The Cell Theory
SOL BIO 2a
The Cell Theory
The development and refinement of
magnifying lenses and light microscopes
made the observation and description of
microscopic organisms and living cells
possible.
The Cell Theory
Many scientists contributed to the
cell theory
The Cell Theory
3 parts to the cell theory:
1. The cell is the basic unit of life
2. All living things are made of cells
3. Cells come from pre-existing cells
Anton van Leeuwenheok (1632-1723)
He invented the
first microscope.
Dutch scientist who
was the first to see
bacteria and
protists.
Leeuwenhoek’s Microscope
Robert Hooke (1635-1703)
He observed that
cork has small
regular boxes in
it that he called
“cells”.
Hooke’s cork cells
Robert Brown (1773-1858)
Scottish botanist
who noticed that
all cells have a
dark region that
he called a
“nucleus”
Theodor Schwann and Matthais Schleiden
stated that all living things are made of
cells. (1839)
Matthais Schleiden
(plants)
Theodor Schwann
(animals)
Rudolph Virchow (1821-1902)
German
scientist who
discovered
that all cells
come from
pre-existing
cells.
The Cell Theory
Continued advances in microscopy
allowed observation of cell organelles
and structure.
Electron Microscopes
Scanning Electron Microscope (SEM):
bounces electrons off of a whole goldcoated sample to create vivid 3-D images
Transmission Electron Microscope (TEM):
bounces electrons off of a sliced sample to
create very detailed images