Download The Cell Theory

The Cell Theory
Biology 11
Outcome 314-5: explain
the cell theory
Some Random Cell Facts
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The average human being is made of around
100 trillion cells!!
It would take as many as 50 cells to cover
the area of a dot on the letter i
Discovery of Cells
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1665 – Robert Hooke, (English)
discovered cells while looking at a thin
slice of cork.
He described them as tiny boxes or
honeycomb
He thought cells only exist in plants and
fungi
He didn’t know their real structure or
function
Anton van Leuwenhoek (Dutch)

1673 – Used microscope
to look at pond scum and
saw single celled
organisms
–
–
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Animalcules
He also looked at many other
things, including animals
Therefore it was well known
that cells were in animals and
plants
150-200 Year Gap
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Between these discoveries and the 19th
centruy there were very little advancements
made
This was probably due to the belief in
spontaneous generation.
19th Century Advancement
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Much doubt now over spontaneous
generation
Conclusiverly disproved Louis Pasteur
Development in Cell Theory
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1838 – German
Botanist, Schleiden,
concluded that all plant
parts are made of cells
1839 – German
Psychologist, Schwann,
stated that all animal
tissues are made of
cells
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1858 – German
Physician, Virchow,
after an intensive
study of cellular
pathology concluded
that all cells must rise
from preexisting cells
3 Basic Components of Cell Theory
1)
2)
3)
All organisms are made of one or more
cells
The cell is the basic unit of life in living
things
All cells were produced by the division of
preexisting cells
Modern Cell Theory
 Contains
one more statement
4) The cell contains hereditary
information (DNA) which is
passed on from cell to cell during
cell division.
The Cell
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All cells are basically the same in chemical
composition and metabolic activities
All basic chemical and physiological
functions are carried out inside cells
(movement, digestion, etc)
Cell activity depends on the activities of subcellular structures within the cell (organelles)
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Cell theory holds true for all living things no
matter how big or small, how simple or
complex
Since they are common, we can use the
information to tell us about living things (how
they grow or reproduce)
How has the cell theory been used?

The basic discovered truths about cells,
listed in the Cell Theory, are the basis for
things such as…
–
Disease, Health . Medical research and Cures
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AIDS, Cancer, Vaccines, Cloning, Stem Cell Research,
etc.