What is a Virus?

Polyhedral Virus

consist of nucleic acid surrounded by a polyhedral shell or capsid, usually in the form of an icosahedron.

Helical Virus

consist of nucleic acid surrounded by a hollow protein cylinder or capsid and possessing a helical structure

Spherical Virus

consist of nucleic acid surrounded by either a helical or polyhedral core and covered by an envelope

Complex Virus

have neither helical nor polyhedral forms, are pleomorphic or irregular shaped, or have complex structures