Question

What do we call a proteinaceous particle that can replicate inside a host cell and cause disease?

• A. Virion
• B. Prion
• C. Viroid
• D. Phage

Answer 1

Answer: (B)

Prions are proteinaceous infectious particles. These are misfolded (abnormally folded) protein molecules, which on entering a host organism induce existing and properly folded proteins to convert into the misfolded prion.
All known prion diseases, collectively called transmissible spongiform encephalopathies $(TSEs)$ are untreatable and fatal. Virion is inert virus. It can be crystallised and stored indefinitely. Viroids are the smallest, self-replicating, infectious $RNA$ particles which are devoid of protein coat. The term phage refers to a virus that is parasitic over lower organisms e.g. bacteriophages are the viruses that infect bacteria, cyanophages are the viruses that affect cyanobacteria, etc.