Why are bacteria considered alive but viruses are not?



User Avatar
Wiki User

Viruses have no self metabolism nor ability to reproduce autonomously, but bacteria can reproduce, grow and metabolize without the help of another cell.

An easy way to think about it is this: If all life in the Universe were to die, but bacteria were left in tact (alive), they would survive and continue to live and reproduce. If bacteria were wiped out as well as all other life, but viruses were unaffected (left in tact), they would all disintegrate/decay (fall apart) fairly quickly and there is no conceivable way they could reproduce.

This is because the virus isn't alive, it is just a collection of molecules that living things will "copy" (reproduce) if they come into contact with them, due to the particular interactions the living cell has with those viral molecules.