Question

Write one difference between viruses and viroids.

Answer 1

Viruses contain both nucleic acids (DNA or RNA) and a protein coat. Viruses cause infection by inserting their genetic material in a host cell. The host cell then replicates and reads the genetic material, making new viruses that eventually burst out of the cell and leave to infect more. The reason viruses cause disease is that the infected cells cannot carry out the normal functions necessary because its machinery is being used by the virus, and eventually the cell dies.

Viroids have no protein coat, but are only the nucleic acid (RNA). Because of this, they are often carried around inside viruses. For example, Hepatitis D is a viroid that is carried in the capsid of the Hepatitis B virus.