NEET Class neet Answered

(i) Virus: A virus is defined as a microscopic, non-cellular, infectious organism which is primarily composed of genetic material. Influenza is a disease caused by virus.

(ii) Viriod: Viroids are the smallest infectious pathogens composed solely of a short strand of circular, single-stranded RNA with no protein coating.

(iii) Virion: A virion is a complete functional virus that has the capacity to infect living tissue. It contains a protein coating called a capsid, which surrounds the core of the virus containing the nucleic acid.

(iv) Gemini virus: Gemini viruses are plant viruses which have single-stranded circular DNA genomes encoding genes that diverge in both directions from a virion strand origin of replication.

(v) Satellite virus: A satellite virus is a subviral agent composed of nucleic acid that depends on the co-infection of a host cell with a helper virus for its replication.

(vi) Prion: A prion is a small infectious particle with no nucleic acids, composed of abnormally folded protein that causes progressive neurodegenerative conditions.