It is not always an easy thing to tell the difference between living, dead, and non-living things. Prior to the 1600's many people believed that nonliving things could spontaneously turn into living things. For example, it was believed that piles of straw could turn into mice. That is obviously not the case. There are some very general rules to follow when trying to decide if something is living, dead, or non-living. Listed here are the six rules used by scientists:
- Living things are made of cells.
- Living things obtain and use energy.
- Living things grow and develop.
- Living things reproduce.
- Living things respond to their environment.
- Living things adapt to their environment.
If something follows one or just a few of the rules listed above, it does not necessarily mean that it is living. To be considered alive, an object must exhibit all of the characteristics of living things. Sugar crystals growing on the bottom of a syrup container is a good example of a nonliving object that displays at least one criteria for living organisms.
Can you think of some other examples of nonliving objects displaying living characteristics?
