microscopeacts2

Act #7: How large is the FIELD OF VISION?

1) Use a small clear ruler or protractor as the �specimen�.
2) Find the millimeter divisions under scanning power. How many lines can you fit? Draw the field exactly the way you see it in the microscope. The number of lines of the ruler represents the size of the FIELD OF VISION.
3) Now change the objective lens to low power. How many lines can you fit? Draw the field exactly the way you see it in the microscope.
4) Finally change the objective lens to high power. How many lines can you fit? Draw the field exactly the way you see it in the microscope. Calculate the F.O.V. for the high power.
5) Copy down this table:

         Total Magnification                                  Field of Vision (F.O.V.) in mm and microns
                         40 x
                         100 x
                         400 x

Act #8: Estimating the sizes of objects using the F.O.V

To estimate the sizes of objects and organisms under your microscope, I wouldn�t expect you to use a ruler to calculate the F.O.V. every time. Instead use the table above and estimate the sizes to the best of your ability.

1) Example #1:

                          magnification = 40 x
What is the approximate size of the object?

2) Example #2:

                           magnification =100x
What is the approximate size of the object?

3) Example #3:

                            magnification =400x
What is the approximate size of the object?

Act # 9: The Cell

Robert Hooke coined the tiny compartments he saw using the microscope of sliced cork as "cellulae" or cell. Let�s try to re-create what Hooke saw.

1) Shave a piece of cork (as thin as you can). Remember, in order for your microscope to work, light has to go through your object or organism.
2) Make a wet mount slide of the cork.
3) Adjust the diaphragm so that enough light is going through.
4) Find the �cells� under high power and sketch.
5) Label the magnification and the size of the cork cell.
6) What do you think? Are these cells alive or dead?

Act #10: Other Kinds of Microscopes

You�ll need your lab manual for this exercise. Read pgs. 37-40 in the manual about microscopes. Please answer the post lab questions on pg. 41.

EXTRA CREDIT ACTIVITY

1) What are several difference (just by looking at the two microscopes) between a light, compound microscope and a binocular or stereomicroscope?
2) Using a binocular microscope, find some odd/ strange/ enlightening objects on US currency. Try some older $1, $5, $10, or $20. Make a list of those objects that is naked to the human eye for some extra credit. You�ll need to find at least 5 items.
3) View a baby convict using a binocular microscope. Sketch the fish and label the total magnification.