In an introduction to viruses, which statement best describes the genetic material of a virus?

• A. A virus contains peptidoglycan as its genetic material.
• B. A virus contains only messenger RNA (mRNA) and no other nucleic acid.
• C. A virus always contains both DNA and RNA in its genome.
• D. A virus contains either DNA or RNA as its genome (single-stranded or double-stranded), depending on the virus.

Answer: (D)

Verified step by step guidance

1. Understand that viruses are unique infectious agents that carry genetic material to replicate within host cells.
2. Recall that the genetic material of viruses can be either DNA or RNA, but never both simultaneously in the same virus.
3. Recognize that viral genomes can be single-stranded or double-stranded, depending on the type of virus.
4. Note that peptidoglycan is a component of bacterial cell walls, not genetic material, so it cannot be the genetic material of a virus.
5. Conclude that the best description is that a virus contains either DNA or RNA as its genome, but not both, and this genetic material can vary in strand type.