Which of the following is a characteristic of a virus?

• A. Composed solely of proteins without any nucleic acids
• B. Contains either DNA or RNA as its genetic material
• C. Can replicate independently outside a host cell
• D. Is capable of metabolic activity on its own

Answer: (B)

Verified step by step guidance

1. Understand the basic structure of viruses: Viruses are composed of genetic material (either DNA or RNA) enclosed within a protein coat called a capsid.
2. Recall that viruses lack cellular structures and cannot carry out metabolic processes independently, meaning they require a host cell to replicate.
3. Recognize that viruses do not contain both DNA and RNA simultaneously; they have either one or the other as their genetic material.
4. Eliminate options that describe characteristics not true for viruses, such as being composed solely of proteins without nucleic acids, or being capable of independent replication or metabolism.
5. Conclude that the defining characteristic of viruses is that they contain either DNA or RNA as their genetic material, which is essential for their ability to infect host cells and replicate.