Which of the following is a characteristic shared by all viruses?

• A. They contain either DNA or RNA as their genetic material.
• B. They possess a cell wall.
• C. They are capable of independent metabolism.
• D. They reproduce by binary fission.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the nature of viruses. Viruses are unique infectious agents that differ significantly from cellular life forms such as bacteria and eukaryotes.
2. Step 2: Review the options given and analyze each characteristic in the context of viruses. For example, consider whether viruses have cell walls, can metabolize independently, or reproduce by binary fission.
3. Step 3: Recall that viruses contain genetic material, but unlike cells, they can have either DNA or RNA, never both simultaneously. This genetic material is essential for their replication inside host cells.
4. Step 4: Recognize that viruses lack cellular structures such as cell walls and do not carry out independent metabolism; they rely entirely on host cells for energy and replication.
5. Step 5: Conclude that the only characteristic shared by all viruses is that they contain either DNA or RNA as their genetic material, which is fundamental to their identity and function.