AP BIOLOGY

Detailed explanation-1: -In the simpler viruses the virion consists of a single molecule of nucleic acid surrounded by a protein coat, the capsid; the capsid and its enclosed nucleic acid together constitute the nucleocapsid. In some of the more complex viruses the capsid surrounds a protein core (Fig.

Detailed explanation-2: -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.

Detailed explanation-3: -The outer protein coat of a virus is known as the capsid. It consists of several oligomeric structural subunits made of a protein called protomers which cover the nucleic acid which is present in the virus and protects it when virus inserts itself into the host.

Detailed explanation-4: -Definition. A virus is an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat.

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.