Transcript cells - AHS

Cells & Cell Organelles
Doing Life’s Work
AP Biology
2009-2010
Cytology – Study of Cells
Cell – Smallest unit of life that can carry out
all functions of living things.
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Cell Size
 Small cells function more efficiently
than large…. Why?
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Cell Size
•Advantage of many small cells –exchange
substances more readily - higher surface
area-to-volume ratio
•Substances do not need to travel as far to
reach the center of a smaller cell.
•Cell Races Activity
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Cell Size
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Discovery of Cells
Robert Hooke- 1665
 Looked at cork under
microscope
 Coined the term “cells”
 Later, scientists would
discover cells contain
living matter
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Anton von Leeuwenhook – 1670’s
 Used glass lens to magnify
 Simple microscope with only 1 lens
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The Cell Theory
Contributors
1. Matthias Schleiden – 1838 (botanist)
All plants are made of cells
2. Theodor Schwann – 1839 (zoologist)
All living things are made of cells
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The Cell Theory
Contributors (cont.)
3. Rudolph Virchow – 1855 (physician)
Cells come only from other cells
(Biogenesis)
Before this, spontaneous generation
was the accepted idea
Hey…Mice are
always coming
out of the hay!
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The Cell Theory States…
1. All living things are
made of one or more
cells
2. Cells are the basic units
of structure and
function in organisms
3. All cells arise from
existing cells
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Other discoveries made using microscopes
Louis Pasteur 1862.
Microscopic
organisms cause
disease.
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Other discoveries made using microscopes
Walter Fleming – 1882. First to see
chromatin in nucleus and watch cell
division.
Q: Explain the statement- “The progress of biology
often depends on advances of technology.”
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Types of Microscope
1. Compound Light Microscope – 2
lenses. (We use these in class)*
- magnification up to 1000x
2. Electron microscopes – use beam of
electron to map the specimen. Used
since 1950s.
-Magnification up to 1,000,000x
-Specimen is fixed and vacuum
sealed, must be dead
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Any
Questions?
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