Cell Theory

Cell Theory Matthias Jakob Schleiden (1804 – 1881) German botanist, concluded that all plant tissues are composed of cells and that a plant arose from a single cell.   He declared that the cell is the basic building block of all plant matter. “All plants and their parts are made of cells.”

Cell Theory Theodor Schwann (1810 – 1882) German physiologist, generally considered the founder of modern histology, the study of the structure of plant and animal tissues. He pulled existing observations together into theory that stated:  Cells are organisms and all organisms consist of one or more cells.  The cell is the basic unit of structure for all organisms and that plants and animals consist of combinations of these organisms which are arranged in accordance with definite rules. In other words, “The cell is the basic unit of life.”

Cell Theory Rudolf Virchow (1821 – 1902) German pathologist, archaeologist, and anthropologist, the founder of cellularpathology. “All cells develop only from existing cells.”

Cell Theory The generally accepted parts of modern cell theory include: All known living things are made up of one or more cells. All living cells arise from pre-existing cells by division. The cell is the fundamental unit of structure and function in all living organisms. The activity of an organism depends on the total activity of independent cells. Energy flow (metabolism and biochemistry) occurs within cells. Cells contain hereditary information (DNA) which is passed from cell to cell during cell division. All cells are basically the same in chemical composition in organisms of similar species.