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Cell Theory

By 24moonelog
  • 340 BCE

    Forming Life

    Aristotle came up the theory that life was formed from epigenesis. This was one of the first theories that there was a genuine reason for life being formed.

  • Invention of Compound Microscope

    Zacharias Johnson developed the first compound microscope in 1590 with his father, it allowed for tiny things to be seen by humans, which would eventually lead to Cell theory.

  • Early Discoveries of Photosynthesis

    Jan Baptist van Helmont discovered possible photosynthesis by seeing that a willow tree weighed more than the original soil it displaced. It's not exactly sure when but the experiment was conducted over a five year period. This helped towards disproving spontaneous generation by giving an example of something naturally growing with scientific reason.

  • The discovery of "cells"

    Robert Hooke, using a microscope, looked at some cork and saw many small boxes, he called these "cells" like the rooms monks lived in at monestaries.

  • Discovery of Bacteria

    Anton van Leeuenhoek made lenses for microscopes, using these he discovered bacteria inside of his mouth. He originally called them "Animolecules" because he thought they looked like tiny animals. He reported his findings of these creatures to the royal society. This proved that there were tiny beings capable of performing all functions of life.

  • All life originates from cells

    Lorenz Oken claimed that all organism consist of and originate from cells. He was one of the first scientists to have any ideas other than spontaneous generation.

  • Discovery of Nucleus

    Robert Brown discovered a nucleus in plant and animal cells, this is where cell replicants are split, so this helped prove that living things have to come from pre-existing lifeforms.

  • Discovery of Plant Cells

    Matthias Schledein was a German botanist who saw that all parts of plants of all plants are made of cells.

  • "All life is made of cells"

    Theodore Schwann was a zoologist who saw that all animals are also made of cells after working with Schledein. He published the book "Microscopic Investigations on the Accordance in the Structure and Growth of Plants and Animals" stating their discovery that all life is made of cells.

  • Humans are Made of Cells

    Albrecht von Roelliker discovered that the sperm and egg were made of cells, so humans were made of cells from beginning to end. This helped to further cell theory by proving that even humans are fully made of cells.

  • How Life is Created

    Rudolph Virchow stated that all life must come from pre-existing lifeforms, this was seen as radical at the time, but he was one of the first scientists to disagree with spontaneous generation.

  • Disproving Spontaneous Generation

    Louis Pasteur proved spontaneous generation by leaving broth in two separate containers. One would be airtight while the other was exposed. After several weeks, the closed one had no bacterial growth, but the open one did. Using knowledge from scientists before him, Louis decided that it was conclusive evidence to disprove spontaneous generation.