Viroids are single-stranded, covalently closed circular RNA molecules. As a distinct class of pathogens, they are clearly distinguished from viruses by their small size (∼250–400 nt), do not encode any protein and lack a capsid.

Do Viroids have DNA or RNA?

Viroids are the smallest pathogenic agents yet described. They are single-stranded circular RNA molecules which vary in length from 246 to 463 nucleotides and are found only in plants.

Is RNA absent in Viroids?

(a) Virus contains DNA or RNA as genetic material and a protein coat, whereas viroids. have no protein coat, but only RNA as their nucleic acid.