Which of the following is a characteristic only found in some viruses?

• A. A protein capsid surrounding the genetic material
• B. The presence of either DNA or RNA as genetic material
• C. An envelope derived from the host cell membrane
• D. Ability to infect living cells

Answer: (C)

Verified step by step guidance

1. Understand the basic structure of viruses: all viruses have genetic material (either DNA or RNA) and a protein capsid that surrounds this genetic material.
2. Recognize that the ability to infect living cells is a universal characteristic of all viruses, as they require host cells to replicate.
3. Identify that the presence of either DNA or RNA as genetic material is a fundamental trait common to all viruses, but not both simultaneously.
4. Focus on the viral envelope: some viruses have an outer lipid envelope derived from the host cell membrane, while others do not. This envelope is not found in all viruses.
5. Conclude that the characteristic unique to only some viruses is the presence of an envelope derived from the host cell membrane.