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- Biologists use different types of microsscopes and various tools and techniques to study the structure and function of cells.
- The compound light microscope illuminatees a specimen with a beam of light. Two sets of lenses, the ocular (located in the eyepiece) and the the objective (located above the specimen), magnify a specimen which is mounted on a prepared slide.
- - Two important concepts relating to microscopes:
- ) Magnification is the ability of a microscope to make an image appear larger.
- ) Resolution is the ability to show details clearly.
- An electron microscope uses a beam of ellectrons instead of light rays to produce an image magnified at least 100 times more than a light microscope.
- Scanning electron microscope (SEM) reveaals surface details of specimens.
- Transmission electron microscope (TEM) rreveals the internal structure of specimens
- The International system of measurment iis known as the Metric system.
- Fractions and multiples of ten are expreessed by the use of prefixes.
Metric Prefixes
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Base Units
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micro = 10-6
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Distance = meter
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milli = 10-3
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Volume = liter
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centi = 10-2
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Mass = gram
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kilo = 10+3
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Time = second
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mega = 10+6
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Temp. = Kelvin
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