Acquisition of new qualities by living organisms in the process of life.

The life of any organism is possible due to the fact that it breathes, feeds, and harmful substances are removed from it. Nutrients provide the body with material and, in conjunction with respiration, energy for growth. During growth, not only an increase in size occurs, but also qualitative changes inside the body. The acquisition of new qualities by living organisms in the process of life is called development. Having reached a certain stage of development, a living organism becomes capable of reproduction.