Select the true statement about viral infection of a host cell.

• A. Viruses must enter a host cell to replicate their genetic material.
• B. Viruses contain both DNA and RNA in their genome.
• C. Viral infection always results in immediate cell death.
• D. Viruses can reproduce independently without a host cell.

Answer: (A)

Verified step by step guidance

1. Understand the nature of viruses: Viruses are obligate intracellular parasites, meaning they require a host cell to carry out their replication process.
2. Analyze the statement 'Viruses must enter a host cell to replicate their genetic material': This is true because viruses lack the cellular machinery needed for replication and must hijack the host's machinery.
3. Consider the statement 'Viruses contain both DNA and RNA in their genome': This is false because viruses have either DNA or RNA as their genetic material, but never both simultaneously.
4. Evaluate the statement 'Viral infection always results in immediate cell death': This is incorrect since some viral infections can be latent or chronic without causing immediate death of the host cell.
5. Review the statement 'Viruses can reproduce independently without a host cell': This is false because viruses cannot reproduce on their own; they depend entirely on a host cell for replication.