tools of a biologist
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Tools of a Biologist. Microscopes: number one tool of a biologist. Micro=Scope= Small-to view. A microscope is an instrument used to view very small objects. In biology we will use it to view…. living cells and unicellular organisms. - PowerPoint PPT PresentationTRANSCRIPT
Tools of a Biologist
Microscopes: number one tool of a biologist
• Micro= Scope=– Small -to view
A microscope is an instrument used to view very small objects.
In biology we will use it to view…. living cells and unicellular organisms.
Compound Light Microscope
There are 3 types of microscopes used in biology:
1. Compound light microscope-Compound-
look through 2 lenses at the same time in order to properly magnify the organism.
Total magnification:
low power:ocular lens x10low objective x4
-------------- x40
medium power:ocular lens x10low objective x10
-------------- x100
high power:ocular lens x10low objective x40
-------------- x400
Compound light microscope:
-light -light must pass through the diaphragm and through the
object.
-object must be “thin” or transparent so the light can
pass through it.-Diaphragm:
regulates the amount of light that can pass through.-Best setting of the diaphragm is #2
StainingThe purpose is to:
add color to a cell so that the cell and its structures can be seen more clearly through a microscope.
Limit of Resolution-is the point at which you see an item most clearly.
Any magnification above or below that point will results in the object looking blurry.
Type 2: Stereoscope-Used to view the surface of objects which are too large for light to pass through them.
-Uses 2 lights to illuminate the surface of the object.
-Stereo means “3 dimensional”
-Provides a 3-D detailed look at the surface of an object.
-look through2 ocular lenses
-magnifies between x10 to x60
Type 3: Electron Microscopes Uses electrons to form an image and NOT lightHas a very high limit of resolution.
-can see items very clearly at any magnification-can magnify up to 500,000x and still be clear
Object is placed in a vacuumNo airNo oxygenOrganism is DEAD
• Produces a 2-D, black and white image of inside of a cell.
Two types of electron microscopes:
1. T.E.M. ~ Transmission Electron Microscope
2. S.E.M. ~ Scanning Electron MicroscopeProduces a 3-D, black and white image of the surface of an object.
Additional tools of a biologist:
• Chromatography:Tool used to separate the components of a mixture by their different densities.
Link to graphing