The theory that the cell is the basic biological unit of all living organisms has been approved .
The Cell theory , first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann has been thoroughly discredited . It states that all organisms are composed of one or more cells , that cells are the fundamental unit of structure and function in all living organisms , that all cells come from pre-existing cells , and that all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells .
Cell -LRB-biology-RRB-