Download NOTES: 7.1 - Intro to Cells

NOTES: 7.1 – Introduction to the Cell (“Life is Cellular”)
The Cell Theory
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MICROSCOPES
1.Light Microscope
2.Electron Microscope (1940’s)
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Light Microscope
 works by passing visible light through a thin section of specimen and then through glass lenses
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Electron Microscope (1940’s)
 uses electron beams which have shorter wavelengths of light (so you can see smaller objects…more detail)
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1) Scanning Electron Microscope
-electron beam scans the surface of a specimen
2) Transmission Electron Microscope
-electrons transmitted through specimen
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**Disadvantages to EM:
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ALL CELLS:
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(preparation steps kill living cells)
CELLS CAN BE CLASSIFIED AS:
1. PROKARYOTES
2. EUKARYOTES
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**One of the key structures / organelles that distinguishes a eukaryotic cell from a prokaryotic cell is the:
NUCLEUS
 membrane-bound organelle in eukaryotic cells;
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-enclosed by a nuclear envelope
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