why cells are called basic unit of life
Cell (biology) The cell (from Latin cella, meaning "small room"[1]) is the basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life. Cells are often called the "building blocks of life". The study of cells is called cell biology.
Protoplasm The word "protoplasm" comes from the Greek protos for first, and plasma for thing formed, and was originally used in religious contexts.[8] It was used in 1839 by J. E. Purkinje for the material of the animal embryo.[9][10] Later, in 1846 Hugo von Mohl redefined the term (also named as Primordialschlauch, "primordial utricle") to refer to the "tough, slimy, granular, semi-fluid" substance within plant cells, to distinguish this from the cell wall and the cell sap (Zellsaft) within the vacuole.[11][12][13] Thomas Huxley (1869) later referred to it as the "physical basis of life" and considered that the property of life resulted from the distribution of molecules within this substance.[14] The protoplasm became an "epistemic thing".[15] Its composition, however, was mysterious and there was much controversy over what sort of substance it was.[16]