
Imagine a submicroscopic packet of proteins arranged symmetrically to enclose an inner genome -- and you have a virus. Viruses are so miniscule in size that most require electron microscopy to see them clearly, and more than 3,000 polio virus particles could fit end-to-end in a straight line across the period at the end of this sentence. Now, that’s small! Yet, many viruses wreak havoc on vastly larger and more complex organisms.







