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384 BCE
Aristotle
He took many experiments to come up with the theory on how embryos generate and develop. Also came up with the theory on how organisms develop gradually from undifferentiated material; also known as epigenesis. info: https://embryo.asu.edu/
pic: www.researchgate.net -
Zacharias Jansen
Invented the compound microscope that allowed scientist to observe cells. info: http://fig.cox.miami.edu/
pic: micro.magnet.fsu.edu -
Jan Baptist van Helmont
Partially discovered the process of photosynthesis by observing plants mass increasing because they are absorbing water. info: https://www.britannica.com/
pic: www.timetoast.com -
Robert Hooke
First to use the compound microscope to observe what he called cells, which he observed by looking at a piece of cork. info: https://science.howstuffworks.com/
pic: timetoast.com -
Anton van Leeuwenhoek
Learned to grind lenses and assemble them into simple microscopes; discovered blood cells. info: https://science.howstuffworks.com/
pic: www.timetoast.com -
Lorenz Oken
Proved all things originate and are made of cells. Believed all cells came from pre-existing cells. info: http://fig.cox.miami.edu/
pic: biologydictonary.net -
Robert Brown
Discovered the nucleus of plant cells while observing their cells through a microscope. info: http://fig.cox.miami.edu/
pic: www.emaze.com -
Matthias Schleiden
Looked at many plant samples on a microscopic level. He was the first to observe that all plants, and different parts of the plant, were made up of cells. info: https://science.howstuffworks.com/
pic: sites.google.com -
Theodor Schwann
Schwann came to similar conclusions of Schleiden while studying animal samples and examining similar things. First cell theory: all living things are made of cells. info: https://science.howstuffworks.com/
pic: amoebamike.wordpress.com -
Albrecht von Roelliker
He discovered using the microscope that cells were present in human sperm and egg. All humans are formed of cells. info: softschools.com
pic: kingscollections.org -
Rudolf Virchow
Rudolf Virchow extended the work of Schleiden and Schwann by proposing that all living cells must rise from pre-existing cells. Laid the groundwork for studying disease on a cellular level. info: https://science.howstuffworks.com/
pic: timetoast.com -
Louis Pasteur
Set up experiments of pasteurization to disprove spontaneous generation. info: https://science.howstuffworks.com/
pic: pinterest.com
