NEET BIOLOGY

Detailed explanation-1: -First, viroids are the only infectious agents that lack protein components such as capsids. In general, the role of the viral capsid is the protection of the viral genome from degradation. Second, the viroid has a circular RNA genome, unlike most RNA viruses.

Detailed explanation-2: -A virion is an entire virus particle consisting of an outer protein shell called a capsid and an inner core of nucleic acid (either ribonucleic or deoxyribonucleic acid-RNA or DNA). The core confers infectivity, and the capsid provides specificity to the virus.

Detailed explanation-3: -Each virus possesses a protein capsid to protect its nucleic acid genome from the harsh environment. Virus capsids predominantly come in two shapes: helical and icosahedral.

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: -Viruses and viroids are disease-causing organisms. The difference between virion (virus) and viroid is that viroid is a smaller form of a virus with RNA nucleic acid. In contrast, a virus can have either DNA or RNA.