Cell Theory and Cell Study

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Cell Theory and Cell Study
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The Cell Theory

• The cell is the basic unit of structure of all
  living things.
• All living things are made up of cells.
• The cell is the basic unit of function of all
  living things.
• Cells come from pre-existing cells.

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Exceptions to the Cell Theory

• These are facts that can not be explained by the
  Cell Theory.
• Viruses are not made up of cells, but they do
  contain genetic material.
• The first cell could not have arisen from a
  previously existing cell, Scientists dont know
  the origin of the first cell.

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History of Cell Study

• Scientists did not know much about cells until
  the discovery of the microscope.
• Cells are so small they can not be seen w/o a
  microscope.
• Anton van Leeuwenhoek- Dutch naturalist (1600s).
  Developed the first microscope.
• Robert Hooke- English (1665) was the first to
  develop a compound microscope. He came up with
  the term cell.

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History cont..

• Robert Brown- (1831) discovered the nucleus of
  the cell.
• Matthias Schleiden- (German, around 1830s) a
  Botanist, concluded that all plants were made up
  of cells.
• Theodor Schwann- (German, worked during the same
  time as Schleiden), studied animal cells.
  Concluded that animals were made up of cells.
• Rudolf Virchow- (1858) concluded that all new
  cells must come from previously existing cells.

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The Compound Microscope

• Microscopes are used to study materials that
  cant be seen with the naked eye.
• Microscopes use two lenses (compound microscope)
  to increase the size of a specimen.
• A specimen must be thin enough for light to pass
  through it.
• The total magnification of an object is found by
  multiplying the magnification of the objective x
  the magnification of the eyepiece.