What features of cells indicate that they are alive?

The main feature of living cells is metabolism and energy. This includes the processes of nutrition, excretion, respiration. Life is impossible without movement. This refers to movement at the level of the cell, for example, the circulation of fluid in the body.

However, inanimate organisms can also move, but they do this under the influence of only external forces. Living organisms move in order to find favorable conditions.

Throughout life, living cells grow and develop, however, these signs are not enough for an organism to be considered alive (clouds and crystals also grow). Most importantly, living organisms are able to react to the environment, showing irritability.

A distinctive feature of a living thing is self-regulation (the ability to maintain the constancy of the internal environment under the variability of external conditions). Under the influence of various reasons, living organisms can change their characteristics, showing variability, and also pass them on to future generations. This is the principle of heredity.

However, all this would not have mattered if living organisms were not capable of reproduction. It is this property of the living that is important for the survival of the species.