what is the function of a virion?
A complete viral particle, consisting of RNA or DNA surrounded by a protein shell and constituting the infective form of a virus. virion. A complete viral particle, consisting of RNA or DNA surrounded by a protein shell and constituting the infective form of a virus. The shell, called a capsid, protects the interior core that includes the genome and other proteins. After the virion binds to the surface of a specific host cell, its DNA or RNA is injected into the host cell and viral replication occurs with eventual spread of the infection to other host cells.