Q. 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?
(a) Only one
(b) Only two
(c) All the three
(d) None
Correct answer: (d) None
UPSC Prelims 2025 GS Paper's Solution
Explanation :
Statement I is false – Viruses are abundant in ocean waters, especially bacteriophages (viruses that infect bacteria). Marine viruses are known to be extremely numerous and play a significant role in marine ecosystems.
Statement II is false – bacteriophages are viruses that specifically infect bacteria.
Statement III is false – many viruses (e.g. herpesviruses, retroviruses) encode proteins or RNAs that reprogram host‐cell transcription.
