alive
There is not just one distinguishing feature that separates a living thing from a non-living thing. A cat moves but so does a car. A tree grows bigger, but so does a cloud. A cell has structure, but so does a crystal. Biologists define life by listing characteristics that living things share. Something that has all of the characteristics of life is considered to be alive. The duck decoy in Figure below may look like a duck, act like a duck in that it floats about, but it is not alive. The decoy cannot reproduce, respond to its environment, or breathe.