<prompt> Capsid of viral structure is-Extracellular infectious particleProtein coat around nucleic acidEnvelop around a virusNone of the above  <response>: Ans. is b i.e., Protein coat around nucleic acid Structure of viruso The extracellular infectious virus particle is called as the virion.o The virion consist of a nucleic acid surrounded by a protein coat, the capsid.o The capsid with the enclosed nucleic acid is known as the nucleocapsid.o Two kinds of symmetry are encountered in the capsid -a Icosahedral cubicalb Helicalo Virion may be enveloped or nonenveloped naked.o Envelope is lipoprotein in nature, lipid is derived from host cell, while protein is virus coded. 