The Cell Theory

1. All living things are composed of cells.

2. Cells are the basic unit of structure and function in living things.

3. New cells are produced from existing cells.

These people contributed to the creation of the cell theory.

Anton Van Leeuwenhoek

- Perfected the microscope.
- Observed bacteria and protozoa which he called "Animalcules" in 1838.

Matthias Schleiden

- German zoologist that concludes that all plants are made of cells in 1838.

Theodor Schwann

- German zoologist that concludes that all animals are made of cells in 1839.

Rudolf Virchow

- German physician/pathologist and proposed that all cells come from existing cells in 1855.

These scientists contributed to cell knowledge.

Janet Plowe

- Demonstrates that the cell membrane is a physical structure, not an interface between lipids.

Lynn Margulis

- Proposes a theory that states that certain organelles were once free-living cells themselves.

Garth Nicolson


S.J. Singer


Fluid Mosaic Model

- Created by Singer and Nicolson that showed the cell membrane as a phospholipid bilayer made up of smaller pieces.