In an introduction to viruses, which statement correctly describes the types of nucleic acids found in viral genomes?

• A. Viral genomes are always double-stranded DNA.
• B. Viruses may contain either DNA or RNA as their genetic material, but not both in the same virion.
• C. Viral genomes are always single-stranded RNA.
• D. All viruses contain both DNA and RNA to ensure replication in diverse hosts.

Answer: (B)

Verified step by step guidance

1. Understand that viral genomes can vary widely in their nucleic acid composition, which is a key characteristic in virology.
2. Recall that viruses are unique in that their genetic material can be either DNA or RNA, but not both simultaneously within the same viral particle (virion).
3. Recognize that viral genomes can be single-stranded or double-stranded, and can be composed of either DNA or RNA, depending on the virus type.
4. Eliminate options that state viral genomes are always double-stranded DNA or always single-stranded RNA, as these are too restrictive and do not cover the diversity of viruses.
5. Conclude that the correct description is that viruses may contain either DNA or RNA as their genetic material, but not both in the same virion, reflecting the diversity and exclusivity of viral genome types.