Name the three parts of the
cell theory
The Cell Theory
1. All living things are composed of cells.
2. Cells are the basic units of structure and
function in living things.
3. All cells are produced from other cells.
1590
This father and son team are
given credit for inventing the
first compound microscope.
Hans and Zacharias Janssen
• Zhacharias most likely had help from his
father Hans.
• Could magnify 3 to 9 times (maybe up to 10x)
• Would be more than 50 years before the
microscope was used by scientists.
1665
English Scientist famous for
his microscope drawings
especially cork.
Robert Hooke
Hooke's microscope Courtesy - Billings
Microscope Collection, National
Museum of Health and Medicine, AFIP
Robert Hooke’s Drawing of Cork
• Thought the chambers
looked like little rooms in
the monastery.
• Called them “cells”
Robert Hooke - Published book in 1665 called
Micrographia (tiny drawings).
1674
Dutch lens maker who was
the first to identify bacteria by
looking at scrapings from his
teeth
Anton Van Leeuwenhoek
Leeuwenhoek was not a good
artist so he described in great
detail what he saw under the
microscope.
1838
This German botanist
studied plants and
discovered that all plants
were made up of cells
Matthias Schleiden
Matthias Schleiden (1804 – 1881)
All plants are made up of cells
1839
This German scientist extended
the work of his friend Matthias
Schleiden and discovered that
ALL cells (plants and animals)
were made of cells.
Theodor Schwann
Theodor Schwann (1810 – 1882)
 All animals are made up of cells
1855
German Doctor famous for
saying, “ominis cellula e cellula” all cells arise from other cells.
Rudolf Virchow
Virchow applied his ideas to
disease. He thought that all
disease was caused by cells that
did not function properly.
1864
This French Chemist disproved
the widely accepted theory of
spontaneous generation.
Louis Pasteur
Think about the seven scientists that we
have studied. Which three do you think
were the most important in the development
of the cell theory?
Support each choice with information from
your research.