Sec __ Name: _Experiment: Unicellular and Multicellular

Organisms and The Resolving Power of theMicroscope (S. Science 10-7-4c)

Purpose: We will learn that the materials have:depth as well as length and width and that you\need to shift your focus as you view in order toisee details at various depths. Both light andresolving power are reduced as magnification isincreased.

Materials: microscope slide of ameba, slime mold2 different colored fiberstnicroscope water microscope slides

jAethods:I. Observe the prepared slide of the ameba. Tryb determine if it is one cell or a group of cells.'"henin results record if it is unicellular or

multicellular.2. Repeat step 1 but this time with the slime mold.

3. Mount 2 different colored cotton fibers across each other in a drop of water on amicroscope slide. Cover the slide with a cover glass. Be careful not to trap air underthe cover glass. Adjust the diaphragm and bring a fiber into sharp focus with the lowpower of your microscope.4. Record the fiber colors as they appear under the microscope.5. As you examine the fibers, shift the focus by turning the fine adjustment back andforth slowly. Describe any changes in the appearance of the fibers.6.. Explain why these changes occur.7. Draw a picture of these fibers in the circle provided. How can you determine whichfiber is on top when you look through the microscope?8. Move the fibers to the center of the low - power field and shift to the high powermagnification. Compare the brightness of the low - power field to the high - powertil3ld.

9. Bring the fiber into the sharpest possible focus with the fine adjustment. Record ifthe depth of focus is as great with high power as with low power?

Results:1. ameba: _2. slime mold: _4. Color of the two fibers: _5. Appearance of fibers: _6. Why changes occur: _7. How you know on top: _8. Difference of brightness: _9. Difference of sharpness: _

x

Sec __ Name: . _Conclusions:

1. Give the function of each of the following parts of the microscope:Eyepiece:

Stage:

Stage clips:

Diaphragm:

Low - power objective:

High - power obiective:

Coarse adjustment:

Fine Adiustment:

Mirror:

2. Which direction should you focus the low - power objective?

3. Which adjustment sharpens the focus most precisely?

Discussion:

1. Which objective has the greater amount of magnification?

2. Break the word microscope into two parts, what do each of the parts mean?micro - scope -

3. How is the image of an object seen through the high-power objective different fromthe image seen through the low-power objective?

4. Besides size, how is the object seen through the microscope differ from the way theobject normally looks?

5. When you move the slide to the left, in what direction does the image appear tomove?

6. Explain why a specimen to be viewed under the microscope must be thin?

7. Why should you use a piece of lens paper only once?

8. Suppose you were observing an organism through the microscope and not:ceci t~latit moved toward the bottom of the slide and then it moved to the right. What does tllistell you about the actual movement of the organism?

9. In the previous chapter we learnt that biology means the study of life. ReadGenesis 2:7 and list the two components that make up the living person.

10. In the previous number of labs we've discussed the Biblical differences of humansand animals. Creeping into our society's thought is a New Age attitude of placinganimal (and in some cases plant) rights equal to or even above humans. Use God'sinstruction in Lev. 24:17,18,21 to comment on God's relative value of human and thenanimal life.