Bacteria, Viruses, and Protists

Virus Basics

What is the structure of a virus?

Viruses consist of strands of the genetic material nucleic acid—either as RNA or DNA, but not both—surrounded by a protein coat called a capsid. The capsid protects the genome (collection of genes); it is often subdivided into individual protein particles called capsomeres—features that create the shape of the virus. The capsid protein coat of a virus can come in three main shapes: Helical, resembling a wound spring (such as the tobacco mosaic virus); isosahedral, a multifaceted virus (such as the herpes simplex); and complex, as the name implies, can be combination of shapes (such as T-4 bacteriophage).


This is a web preview of the "The Handy Biology Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App