NEET BIOLOGY

Detailed explanation-1: -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-2: -The capsid, which is formed in a stepwise manner, has no gaps in between and fully encompasses the genome. Poliovirus, herpesvirus, papillomavirus, rhinovirus, and adenovirus are some examples of viruses with an icosahedral capsid.

Detailed explanation-3: -A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes.

Detailed explanation-4: -A virus without a capsid is called viroid. Viroids have only nucleic acid in their structure, they have not any protein coat. They have single-stranded RNA in their genome. Bacteria have prokaryotic cell organization.

Detailed explanation-5: -There are all sorts of virus shapes and sizes. However, all virus particles have a protein coat that surrounds and protects a nucleic acid genome. This protein coat is called a capsid, and the instructions for making the protein subunits of the capsid are encoded in the nucleic acid genome of the virus.