Question

Difference between virus and viroid is

• A. absence of protein coat in viroid but present in virus
• B. presence of low molecular weight $RNA$ in virus but absent in viroid
• C. both (a) and (b)
• D. none of the above

Answer 1

The Correct Option is A

Viroids are smallest known agent of infectious diseases. They lack capsid as well as proteins (that are present in virus) and consist of only single stranded $RNA$. The $RNA$ of the viroid is of low molecular weight.

Answer 2

The differences between viruses and viroids are

 

Features	Virus	Viroid
Nucleic acid	The genetic material is either DNA or RNA. DNA is double-stranded while RNA can be either single-stranded or double-stranded.	Their genetic material is composed of single-stranded low molecular-weight RNA.
Capsid	A protein coat, or capsid, is present.	The protein coat, or capsid, is absent.
Protein	It manufactures proteins and enters the host cell.	Viroid RNA does not code for any proteins.
Host	They infect bacteria, plants, and animals.	They infect only plants.

 
 

 
 
 
 
 
 

 

As a result, the correct answer is "absence of a protein coat in the viroid but the presence of a protein coat in the virus.
 

Answer 3

The distinction between a virus and a viroid is that viruses have DNA or RNA as their genetic material as well as a protein coat, whereas viroids have no protein coat and only RNA as their nucleic acid.