Which of the following organisms are not susceptible to infection by viruses?

• A. Animals
• B. Prions
• C. Bacteria
• D. Plants

Answer: (B)

Verified step by step guidance

1. Step 1: Understand what susceptibility to viral infection means. An organism susceptible to viral infection can be invaded and have its cellular machinery used by viruses to replicate.
2. Step 2: Review the types of organisms listed: Animals, Bacteria, Plants, and Prions. Animals, bacteria, and plants all have cellular structures that viruses can infect.
3. Step 3: Recall that prions are infectious proteins, not living cells, and they do not have nucleic acids or cellular machinery for viruses to hijack.
4. Step 4: Conclude that since viruses require living cells to replicate, prions cannot be infected by viruses because they are not cells and lack the necessary components for viral replication.
5. Step 5: Therefore, prions are the organisms (or infectious agents) among the options that are not susceptible to viral infection.