Question

What is the difference between viroids and prions?

Answer 1

Subviral agents:

1. These are pathogenic structures or non-cellular organisms whose size is smaller than viruses.
2. Structure wise also they may lack one of the essential features of a virus.
3. It is divided into 4 groups namely- satellite viruses, viroids, Virusoids, and prions.

Viroids: These are subviral particles that contain RNA as the genetic material.

Prion: These subviral particles are composed of proteins exclusively without genetic material.

Viroids	Prions
Viroids are small, circular, single-stranded RNA molecules that are considered the smallest known pathogens.	These are proteinaceous infectious particles. They have a distinct extracellular form, which is entirely a protein.
These cause a number of important plant diseases.	These do not cause disease in plants but are able to reproduce in mammalian cells.
The viriod molecules enter the plant through a wound or an insect or other mechanical damage. Later, it gets replicated in the host cell nucleus by RNA polymerases.	The prion particle does not contain any nucleic acid. However, it is infectious and known to cause several neurodegenerative diseases found in mammals.