Question

Prions are the -

• A. infections proteinaceous agents
• B. DNA without protein coat
• C. RNA without protein coat
• D. Protozoans

Hint:

The name "prion," coined by Stanley Prusiner, is derived from "{pr}oteinaceous {i}nfectious particle." The name itself is the definition.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The question asks for the definition of a prion, which is a type of acellular infectious agent.
Step 2: Detailed Explanation:
Prions: These are unique infectious agents composed solely of misfolded protein. They contain no genetic material (DNA or RNA). A prion protein can induce normally folded proteins of the same type to also misfold, leading to aggregation and causing fatal neurodegenerative diseases like Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy (mad cow disease) in cattle. Thus, they are infectious proteinaceous agents.
DNA without protein coat: No known infectious agent fits this description.
RNA without protein coat: This is the definition of a viroid, an infectious agent that affects plants.
Protozoans: These are single-celled eukaryotic organisms like Amoeba or Plasmodium. They are cellular, not acellular agents.
Step 3: Final Answer:
Prions are infectious proteinaceous agents.