEET 2026EasyHousehold Products

   What is the reason behind production of large holes in Swiss cheese?

   1. AOption A: Production of large amount of CO₂ by Propionibacterium sharmanii
   2. BOption B: Production of large amount of CO₂ by Clostridium butylicum
   3. COption C: Production of large amount of CO₂ and H₂ by lactic acid bacteria called Lactobacillus
   4. DOption D: Production of large amount of CO₂ and H₂ by Trichoderma polysporum

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   Correct answer: (A) Production of large amount of CO₂ by Propionibacterium sharmanii

   Explanation

   Large holes in Swiss cheese are produced due to CO₂ released by Propionibacterium sharmanii during fermentation.

3. Question 3 (NEET 2025)

   NEET 2025EasyMicrobes in human welfare

   Which one of the following is an example of non-distilled alcoholic beverage produced by yeast?

   1. AOption A: Whisky
   2. BOption B: Brandy
   3. COption C: Beer
   4. DOption D: Rum

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   Correct answer: (C) Beer

   Explanation

   Beer is a non-distilled alcoholic beverage produced by yeast fermentation. Whisky, brandy, and rum are distilled alcoholic beverages.

4. Question 4 (NEET 2025)

   NEET 2025MediumCancer, HIV and AIDS

   Which are correct: A. Computed tomography and magnetic resonance imaging detect cancers of internal organs. B. Chemotherapeutics drugs are used to kill non-cancerous cells. C. α-interferon activate the cancer patients' immune system and helps in destroying the tumour. D. Chemotherapeutic drugs are biological response modifiers. E. In the case of leukaemia blood cell counts are decreased. Choose the correct answer from the options given below:

   1. AOption A: B and D only
   2. BOption B: D and E only
   3. COption C: C and D only
   4. DOption D: A and C only

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   Correct answer: (D) A and C only

   Explanation

   Computed tomography (CT) and magnetic resonance imaging (MRI) are used to detect cancers of internal organs. α-interferon activates the immune system and helps destroy tumours. Chemotherapeutic drugs target cancerous cells, not non-cancerous cells, and biological response modifiers are different from chemotherapeutic drugs. In leukaemia, blood cell counts are generally abnormally high, not decreased.

5. Question 5 (NEET 2024)

   NEET 2024MediumBiocontrol

   Given below are two statements: Statement I : Bt toxins are insect group specific and coded by a gene cry IAc. Statement II : Bt toxin exists as inactive protoxin in B. thuringiensis. However, after ingestion by the insect the inactive protoxin gets converted into active form due to acidic pH of the insect gut. In the light of the above statements, choose the correct answer from the options given below:

   1. AOption A: Statement I is true but Statement II is false
   2. BOption B: Statement I is false but Statement II is true
   3. COption C: Both Statement I and Statement II are true
   4. DOption D: Both Statement I and Statement II are false

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   Correct answer: (A) Statement I is true but Statement II is false

   Explanation

   Bt toxins are insect group specific and coded by cry genes such as cryIAc, so Statement I is true. The protoxin is activated in the alkaline pH of the insect gut, not acidic pH, making Statement II false.

6. Question 6 (NEET 2023)

   NEET 2023EasyMicrobes

   Melonate inhibits the growth of pathogenic bacteria by inhibiting the activity of

   1. AOption A: Succinic dehydrogenase
   2. BOption B: Amylase
   3. COption C: Lipase
   4. DOption D: Dinitrogenase

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   Correct answer: (A) Succinic dehydrogenase

   Explanation

   Malonate acts as a competitive inhibitor of succinate dehydrogenase in the Krebs cycle, thereby inhibiting bacterial respiration and growth.

7. Question 7 (NEET 2023)

   NEET 2023EasyPollution

   Given below are two statements: Statement I: Electrostatic precipitator is most widely used in thermal power plant. Statement II: Electrostatic precipitator in thermal power plant removes ionising radiations. In the light of the above statements, choose the most appropriate answer from the options given below:

   1. AOption A: Both Statement I and Statement II are correct.
   2. BOption B: Both Statement I and Statement II are incorrect.
   3. COption C: Statement I is correct but Statement II is incorrect.
   4. DOption D: Statement I is incorrect but Statement II is correct.

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   Correct answer: (C) Statement I is correct but Statement II is incorrect.

   Explanation

   Electrostatic precipitators are widely used in thermal power plants to remove particulate matter from exhaust gases. They do not remove ionising radiations. Therefore, Statement I is correct and Statement II is incorrect.

8. Question 8 (NEET 2022)

   NEET 2022EasyBiofertilisers

   Which one of the following produces nitrogen fixing nodules on the roots of Alnus?

   1. AOption A: Beijerinckia
   2. BOption B: Rhizobium
   3. COption C: Frankia
   4. DOption D: Rhodospirillum

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   Correct answer: (C) Frankia

   Explanation

   Frankia is an actinomycete that forms nitrogen-fixing root nodules in non-leguminous plants such as Alnus.

9. Question 9 (NEET 2022)

   NEET 2022EasyImprovement in Food Production – Biofortification

   Breeding crops with higher levels of vitamins and minerals or higher proteins and healthier fats is called:

   1. AOption A: Bio-accumulation
   2. BOption B: Bio-magnification
   3. COption C: Bio-remediation
   4. DOption D: Bio-fortification

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   Correct answer: (D) Bio-fortification

   Explanation

   Biofortification refers to improving nutritional quality of crops by increasing vitamins, minerals, proteins, or healthy fats.

10. Question 10 (NEET 2022)

    NEET 2022MediumIndustrial Products

    Identify the microorganism which is responsible for the production of an immunosuppressive molecule cyclosporin A:

    1. AOption A: Streptococcus cerevisiae
    2. BOption B: Trichoderma polysporum
    3. COption C: Clostridium butylicum
    4. DOption D: Aspergillus niger

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    Correct answer: (B) Trichoderma polysporum

    Explanation

    Cyclosporin A is an immunosuppressive agent produced by the fungus Trichoderma polysporum.