Question

How are viroids different from viruses?

Answer 1

Viroids are the smallest known agent of infectious diseases that contain small single-stranded RNA molecule. They lack capsid and have no proteins associated with them. Viroids infect only plants. Whereas, viruses have genetic material surrounded by a protective coat of protein or lipoprotein. The genetic material of viruses are of 4 types – double-stranded DNA, double-stranded RNA, single-stranded DNA, single-stranded RNA. They infect both plants and animals.

Answer 2

	Virus	Viroid
1.	It is made up of nucleoproteins.	It is made of RNA (ribonucleic acid).
2.	It may contain nucleic acids such as DNA and RNA.	Only DNA is found in it.
3.	A protein shell is found.	The protein shell is absent.
4.	Its size is large.	Its size is small.
5.	Viruses can infect all living organisms.	These infect only plants.