If protein were the genetic principle and not nucleic acid, significant mutagenic effects would be detected at .

capsid proteins interlock with a receptor site on the host cell. the capsid protein and host cell receptor interlock like a puzzle piece. viruses vary in shape to attack the various types of receptors on cells. the shapes of viruses include polyhedral, helical, enveloped, and complex. once the virus attaches to the host cell, it invades the cell and hijacks the dna of the cell.