In 1838, a German botanist, M.I.Schleiden studied the plant cells and emphasized that "cells are organisms and entire animals and plants are aggregations of these organisms arranged according to definite laws. "In 1839, another German zoologist T. Schwann stated "we have seen that all organisms are composed of essentially like parts namely of cells." The deductions of the two microscopists (Schleiden and Schwann) formed the basis of what came to be known as the cell theory. The cell theory holds that all living matter, from the simplest of unicellular organisms to very complex higher plants and animals, is composed of cells and that each cell can act independently but functions as an integral part of the complete organism.
Cell theory is a theory that explains that properties of cells. The three parts of cell theory are:
1. All cells come from preexisting cells.
2. All living organisms are made up of one or more cells.
3. Cells are the basic unit of life (structure, organization and function)
Today, the cell theory holds true for all living organisms. The theory was developed due to the observations of Hooke, Leeuwenhoek, Schleiden, Schwann, Virchow and many more.
It was Robert Hooke who first saw the cells through a compound microscope; he described the little pores to be compartmentalized and looked like "cells".
Anton Van Leeuwenhoek was the first to see living cells under a compound microscope created by Zacharias Jansen.
Johann Jacob Paul Moldenhawer and Ludolph Christian Treviranus proposed that cells can be separated into individual units. While it was Henri Dutrochet who finalized that cells are the fundamental elements of organizations.
The Cell Theory has been supported by Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. Schwann and Schleiden were the first to say that cells are the basic unit of life. While it was Virchow who concluded that all cells come from preexisting cells.