How do viruses replicate?

Viruses replicate by taking over the host cell's reproductive machinery. This process begins when a virus attaches to a susceptible host cell and injects its genetic material — either DNA or RNA — into the cell. Once inside, the virus hijacks the host's cellular processes to produce viral components, such as proteins and nucleic acids. These components are then assembled into new virus particles, which eventually exit the host cell to infect other cells.

This method of replication is essential for viruses because they lack the necessary cellular structures and metabolism to reproduce independently. Unlike living organisms, viruses cannot divide on their own; they must exploit the host cell's biology to propagate. This reliance on a host cell is what classifies viruses as obligate intracellular parasites, as they completely depend on a living cell for their lifecycle.