Correct Option (D)
Explanation
All three statements are incorrect.
- Statement 1 is incorrect: Viruses are highly abundant in ocean waters. Marine viruses, especially bacteriophages, are the most numerous biological entities in the sea. They play crucial roles in marine microbial ecology, nutrient cycles, and carbon flow. Many viruses can survive in seawater for extended periods, with their viability influenced by factors such as salinity, temperature, and UV exposure.
- Statement 2 is incorrect: Viruses can infect bacteria. These viruses are specifically called bacteriophages. They attach to bacterial cells, inject their genetic material, and replicate using the bacterial host's cellular machinery. Bacteriophages are prevalent in all environments where bacteria exist.
- Statement 3 is incorrect: Viruses frequently alter the host cell’s transcriptional activity. This manipulation is essential for viral replication and to evade host immune responses. Viruses can upregulate genes necessary for viral protein synthesis and suppress host gene expression. Examples include the influenza virus hijacking host RNA polymerase and HIV modifying host transcription factors to facilitate their life cycle.
Since all three statements are factually incorrect, the option "None" is the correct answer.
Incorrect Options
Options 1, 2, and 3 are incorrect because they suggest that at least one or more of the given statements are correct. However, based on virological principles, all three statements provided are factually inaccurate.