What is the smallest structural and functional unit of life?

The smallest structural and functional unit of life is the cell. The cell is the fundamental unit of life and is capable of performing all the necessary functions of an organism. It is the basic building block of all living things, and all organisms are composed of one or more cells. Cells are responsible for the maintenance and growth of an organism and are the site of all metabolic processes.
Cells are the basic unit of life, composed of a cell membrane, cytoplasm, and genetic material. Groups of similar cells form tissues, which work together to perform specific functions. Organs are made up of different tissues and work together to perform specific functions. Organisms are single-living individuals made up of various organ systems.