Unlike nonliving things, living things grow and reproduce, sense and respond to changes in their environment, and assimilate nutrients. Living things also possess cells and DNA as their basic units of life, units that are lacking in nonliving things.
Living things die and, without reproduction, disappear. Reproduction takes place either sexually or asexually, the former by the combination of genes from two different parents and the latter by an organism splitting into two or more different organisms. The resulting organisms are more closely identical to the parent in asexual reproduction than in the case of sexually reproducing organisms. Many organisms also grow through an accumulation of new cells that they produce, a process that does not occur in nonliving entities.
Living things, unlike nonliving things, can also sense and respond to changes in their environments. These activities take place on both the cellular level and on the level of the organisms. Examples include many mammals' ability to see, hear and smell approaching danger and the ability to leave to safer locations. Nonliving entities, such as rocks, are passive and cannot respond to stimuli.
Living things require nutrition to preserve life and grow. Producers, such as plants, make food for themselves, whereas consumers take in food from the environment.