CLINICAL MEDICINE

Detailed explanation-1: -After gaining entry into the body, a virus makes physical contact with and crosses the plasma membrane of a target cell. Inside, it releases and replicates its genome while facilitating the manufacture of its proteins by host ribosomes. How this is carried out depends upon the type of viral nucleic acid.

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.

Detailed explanation-3: -Most viruses reproduce through a process called lytic infection. During lytic infection, a virus enters the host cell, makes a copy of itself, and causes the cell to burst, or lyse.

Detailed explanation-4: -They do not possess ribosomes and cannot independently form proteins from molecules of messenger RNA. Because of these limitations, viruses can replicate only within a living host cell.

Detailed explanation-5: -Indeed, viruses have the remarkable ability to spread from one host to another host, hosts that belong to the three cellular domains of life-Archaea, Bacteria, and Eukarya. This constitutes their host range.