Which of the following is a major difference between viruses and living things?

A virus is acellular and is not necessarily considered a living organism. A bacterium has one cell and is considered a living organism. The next difference is in size. Bacteria can be 1000 nanometers long, whereas viruses can be 20-400 nanometers long. Viruses can infect bacteria as well.

The crucial difference between viruses and living things are that most living things can reproduce on one's own, however viruses must infect living cells in order to reproduce.

Explanation:

Viruses are not made out of cells, they can't keep themselves in a stable state. They don't grow or even make their own energy. Even though they unquestionably replicate and adapt to their environment, viruses are more automaton-like than real living life forms.