CELLS

THE CELL THEORY

Zacharias Jansen (1588-1631)
- invented one of the microscope's first prototype

Robert Hooke (1635-1703)
- reported some clear drawings of the plant cells
- introduced the term cell after observing boxlike structures from cork slices

Anton van Leeuwenhoek (1632-1723)
- reported the discovery of blood cells, sperm cells

*FORMULATED AFTER 200 YEARS AFTER THE INVENTION OF MICROSCOPE

Lorenz Oken (1779-1851)
- postulated that all organisms originate from and consist of cells

Robert Brown (1773-1858)
- discovered the nucleus

Felix Dujardin (1801-1860)
- sarcode, living substance within the cells was discovered (1835)
- the term was changed to protoplasm by Jan Evangelista Purkinje (1787-1869)

Matthias Schleiden (1804-1881)
- said that plants are made up of cells

Theodore Schwann (1810-1882)
- said that animals are made up of cells

Rudolf Virchow (1821-1902)
Concluded that
- the cell is the basic and structural unit of life
- every cell is formed from pre-existing cell


THREE PRINCIPLES OF THE CELL THEORY

• All organisms are composed of one or more cells
• Cells are the basic unit of organization of all organisms
• Cells arise only by division of a previously existing cell