Introduction to viruses

Virions of some of the most common human viruses with their relative size. The nucleic acids are not to scale.
Life-cycle of a typical virus (left to right); following infection of a cell by a single virus, hundreds of offspring are released.
Two rotavirus particles: the one on the right is coated with antibodies which stop its attaching to cells and infecting them
The structure of DNA showing the position of the nucleosides and the phosphorus atoms that form the "backbone" of the molecule