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Unit C_ Cycling of Matter in Living Systems - Ms Redding's Weebly

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Unit C_ Cycling of Matter in Living Systems - Ms Redding's Weebly Powered By Docstoc
					  Unit C: Cycling of
Matter in Living Systems
• Aristotle is known as “The
  Father of Biology.”
• He was one of the first Greek
  philosophers who used the
  Scientific Method of observing,
  recording, reasoning, and
  interpreting in attempt to
  explain the world around him.
3000 years ago: Egypt &
  Mesopotamia
• Glass – the material for
  lenses

Early 1200s: Roger Bacon
• Described how crystal
  lenses might improve
  vision of the elderly
Late 1200s: Salvino degli
  Amati (Italy)
• Made the first pair of
  spectacles
• Lenses were fashioned
  by craftsmen
• A new branch of
  physics, called optics,
  was born to explain
  the movement of light
1600s: Telescopes & Microscopes
• 1595 Hans and Zacharias Janssen (Holland) invent the
  first 2-lens compound light microscope
• 1665 Robert Hooke (England) developed a 3-lens
  system.
  – Hooke observed thin slices of cork and saw what he called
    cells
• 1665 Antoni van Leeuwenhoek, an expert lens crafter
  was the first to reveal the microbial world
  – His daughter helped him make his microscopes
  – They were the first to see the movement of different types
    of cells we now call protozoa, sperm, and bacteria
Microscope by Hans and Zacharias Janssen
Figure C1.3 Hooke’s Mircroscope
• As lens technology improved over the years,
  the world’s knowledge of the microscopic
  world increased, allowing us to solve many
  problems




Red Blood Cells        Human         E. Coli bacteria
                  Immunodeficiency        cluser
                    Virus (HIV)
• A MICROSCOPE is an instrument with a lens
  or system of lenses for magnifying specimens.
• In order to use a microscope you must be
  familiar with the following:
    1.   Microscope Structures & Functions
    2.   Microscope Handling Protocol
    3.   Calculating Magnification
    4.   Unit Conversion
    5.   Field of View
1. Eye Piece or Ocular Lens.
2. Coarse Focus Adjustment
3. Arm
4. Stage Clip
5. Fine Focus Adjustment
6. Base
7. Lamp
8. Diaphragm
9. Stage
10.Objective Lenses
11.Revolving Nosepiece
12.Body Tube
       Handling A Microscope
1. Always carry the microscope in an upright
   position with two hands: one on the base,
   the other on the arm.
2. Use only lens paper to clean lenses.
3. Make sure the power switch is off before
   you plug it in.
4. Never allow the lens to touch the slide.
5. Never attempt to repair the microscope
   yourself.
6. Use stage clips to hold the slide steady.
7. Always start to focus on the low-power
    objective lens first.
8. Use the coarse focus first.
9. Never use the coarse focus on the high-
    power objective lens.
10. When you are finished:
     a)   Rotate to the low-power objective lens
     b)   Remove the slide
     c)   Turn the microscope off
     d)   Put the dust cover on
     e)   Remove the power cord from the socket by the
          plug.
       Calculating Magnification
 • The MAGNIFICATION tells the reader how
   much larger (or smaller) the picture is than
   the real size of the item

 • In order to calculate the magnification of a
   system use the following formula:

Magnificat ion  objective lens ocularlens 
                    pg. 244 Calculating Magnification



What is the magnification if the following
  combinations of lenses are used?

a) A 2.5X low-power objective lens and a 10X
ocular lens?
                                          25X

b) A 100X high-power objective lens and a 10X
ocular lens?
                                         1000X
             Unit Conversion
Line Master 1: Units of Measurement

          Unit            Equivalent Measurement
Centimetre (cm)           1/100 metre; 10–2 m
Millimetre (mm)           1/10 centimetre; 10–3 m
Micrometre—also known 1/1000 millimetre; 10–6 m
 as the Micron (μm)
Nanometre (nm)            1/1000 micrometre; 10–9
                            m
Angstrom (Å)              1/10 nanometre; 10–10 m
                        Unit Conversion



Complete the following table.


             40cm          ______μm
            ______ cm           1.6 nm
             400 A         ______ mm
               Field of View
• The FIELD OF VIEW is the entire area that you
  see when you look through the microscope.
• Activity: Look at your partner through a paper
  towel roll. Now, get your partner to walk
  closer to you. Do you see more or less of your
  partner? Does your partner appear larger or
  smaller when he or she is closer to you? The
  same idea applies to magnification:
• Magnification increase the size of what you see
  BUT decreases the amount of the object in view
• Since the field of view decreases in size in direct
  proportion to the increase of the magnification,
  we can calculate the size of the other fields of
  view.
• For example: If the field of view is 4000μ at
  40X, it will be 10 times smaller at 400X, or
  400μ in size.
                     Calculating Field of View


Complete the following table:


     Lens          Field of view   Field of view
   Magnification        (mm)             (μm)
      40                 4             4000
      100               1.6            1600
      400              0.4              400

				
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