Which of the following statements correctly describes prions, but not viroids?

• A. They infect plants and disrupt normal cellular processes.
• B. They are infectious proteins that lack nucleic acids.
• C. They contain both DNA and RNA genomes.
• D. They consist of a short, circular RNA molecule without a protein coat.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definitions of prions and viroids. Prions are infectious agents composed solely of protein, without any nucleic acids (DNA or RNA). Viroids, on the other hand, are small infectious RNA molecules that lack a protein coat.
2. Step 2: Analyze the given statements one by one to see which applies to prions but not viroids.
3. Step 3: The statement 'They infect plants and disrupt normal cellular processes' applies to viroids, as viroids typically infect plants, so this does not describe prions.
4. Step 4: The statement 'They are infectious proteins that lack nucleic acids' correctly describes prions, since prions are misfolded proteins that cause disease without containing DNA or RNA, unlike viroids.
5. Step 5: The other statements either mention nucleic acids (DNA and RNA genomes) or describe viroids (short, circular RNA without a protein coat), so they do not correctly describe prions.