Presentation on theme: "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."— Presentation transcript:
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 x10 low objective x x40 medium power: ocular lens x10 low objective x x100 high power: ocular lens x10 low objective x 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
Staining The 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 through 2 ocular lenses -magnifies between x10 to x60
Type 3: Electron Microscopes Uses electrons to form an image and NOT light Has 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 vacuum No air No oxygen Organism 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 Microscope Produces a 3-D, black and white image of the surface of an object.
Additional tools of a biologist: Chromatography : Chromatography Tool used to separate the components of a mixture by their different densities.