EVERYDAY SCIENCE

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: -A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres.

Detailed explanation-3: -Virus Core Structure Small virions are simple nucleocapsids containing 1 to 2 protein species. The larger viruses contain in a core the nucleic acid genome complexed with basic protein(s) and protected by a single-or double layered capsid (consisting of more than one species of protein) or by an envelope (Fig. 41-5).

Detailed explanation-4: -The diversity of nucleic acids found in viruses is startling. Viruses may contain: linear double-stranded (ds) DNAs; circular ds DNAs; linear or circular single-stranded (ss) DNAs; coding (’+ strand’) RNAs; RNAs (’− strand’) whose complements encode viral proteins; and dsRNAs.