CELL THEORY

• Zacharias Janssen and Hans were a contributor on the discovery of the cell. The two are

  known for their invention the compound optical microscope. They invented the microscope in 1590’s.

  Their invention played a great role in the discovery of the cell theory, by making it easier and more

  practical when observing cells
• Robert Hooke was a British scientist. In 1665 Hooke made an important discovery under a

  compound optical microscope. When he looked at a thin slice of cork under his microscope.
• he saw

  that the cork was made-up of many tiny units’ room like structure, he saw tiny little shapes that looked

  like little rooms with walls around each of them.
• cellulae” or simply “Cell”. This Latin

  word means "little rooms”. That was the first discovery of the cell
• In 1674, Anton van Leeuwenhoek

  became the first to observe live cells. It became possible for Leeuwenhoek to observe the cells -living

  cells- clearly because of his invention, the microscope with improved lenses that could magnify objects

  from 270 to 300-fold.
• Who was the first botanist to state that cells are the building blocks of all plants? (1838)

  Matthias Jakob Schleiden
• Theodor Schwann (1838) stated that cells are the fundamental units of

  animals too. These statements ended the notion that plants, and animals have fundamental differences

  in structure.

  Their discoveries led to the formulation of the ‘Cell Theory’ which states that cells are the basic

  units of all living organisms (plants and animals). But the cell theory failed to explain how new cells

  arise.
• In 1855, Rudolf Virchow, a German physiologist stated in German ‘Omnis cellula e cellula’ which

  means that new cells come from already existing cells (Wakim et.al., Discovery of Cells and Cell Theory

  2020, Butte College).