Caption

Virus replication, illustration. Viruses consist of a genome and sometimes a few enzymes stored in a capsule (called a capsid) made of protein, and sometimes covered with a lipid layer (an 'envelope'). The genome is shown here in the form of part of the helix of the genetic molecule DNA (deoxyribonucleic acid, centre). Viruses cannot reproduce on their own, and instead propagate by subjugating a host cell to produce copies of themselves. They sabotage the host cell in the process and produce their next generation. This artwork shows new copies of the virus budding off the host cells.