IMMUNOLOGY

Detailed explanation-1: -Viruses survive outside our bodies because of how they are built. Specifically, they are pieces of genetic material (RNA or DNA) contained in a special coating of proteins called capsids. Viruses cannot replicate unless absorbed by cells in our body.

Detailed explanation-2: -Viruses rely on the cells of other organisms to survive and reproduce, because they can’t capture or store energy themselves. In other words they cannot function outside a host organism, which is why they are often regarded as non-living.

Detailed explanation-3: -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-4: -Viruses are a non-living collection of molecules that need a host to survive. Viruses need to enter a living cell (such as a human cell) to be able to reproduce, and once inside they take over all of the cellular machinery and force the cell to make new virus.