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The Cell Theory




Slide 1

The Cell Theory

The Cell Theory

Slide 2

Some Random Cell Facts

Some Random Cell Facts

The average human being is composed of around 100 Trillion individual cells!!!

It would take as many as 50 cells to cover the area of a dot on the letter “i”


Slide 3

Discovery of Cells

Discovery of Cells

1665- English Scientist, Robert Hooke, discovered cells while looking at a thin slice of cork.

He described the cells as tiny boxes or a honeycomb

He thought that cells only existed in plants and fungi

Slide 4

Anton van Leuwenhoek

Anton van Leuwenhoek

1673- Used a handmade microscope to observe pond scum & discovered single-celled organisms

He called them “animalcules”

He also observed blood cells from fish, birds, frogs, dogs, and humans

Therefore, it was known that cells are found in animals as well as plants

Slide 5

150-200 Year Gap???

150-200 Year Gap???

Between the Hooke/Leuwenhoek discoveries and the mid 19th century, very little cell advancements were made.

This is probably due to the widely accepted, traditional belief in Spontaneous Generation.


-Mice from dirty clothes/corn husks

-Maggots from rotting meat

Slide 6

19th Century Advancement

19th Century Advancement

Much doubt existed around Spontaneous Generation

Conclusively disproved by Louis Pasteur

Pasteur: Ummm, I don’t think so!!!




Slide 7

Development of Cell Theory

Development of Cell Theory

1838- German Botanist, Matthias Schleiden, concluded that all plant parts are made of cells

1839- German physiologist, Theodor Schwann, who was a close friend of Schleiden, stated that all animal tissues are composed of cells.

Slide 8

Development of Cell Theory

Development of Cell Theory

1858- Rudolf Virchow, German physician, after extensive study of cellular pathology, concluded that cells must arise from preexisting cells.

Slide 9

The Cell Theory Complete

The Cell Theory Complete

The 3 Basic Components of the Cell Theory were now complete:

1. All organisms are composed of one or more cells. (Schleiden & Schwann)(1838-39)

2. The cell is the basic unit of life in all living things. (Schleiden & Schwann)(1838-39)

3. All cells are produced by the division of preexisting cells. (Virchow)(1858)

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