NEET BIOLOGY

Detailed explanation-1: -1. Helical Capsid Structure. 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: -All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules. In its infective form, outside the cell, a virus particle is called a virion.

Detailed explanation-3: -Fundamentally, the viral coat protein functions as protection for the genetic material inside the virus, and as an aid to infecting the host cell with virus DNA. Essentially, the coat protein (CP) is a link between the genetic material and infecting the host.

Detailed explanation-4: -The capsid of the human enteric viruses serves some crucial functions: RNase protection, attachment to host cell receptors (as part of the entry process), and also interaction with the host cellular immune system (12).

Detailed explanation-5: -The main function of virus coat protein is formation of the capsid that protects the virus genome against degradation. However, besides the structural function, coat proteins have many additional important activities in the infection cycle of the virus and in the defense response of host plants to viral infection.