AP BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -Viroids are infectious agents that consist only of naked RNA without any protective layer such as a protein coat.

Detailed explanation-3: -Viroids cause a variety of plant diseases, including potato spindle tuber disease, apple fruit crinkle, chrysanthemum stunt, and others. Thus, Viroids do not have DNA, they have RNA as their genetic material.

Detailed explanation-4: -Viroids contain only RNA. These are known to be smaller in size and infect only the plants. These are among the smallest known agents causing infectious disease. Viroids are species of nucleic acid with relatively low molecular weight and a unique structure.

Detailed explanation-5: -Note: viroids are the smallest pathogens known to humans. They only infect the plant and cause diseases in them. They are not found to be infectious in humans or animals. They have single-stranded RNA and have an absence of the protein coat on them.