The cell is called the structural and functional unit of life because it’s the smallest, self-contained unit capable of performing all the life processes necessary for an organism to function. All living things are composed of cells, and the various life functions of an organism are carried out by the combined activities of its cells.
Here’s a more detailed explanation:
Structural Unit:
All living organisms, from single-celled bacteria to complex multicellular animals like humans, are fundamentally made up of cells.
Cells combine to form tissues, tissues form organs, and organs work together to form organ systems, which ultimately make up the entire organism.
Therefore, the cell is the basic building block, the structural unit, of any living organism.
Functional Unit:
Cells are capable of carrying out all the essential life processes like:
Nutrition: Obtaining and processing nutrients for energy.
Respiration: Exchanging gases (oxygen and carbon dioxide).
Excretion: Removing waste products.
Reproduction: Creating new cells and, in some cases, new individuals.
These processes, which are necessary for life, are all performed by the cell and its internal components (organelles).
The organized structure of a cell, including its membrane and organelles, enables it to carry out these diverse functions.
In essence, the cell is both the smallest independent unit of life and the unit responsible for all the functions that define life.