Difference Between Virus and Viroids
In this article we will discuss about Differences Between Viroids and Prions.
Virus
Virus is a microscopic, infectious particle that can reproduce or replicate within the living cell of an organism or host. Viruses can not reproduce without a host cell. They infect almost all living forms such as animals, plants, and bacteria.
In 1898, a Dutch scientist, Martinus Beijerinck discovered the world’s first virus which was the tobacco mosaic virus. He conducted an experiment to show that there is another infectious particle that is smaller than bacteria and responsible for the infection in tobacco plants.
Viroid
In 1971, a plant pathologist named Theodor Otto Diener first discovered the Viroids. He found an acellular particle when he was working in an Agriculture Research Service and named this particle as viroid, meaning “virus-like.” At present-33 species of viroid have been identified.
Viroids are known as the smallest infectious pathogens which are made up solely of a short strand of circular, single-stranded self-replicating RNA that has no protein coating.
Difference Between Virus and Viroids
| Topic | Virus | Viroids |
| Definition | A virus refers to a small infectious agent that replicates only inside the living cells of other organisms | viroids refer to the infectious particles smaller than any of the known viruses, serving as an agent of certain plant diseases. |
| Significance | virus is a nucleoprotein particle | viroids are RNA particles. |
| Size | a virus is a larger particle as compared to Viroids | viroids are smaller than viruses |
| Type of Nucleic Acid | viruses contain either DNA or RNA | viroids contain a short strand of circular, single-stranded RNA as their nucleic acid. |
| Protein Coat | virus contains a protein coat surrounding its nucleic acid | viroids do not contain a protein coat. |
| Type of Host | viruses can infect different forms of hosts including animal, plant or bacterial cells | viroids infect only plant cells. |
| Production of Proteins during Replication | The virus produces proteins during their replication | viroids do not produce proteins during replication. |
| Examples | EBV, adenoviruses, hepatitis B, influenza A, etc. | potato spindle tuber viroid, Avsunviroidae, etc. |
