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Hooke
Contribution: Hooke discovered plant cells using an early microscope. He did not realize the cells were the building blocks of life. He assumed the empty spaces might transport fluids in plant-life.
How: Hooke discovered the cell while observing cork tissue. The cork consisted of tiny compartments in which he called cells. He called them cells because they reminded him of the cells in a monastery. -
Hooke (continued)
Disproved Previous: He help in proving Spontaneous Generation as false. Spontaneous Generation is the supposed production of living organisms from nonliving matter. Because he discovered cells, his successors were able to use his work to completely disprove Spontaneous Generation. -
Leeuwenhoek
Contribution: He was the first person to observe and describe bacteria, yeast plants, unicellular organisms in a drop of water, and the circulation of blood corpuscles in capillaries. When examining pond water, he observed protists, which he called 'animalcules'. -
Leeuwenhoek (continued)
How: Leeuwenhoek discovered how to grind and polish tiny lenses to get a curvature with magnifications up to 270x diameters; a major improvement from Robert Hooke's. The lenses led to him making the first practical microscopes.
Disproved Previous: The popular belief of Spontaneous Generation imposed that all life arose abruptly from inanimate matter was disproved by Leeuwenhoek. -
Brown
Contribution: Brown discovered the nucleus in the plant cells.
How: Brown noticed pollen traveling in and out of ovals of Asclepiad and orchid cells. He named this oval the the "nucleus". He proposed the possibility that the nucleus was at the center of cellular creation.
Disproved Previous: Many scientists saw the nucleus but deemed it was unimportant; Brown proved its significance. -
Schleiden
Contribution: Schleiden shows that cells are the basic building blocks of all plants.
How: He inspired Schwann to demonstrate that animals are also made of cells. Before Schleiden, botany (the study of plants) focused mainly on the forms of plants, mostly relying on dried specimens. Schleiden urged scientists to study live plants using microscopes. -
Schleiden (continued)
Disproved Previous: Schleiden rejected the argument that life can be explained by physical and chemical laws alone. He helped disprove the belief of Spontaneous Generation. -
Schwann
Contribution: Schwann proved that animals, and plants alike, are made of cells and that living things grow and develop when cells multiply.
How: He observed cells in all samples of animal tissue. He put his work in a theory -- Cells are organisms and all organisms consist of one or more cells, and the cell is the basic unit of structure for all organisms. -
Schwann (continued)
Disproved Previous: The conclusion ended disputes over plants and animals being fundamentally different in structure. Schwann also opposed Spontaneous Generation the then popular belief that a mysterious life force made living things different from other material. -
Virchow
Contribution: Virchow believed that the cell is the basic unit of human life and that disease results from disruptions in the function of cells.
How: He showed that the effects of disease could be detected by observing cells through a microscope.
Disproved Previous: Virchow added another part to cell theory that states all cells develop only from pre-existing cells.
