Viruses can survive outside a host but they require host cells to reproduce. There are two ways lifecycle pathways that viruses can take:
1. As soon as the virus penetrates the host cell, it synthesises proteins that break down the host’s DNA, so that it can take over the cell’s machinery.
2. It uses the cell’s machinery to synthesise proteins for the production of new virus particles
3. This causes the viruses to burst out of the host cell, killing the cell in the process, which is called lysis.
4. The process is then repeated with nearby cells
1. The virus attaches to the cell surface of the host cell, then penetrates through the surface.
2. It infects the host cell by injecting its DNA into the host cell’s cytoplasm.
3. The host cell replicates, and the viral DNA is also copied in this process because all DNA is made from the same base molecules.
4. Under the right conditions, viral DNA will undergo induction. At this point, the lysogenic cycle transitions to the lytic cycle.