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Shapes
a. Helical viruses consist of nucleic acid surrounded by a hollow protein cylinder or capsid and possessing a helical structure.
b. Polyhedral viruses consist of nucleic acid surrounded by a polyhedral (many-sided) shell or capsid, usually in the form of an icosahedron .
c. Enveloped viruses consist of nucleic acid surrounded by either a helical or polyhedral core and covered by an envelope.
d. Binal (complex) viruses have neither helical nor polyhedral forms, are pleomorphic (irregular shaped), or have complex structures .
What is a shape a virus may present in?