EXPLANATION OF PICTURE:
The smallpox virus consists of genetic material (one molecule of double stranded DNA) contained in a core (red). In this illustration, the virus is tilted, showing the rounded
biconcave brick shape of the core, in whose depressions nestle the "lateral
bodies" (purple). The function of the lateral bodies is unknown. The virus includes several layers of host cell membrane (green & blue) added at various points in its
life cycle. The poxviruses are the most complicated type of animal virus.