Health, Diseases & Vaccines MCQs for UPSC Prelims

93 practice questions on Health, Diseases & Vaccines from the Science & Technology section of the UPSC Prelims syllabus. 93 come with a written explanation and 25 are actual previous year questions. Try the sample set below - the answer stays hidden until you ask for it.

18 Easy 56 Medium 19 Hard 25 from past papers

Sample questions

Q1
Previous year question medium

Which of the following are the reasons for the occurrence of multi-drug resistance in microbial pathogens in India? 1. Genetic predisposition of some people 2. Taking incorrect doses of antibiotics to cure diseases 3. Using antibiotics in livestock farming 4. Multiple chronic diseases in some people Select the correct answer using the code given below.

  1. A 1 and 2
  2. B 2 and 3 only
  3. C 1, 3 and 4
  4. D 2, 3 and 4
Show answer and explanation

Correct answer: B - 2 and 3 only

Multi-drug resistance develops in the pathogens themselves, mainly because of misuse of antibiotics. Taking incorrect or incomplete doses lets resistant microbes survive and multiply (statement 2), and the widespread use of antibiotics in livestock farming drives resistance that can spread to humans (statement 3). The genetic predisposition of people and the presence of multiple chronic diseases relate to a person's vulnerability, not to the development of resistance in the microbes, so statements 1 and 4 are wrong. Hence 2 and 3 only is correct.

Q2
Previous year question medium

Which one of the following statements is not correct?

  1. A Hepatitis B virus is transmitted much like HIV.
  2. B Hepatitis B, unlike Hepatitis C, does not have a vaccine.
  3. C Globally, the number of people infected with Hepatitis B and C viruses are several times more than those infected with HIV.
  4. D Some of those infected with Hepatitis B and C viruses do not show the symptoms for many years.
Show answer and explanation

Correct answer: B - Hepatitis B, unlike Hepatitis C, does not have a vaccine.

The statement that Hepatitis B has no vaccine while Hepatitis C does is the reverse of the truth: a safe and effective vaccine exists for Hepatitis B, whereas there is no licensed vaccine for Hepatitis C, so this statement is not correct and is the answer. Hepatitis B does spread through blood, sexual contact and from mother to child, much like HIV; the combined global burden of Hepatitis B and C is indeed many times that of HIV; and both hepatitis infections can remain symptomless for years, so those statements are correct.

Q3
Previous year question medium

'Wolbachia method' is sometimes talked about with reference to which one of the following?

  1. A Controlling the viral diseases spread by mosquitoes
  2. B Converting crop residues into packing material
  3. C Producing biodegradable plastics
  4. D Producing biochar from thermochemical conversion of biomass
Show answer and explanation

Correct answer: A - Controlling the viral diseases spread by mosquitoes

The Wolbachia method refers to controlling mosquito-borne viral diseases, so option (a) is correct. Mosquitoes are infected with Wolbachia bacteria, which reduces their ability to transmit viruses like dengue, Zika and chikungunya. The method has nothing to do with converting crop residues, making biodegradable plastics, or producing biochar, so the other options are unrelated and incorrect.

Q4
Previous year question medium

A company marketing food products advertises that its items do not contain trans-fats. What does this campaign signify to the customers? 1. The food products are not made out of hydrogenated oils. 2. The food products are not made out of animal fats/oils. 3. The oils used are not likely to damage the cardiovascular health of the consumers. Which of the statements given above is/are correct?

  1. A 1 only
  2. B 2 and 3 only
  3. C 1 and 3 only
  4. D 1, 2 and 3
Show answer and explanation

Correct answer: C - 1 and 3 only

Industrial trans-fats are formed mainly by partial hydrogenation of vegetable oils, so a 'no trans-fat' claim implies the product is not made from such hydrogenated oils, making statement 1 correct. Trans-fats raise LDL and lower HDL cholesterol, so avoiding them reduces cardiovascular risk, making statement 3 correct. Statement 2 is wrong because animal fats also naturally contain small amounts of trans-fats (from ruminants), and more importantly being free of trans-fats does not mean the product avoids animal fats altogether; the two are not equivalent. Hence only 1 and 3 are correct.

Q5
Previous year question medium

What is the role of ultraviolet (UV) radiation in the water purification systems? 1. It inactivates/kills the harmful microorganisms in water. 2. It removes all the undesirable odours from the water. 3. It quickens the sedimentation of solid particles, removes turbidity and improves the clarity of water. Which of the statements given above is/are correct?

  1. A 1 only
  2. B 2 and 3 only
  3. C 1 and 3 only
  4. D 1, 2 and 3
Show answer and explanation

Correct answer: A - 1 only

Only statement 1 is correct. Ultraviolet radiation at germicidal wavelengths damages the DNA and RNA of bacteria, viruses and protozoa, inactivating or killing them, which is why UV lamps are used as a disinfection stage in water purifiers. Statement 2 is wrong because UV does not remove dissolved substances responsible for odour; that needs activated carbon or similar adsorbents. Statement 3 is wrong because UV has no effect on suspended solids, sedimentation or turbidity; clarity is improved by filtration, coagulation and settling, and turbid water actually reduces UV effectiveness by shielding microbes.

Q6
Previous year question medium

Improper handling and storage of cereal grains and oilseeds result in the production of toxins known as aflatoxins which are not generally destroyed by normal cooking process. Aflatoxins are produced by

  1. A bacteria
  2. B protozoa
  3. C moulds
  4. D viruses
Show answer and explanation

Correct answer: C - moulds

Aflatoxins are produced by moulds (fungi) of the genus Aspergillus, chiefly Aspergillus flavus and Aspergillus parasiticus, which grow on improperly stored cereals and oilseeds, so option (c) is correct. They are not produced by bacteria, protozoa or viruses, so options (a), (b) and (d) are wrong.

Q7
Previous year question medium

The term 'ACE2' is talked about in the context of

  1. A genes introduced in the genetically modified plants
  2. B development of India's own satellite navigation system
  3. C radio collars for wildlife tracking
  4. D spread of viral diseases
Show answer and explanation

Correct answer: D - spread of viral diseases

ACE2 (angiotensin-converting enzyme 2) is a receptor protein on human cell surfaces that the SARS-CoV-2 coronavirus uses to enter cells, so the term gained prominence in the context of the spread of viral diseases, option (d). It has nothing to do with genetically modified plant genes (a), India's NavIC satellite navigation system (b), or radio collars used in wildlife tracking (c). The COVID-19 pandemic made ACE2 a widely discussed term.

Q8
Previous year question medium

In the context of vaccines manufactured to prevent COVID-19 pandemic, consider the following statements: 1. The Serum Institute of India produced COVID-19 vaccine named Covishield using mRNA platform. 2. Sputnik V vaccine is manufactured using vector based platform. 3. COVAXIN is an inactivated pathogen based vaccine. Which of the statements given above are correct?

  1. A 1 and 2 only
  2. B 2 and 3 only
  3. C 1 and 3 only
  4. D 1, 2 and 3
Show answer and explanation

Correct answer: B - 2 and 3 only

Covishield, made by the Serum Institute of India, is based on a viral vector platform using an adenovirus, not an mRNA platform, so statement 1 is wrong. Russia's Sputnik V uses an adenoviral vector platform, so statement 2 is correct. Bharat Biotech's COVAXIN is an inactivated whole-virion vaccine, so statement 3 is correct. Hence only 2 and 3 are correct.

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