EVERYDAY SCIENCE

Detailed explanation-1: -A virus is a tiny, infectious particle that can reproduce only by infecting a host cell. Viruses “commandeer” the host cell and use its resources to make more viruses, basically reprogramming it to become a virus factory. Because they can’t reproduce by themselves (without a host), viruses are not considered living.

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: -Viruses initially stick to cell membranes through interactions unrelated to fusion proteins. The virus surfs along the fluid surface of the cell and eventually the viral fusion proteins bind to receptor molecules on the cell membrane (4).

Detailed explanation-4: -In general terms, virus replication involves three broad stages which are present in all viruses: initiation of infection, replication and expression of the genome, and the release of mature virions from the infected cell.