NEET BIOLOGY

Detailed explanation-1: -Viroids are infectious agents that consist only of naked RNA without any protective layer such as a protein coat. Viroids infect plants (but no other forms of life) and are replicated at the expense of the host cell. Viroid genomes are small single-stranded circles of RNA that are only 250–400 bases long.

Detailed explanation-2: -virion: an individual virus particle outside a host cell. viral envelope: a lipid bilayer that envelops some viruses.

Detailed explanation-3: -What are Viroids? Viroids are infectious pathogens that affect only plants, therefore are also called plant pathogens. Structurally, viroids are smaller than viruses and possess circular strands of ribonucleic acids (RNAs) with no protein coating.

Detailed explanation-4: -The virion, that is the complete infectious virus particle, includes a genome comprising one or a few molecules of either DNA or RNA, surrounded by a morphologically defined protein coat, the capsid; the capsid and the enclosed nucleic acid together constitute the nucleocapsid.

Detailed explanation-5: -Viroids are small and infectious RNA particles that do not code for proteins. They do not possess the protein coat. They are known to infect the plants.