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384 BCE
Aristotle
First person to theorize that genes do exist and that each living thing has its own set of genes, which gave all living things a parent and predictable offspring. Aristotle also noticed that most offsprings looked like their parent.
(https://prezi.com/m/qh1-tt8cppxl/cell-theory-timeline/) -
Zacharias Jansen
Known for inventing the compound optical microscope by combining two convex lenses within a tube. The microscope he made was created with the help of hans, made it more practical for scientists to observe cells. The cell theory was first discovered after Janssen developed the microscope.
(http://www.smithlifescience.com/celltheory.htm) -
Jan Baptist Van Helmont
Jan believed in spontaneous generation, and proved it to be true. He contributed to the Cell theory by making an important early contribution to photosynthesis. Jan also recognized the existence of discrete gases and identified Carbon Dioxide.
(https://prezi.com/m/daxti_3duv7g/cell-theory-timeline/) -
Robert Hooke
Known for viewing a thin cutting cork underneath a three-lense compound microscope in which he discovered empty spaces contained by walls, and termed them cells. Hooke later calculated that the number of cells in a cubic inch to be 1,259,712,000. This lead to Hooke’s interest in studying plants in which he came up with the idea of cells. Without Hooke, cells would not have been discovered for hundreds of more years. (http://www.softschools.com/timelines/cell_theory_timeline/96/) -
Anton Van Leeuwenhoek
Known for building an improved single-lense microscope which allowed him to view cells closer. While observing pond water, he discovered single-celled organisms that he called “animalcules”. Anton was the first scientist to observe living cells and bacteria cells. This contributed to the theory by discovering organisms with one cell. (http://www.softschools.com/timelines/cell_theory_timeline/96/) -
Lorenz Oken
Oken came up with a new system of animal classification that demonstrated the path of evolution. Oken also stated that “All living organisms originate from and consist of cells”. (https://prezi.com/m/2neqtvrncc3m/cell-theory-timeline/) -
Robert Brown
Brown was a Scottish botanist known for discovering the nucleus of the cell while looking at a plant cell. The discovery of the nucleus by Brown showed that all living things were made up of one or more cells.
(http://www.smithlifescience.com/celltheory.htm) -
Theodor Schwann
Known for noticing great similarities between plant and animal cells, which lead to the creation of the cell theory which states that all living things are made up of one or more cells. Schwann also wrote the first two parts of the cell theory. (http://www.softschools.com/timelines/cell_theory_timeline/96/) -
Matthias Schleiden
Known for discovering that all plants are made up of cells through observing plant cells using a compound microscope. Schleiden wrote “contributions to Phytogenesis,” in which he stated that the different parts of the plant organisms are composed of cells or derivatives of cells. Along with Theodor Schwann, he created the cell theory which states that all living things are made up of one or more cells.
(https://www.britannica.com/biography/Matthias-Jacob-Schleiden) -
Albrecht Von Roelliker
Known for discovering that Sperm and Eggs are also cells. This contributed to the cell theory because later, instead of spontaneous generation, they were able to discover that sperm and egg cells are needed to reproduce other living things. (http://bitesizebio.com/166/history-of-cell-biology/) -
Rudolf Virchow
Known for setting out methods and objectives of pathology and demonstrating that the cell theory applied to diseased as well as healthy tissue. Virchow also proposed the idea that cells come from preexisting cells.
(http://www.smithlifescience.com/celltheory.htm) -
Louis Pasteur
Pasteur was the first scientist to prove that cells can only come from preexisting cells. Pasteur proved this to be right by creating an experiment that showed cells would only grow in broth if air was exposed.
(http://www.smithlifescience.com/celltheory.htm)
