What set of characteristics do living organisms such as birds, trees, and bacteria have that distinguish them from nonliving things? Although viruses share many traits with other living organisms, some people do not consider them to be alive. For this question you may disregard viruses

The 7 (sometimes 8) characteristics of life are:

1. living things are composed of cells

2. living things have different levels of organization

3. living things metabolize (i. e. use energy)

4. living things respond to their environment

5. living things grow

6. living things reproduce

7. living things adapt to their environment

(some sources include) 8. living things have genetic material

Viruses do not metabolize, they do not grow, they do not adapt to their environment, and they cannot reproduce independently; viruses require host cells to reproduce and perform the other functions that give them the appearance of aliveness.