Why virus are called obligatory parasites?

Answer 1

They are obligate in the sense that they cannot replicate outside of a host cell.

To make a copy of itself, a virus must first enter a cell (intracellular), hijack the machinations of said cell (parasitic behavior) and then copy itself.

Answer 2

Virus becomes parasite and plays its role after it gets inside a living thing ,there life is like made to get inside the livingthing and play it's role therfore their getting of parasite only after getting inside a living thing is said as an obligation for them to be a parasite when they are not inside livingthing i.e,there main life phase in which they are out of the livingthing where nature gives virus a beggining form which is out of living thing hence, it sustains in obligation to be a parasite so,virus are obligatory parasite.

Answer 3

Viruses are called obligatory parasites because they depend on living host cells to replicate and multiply. They lack the cellular machinery needed for reproduction and metabolic activities, so they must invade host cells and hijack their machinery to reproduce. Without a host cell, viruses are unable to replicate and survive.

Answer 4

Because they absolutely require living host cells in order to multiply