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UPSC CSE Prelims 2020 — Science & Technology Questions with Answers

All 12 Science & Technology previous-year questions from UPSC CSE Prelims 2020, each with the correct answer and a full explanation. Practise them as a free, timed mock test with instant scoring.

1. Q1.Biotechnology

   In the context of recent advances in human reproductive technology, 'Pronuclear Transfer' is used for

   • a)Fertilization of egg in vitro by the donor sperm
   • b)Genetic modification of sperm-producing cells
   • c)Development of stem cells into functional embryos
   • d)Prevention of mitochondrial diseases in offspring

   Explanation: Pronuclear transfer is a mitochondrial replacement technique used to prevent the transmission of mitochondrial diseases from mother to child.

2. Q2.Artificial Intelligence

   With the present state of development, Artificial Intelligence can effectively do which of the following?

   • a)1, 2, 3, 4 and 5
   • b)1, 3 and 4 only
   • c)2, 4 and 5 only
   • d)1, 2, 3, 4 and 5 (none excluded)

   Explanation: AI can optimize industrial energy use, diagnose disease and do text-to-speech, but creating genuinely meaningful creative works and wireless transmission of electrical energy are not capabilities of AI, so the answer is 1, 3 and 4 only.

3. Q3.Communication Technology

   With reference to Visible Light Communication (VLC) technology, which of the following statements are correct?

   • a)1, 2 and 3 only
   • b)1, 2 and 4 only
   • c)1, 3 and 4 only
   • d)2, 3 and 4 only

   Explanation: VLC uses visible light (375-780 nm), transmits data faster than Bluetooth and is free of electromagnetic interference, but it is a short-range technology, so statement 2 is wrong and the answer is 1, 3 and 4 only.

4. Q4.Information Technology

   With reference to 'Blockchain Technology', consider the following statements. Which of the statements given above is/are correct?

   • a)1 only
   • b)1 and 2 only
   • c)2 only
   • d)1 and 3

   Explanation: A blockchain is a decentralized public ledger and permissionless applications can be built on it, but it can store any kind of data, not only cryptocurrency, so statement 2 is wrong and the answer is 1 and 3.

5. Q5.Nanotechnology

   With reference to carbon nanotubes, consider the following statements. Which of the statements given above are correct?

   • a)1 and 2 only
   • b)2, 3 and 4 only
   • c)1, 3 and 4 only
   • d)1, 2, 3 and 4

   Explanation: Carbon nanotubes can carry drugs and antigens, be used in biochemical sensors and are biodegradable under certain conditions, but they cannot be made into artificial blood capillaries, so statement 2 is wrong and the answer is 1, 3 and 4 only.

6. Q6.Drone Technology

   Consider the following activities. At the present level of technology, which of the above activities can be successfully carried out by using drones?

   • a)1 and 2 only
   • b)2 and 3 only
   • c)1 and 3 only
   • d)1, 2 and 3

   Explanation: Drones are already used for crop spraying, inspecting volcanic craters and collecting whale-blow samples, so all three activities are feasible.

7. Q7.Space Technology

   'The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometres long, with lasers shining between the craft.' The experiment in question refers to

   • a)Voyager-2
   • b)New Horizons
   • c)LISA Pathfinder
   • d)Evolved LISA

   Explanation: The description of three spacecraft in a million-kilometre triangle using lasers matches the Evolved LISA (eLISA) mission to detect gravitational waves.

8. Q8.Biotechnology

   Consider the following statements about genetic technology. Which of the statements given above is/are correct?

   • a)1 only
   • b)2 and 3 only
   • c)2 only
   • d)1, 2 and 3

   Explanation: Germline editing of gamete-producing cells and embryonic genome editing are technically possible, and human iPS cells have been injected into pig embryos to create chimeras, so all three statements are correct.

9. Q9.Health

   What is the importance of using Pneumococcal Conjugate Vaccines in India?

   • a)1 only
   • b)1 and 2 only
   • c)3 only
   • d)1, 2 and 3

   Explanation: Pneumococcal conjugate vaccines protect against pneumonia, meningitis and sepsis and reduce reliance on antibiotics, but like all vaccines they can cause side effects and allergic reactions, so statement 3 is wrong and the answer is 1 and 2 only.

10. Q10.Cyber Security

    In India, the term 'Public Key Infrastructure' is used in the context of

    • a)Digital security infrastructure
    • b)Food security infrastructure
    • c)Health care and education infrastructure
    • d)Telecommunication and transportation infrastructure

    Explanation: Public Key Infrastructure (PKI) supports encryption and digital signatures and is part of digital security infrastructure.

11. Q11.Biology

    Which of the following statements are correct regarding the general difference between plant and animal cells?

    • a)1 and 2 only
    • b)2 and 3 only
    • c)1 and 3 only
    • d)1, 2 and 3

    Explanation: Plant cells have cellulose walls and a single large vacuole, so statements 1 and 3 are correct; both plant and animal cells have plasma membranes, so statement 2 is wrong, giving 1 and 3 only.

12. Q12.Nuclear Energy

    In India, why are some nuclear reactors kept under 'IAEA Safeguards' while others are not?

    • a)Some use uranium and others use thorium
    • b)Some use imported uranium and others use domestic supplies
    • c)Some are operated by foreign enterprises and others are operated by domestic enterprises
    • d)Some are State-owned and others are privately-owned

    Explanation: Under the India-IAEA arrangement, reactors using imported uranium are placed under IAEA safeguards, while those run on domestic fuel are not.