Life and living things in the strict sense of the world's rich mainly of dead matter beyond the fact that they are able to reproduce (in a development that takes up more than mere copies) - that they organize themselves, that they have a metabolism. They form a closed system to the outside. [1] A system as such not yet mounts the stage of life, as well as inanimate combinations of individual units appear to be higher on several levels. [2]. If you want to reduce life to a single word, then it is that of inheritance. [3]