CBSE Class 9 Answered
The cell is called the structural and functional unit of life because it is the basis to which all the major organs and tissues in the body are made up of. A group of cells with the same function grouped together makes up a tissue, tissues come together to form organs, and different organs form a system. Without cells all life would die.
Working through the tissues, the cells build up the body and carry on its different activities. They are recognized on this account as the units of structure and of function, and are the "individuals" in the body organization. Among the most important and interesting of the activities of the cells are those by which they build up the body, or cause it to grow.