UPSC Prelims 2021 · GS Paper I

Science questions from UPSC 2021

Review every Science question in the 2021 paper with its answer and study explanation, then launch the same set under timed exam conditions.

Topic distribution

Physics · 2Biology · 1Biology & Virology · 1Biotechnology · 1Biotechnology & Human Health · 1Biotechnology & Vaccines · 1Chemistry & Properties of Water · 1Microbiology · 1Physics & Astronomy · 1

All 2021 Science questions

Open any question for the full options, answer, explanation, and syllabus metadata.

How answers are prepared
  1. Question 1 · Physics

    With reference to street-lighting, how do sodium lamps differ from LED lamps? 1. Sodium lamps produce light in 360 degrees but it is not so in the case of LED lamps. 2. As street-lights, sod...

  2. Question 2 · Microbiology

    Consider the following : 1. Bacteria 2. Fungi 3. Virus Which of the above can be cultured in artificial/synthetic medium?

  3. Question 3 · Biotechnology & Vaccines

    With reference to recent developments regarding 'Recombinant Vector Vaccines', consider the following statements : 1. Genetic engineering is applied in the development of these vaccines. 2....

  4. Question 4 · Physics

    In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following? 1. Area of the hole in the lid 2. Temperature of the flame 3. Weight of the lid...

  5. Question 5 · Biotechnology & Human Health

    In the context of hereditary diseases, consider the following statements : 1. Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy eit...

  6. Question 6 · Chemistry & Properties of Water

    Water can dissolve more substances than any other liquid because

  7. Question 7 · Biotechnology

    Bollgard I and Bollgard II technologies are mentioned in the context of

  8. Question 8 · Biology & Virology

    Consider the following statements : 1. Adenoviruses have single-stranded DNA genomes whereas retroviruses have double-stranded DNA genomes. 2. Common cold is sometime caused by an adenovirus...

  9. Question 9 · Physics & Astronomy

    Which one of the following is a reason why astronomical distances are measured in light-years?

  10. Question 10 · Biology

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