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UPSC Prelims 2025 GS Paper 1, question 49

Topic: Science and technology

Q49

Consider the following statements :

I. No virus can survive in ocean waters.

II. No virus can infect bacteria.

III. No virus can change the cellular transcriptional activity in host cells.

How many of the statements given above are correct?

  1. (a) Only one
  2. (b) Only two
  3. (c) All the three
  4. (d) NoneCorrect answer

Solution.

Answer: (d) None

  1. Statement I is incorrect: marine viruses (especially bacteriophages and cyanophages) are the most abundant biological entities in ocean waters, numbering around 10710^7 per millilitre of surface seawater.
  2. Statement II is incorrect: bacteriophages are viruses that specifically infect and replicate within bacteria.
  3. Statement III is incorrect: viruses routinely hijack and reprogram the cellular transcriptional and translational machinery of their host cells to express viral genes.