What is the difference between a living and a nonliving thing?

You would have no trouble deciding that a dog running down the street was alive; nor would you have any trouble deciding that a stone was nonliving. However, if you ask yourself whether a bean seed, an apple, or a potato is living or nonliving, you may have problems deciding on the answer. All these appear just as nonliving as a stone. Yet we know that all three can produce a living plant. Since it seems unlikely that a nonliving thing can produce a living plant, we can assume that the bean seed, apple, and potato are living. What, then, are the characteristics of living things?

     What is life?

1. Atom
2. Molecules
3.  Cells 
4. Organisms
5.  Communities
6.  Ecosystem
7.  The Biosphere

The building blocks—atoms—that make up all living things are the same ones that make up all nonliving things.

Atoms join as molecules. The unique properties of life emerge as certain kinds of molecules become organized into cells.

Higher levels of organization include multi celled organisms, populations, communities, ecosystems, and the biosphere.