PATHOLOGY

Detailed explanation-1: -Viruses are obligate intracellular parasites. They enter host cells, they use host cell machineries to replicate their genome and synthesize their proteins, and they produce progeny virions that are released in the extracellular environment.

Detailed explanation-2: -Since viruses are intracellular parasites, they rely on their host cells for the energy, macromolecular synthesis machinery and the work benches for genome replication and particle assembly.