Life cycle of a virus. Illustration of the stages in the life cycle of a virus (red). Each virus particle (virion) has a protein coat (red dots) and contains genetic material (DNA, deoxyribonucleic acid, yellow). The virion enters the host cell (blue) and releases its DNA (upper centre). The cell's biochemical machinery is used to make new protein coating (centre left) by DNA transcription and RNA (ribonucleic acid) translation, plus making new DNA by replication (centre right). The new DNA and proteins come together (lower centre) to exit the cell and produce new virus particles that spread the infection. For this artwork with labels, see C023/8888.