What is the difference between a virus and a viroid?
Question
The other day I read about viroids and realized I had always lumped them together with viruses. Turns out, viroids are even simpler — just a naked RNA strand without any protein shell. This answer clears up all the key differences between viruses and viroids in a way that actually makes sense if you’re curious about how infections work.
Answer ( 1 )
Structure and Composition
Size and Complexity
Genetic Material
Host Range
Replication Mechanism
Pathogenic Mechanism
Examples
Diseases
Evolutionary Significance
In summary, while both viruses and viroids are infectious agents that depend on host cells for replication, viroids represent a much simpler form of infectious entity, consisting solely of a small RNA molecule without any protein components. Their discovery in 1971 by Theodor Diener expanded our understanding of the minimal requirements for an infectious agent and challenged the conventional boundaries of what constitutes “life.”
Source:
Flores, R., et al. (2014). Viroids and Viroid-Host Interactions. Annual Review of Phytopathology.
Diener, T.O. (1971). Potato spindle tuber “virus”: A plant virus with properties of a free nucleic acid. Science.