生物英语系列小短文（四）Characteristics of Living things_生物论文

It is not always an easy thing to tell thedifference between living, dead, and non-living things. Prior to the 1600‘smany people believed that nonliving things could spontaneously turn into livingthings. 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 followwhen trying to decide if something is living, dead, or non-living. Listed hereare the six rules used by scientists:

1.Living things are made of cells.

2.Living things obtain and use energy.

3.Living things grow and develop.

4.Living things reproduce.

5.Living things respond to their environment.

6.Living things adapt to their environment.

If something follows one or just a few ofthe rules listed above, it does not necessarily mean that it is living. To beconsidered alive, an object must exhibit all of the characteristics of livingthings. Sugar crystals growing on the bottom of a syrup container is a goodexample of a nonliving object that displays at least one criteria for livingorganisms.

Can you think of some other examples ofnonliving objects displaying living characteristics?