Homework answers / question archive / LAB 2: MICROSCOPY THE MICROSCOPE AND YOUR EYES Students often wonder if they should remove their glasses when using a microscope

LAB 2: MICROSCOPY THE MICROSCOPE AND YOUR EYES Students often wonder if they should remove their glasses when using a microscope

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LAB 2: MICROSCOPY

THE MICROSCOPE AND YOUR EYES

Students often wonder if they should remove their glasses when using a microscope.  If you are nearsighted or farsighted, there is no need to wear your glasses.  The focus adjustments will compensate.  If you have astigmatism, however, you should wear your glasses because microscope lenses do not correct for this problem. You should still wear your glasses when working with the virtual microscope.

 

PROCEDURE 1: INTRODUTION TO THE MICROSCOPE AND ITS PARTS

 

1. Go to VIRTUAL MICROSCOPE and select the LAUNCH button
2. Click on the GUIDE tab located at the bottom of the home page.
3. Click through the six parts of the Guide, starting with the Introduction. You can use the arrows at the bottom of the Guide box to guide you through the chapters.
4. When you have completed all six sections, click Close.
5. Next click on the LEARN tab which will take you to an image of a microscope with question marks.
6. Starting at the top of the microscope, click on the question marks identifying the parts of the microscope.
7. Read the description of the part of the microscope and take notes as needed.
8. Continue clicking on question marks until all turn to green check marks.
   1. Do not forget to click on the question marks for items associated with the microscope.
   2. You may click on any green check mark to review any part of the microscope.
   3. Use the Microscope Parts checklist on the next page to ensure all parts have been identified.
9. Click on the Next button (bottom right).
10. Start on the left and click on the question mark. When the lens enlarges, click on each question mark until each turns into a green check mark. Read the descriptions and take notes as needed.
11. Click on the Next button (bottom right).
12. Click on the Dry Slide and Oiled Slide buttons to see the difference in why immersion oil is used for the 100X objective lens.
13. Click on the Next button (bottom right).
14. Click on the Eyepiece Options and Lens Options to learn about calculating total magnification. Try all combinations and see how the Letter e slide image changes.
15. Scroll down to complete the next portion of the exercise.

 

 

 

 

 

MICROSCOPE PARTS

Identify all parts of the microscope and associated items. 

On/Off Switch
Arm
Eyepiece/Ocular
Nosepiece
Objective lenses
Diaphragm
Base
Immersion Oil
Lens Wipes
Stage
Stage Adjustment Knob
Coarse Adjustment Knob
Fine Adjustment knob
Slide/Slide Box

 

QUESTIONS

1.  What is the proper way to carry a microscope?

 

2. What is the typical magnification of an ocular lens?  What other magnifications are possible?

 

3. What is the magnification of the following objective lenses? 
   1. Scanning (red ring) =
   2. Low-power (yellow ring) =
   3. High power (blue ring) =
   4. Oil immersion (white ring) =

 

4.  Why do you use immersion oil with 100x objective lens?
5. What is the total magnification of a sample with an ocular lens power of 15x and using a 40x objective lens?

 

6. What is a diaphragm.  What does it do?

 

 

PROCEDURE 2: HOW TO USE A COMPOUND MICROSCOPE TO VIEW SLIDES

 

1. Click on the Explore link (bottom of the home page).
2. Click on the question mark on the slide box.
3. In the Slide Catalog, click on the Sample Slides.
4. Click on the Letter E slide. It will automatically be placed on the stage of the microscope.
5. When the Microscope View window opens, make sure that the 4X circle is highlighted in blue.
   • NOTE: Always begin examining slides with the lowest power objective.
6. Use the slider under Coarse Focus to find the E.
   • NOTE: The coarse adjustment knob should only be used when you are viewing a specimen with the 4X objective lens.
7. Then use the slider under Fine Focus to make the image “crisp and clear.”
8. You can click on the E in the viewing window to move the image and visualize different parts.  Sketch your view of the letter E at 4X in the results area (next page).
9. Next click on the 10X circle. The nosepiece on the microscope will rotate automatically.
10. Repeat steps 6 – 8 to see part of the E. Sketch your view of the letter E at 10X in the results area.
11. Click on the 40X circle and repeat steps 7 & 8. You may need to use the slider under Light Adjustment for better visualization. Sketch your view of the letter E at 40X in the results area. Click on the 100X circle.  A notice to add immersion oil will open.
12. Click on the question mark on the immersion oil bottles to add oil to the microscope.
13. Repeat steps 7 & 8. You may need to use the slider under Light Adjustment again for better visualization. Sketch your view of the letter E at 100X in the results area.
14. When you have visualized the Letter E slide using all 4 objective lenses, click on Remove Slide (top right ).
15. Read the notice about using lens paper to clean the immersion oil off the microscope and click on the question mark over the lens paper. Choose wisely!
16. Click on the Main button (bottom left corner) to return to the home page.

 

 

 

QUESTIONS

1.  Sketch the letter “e” at each of the resolutions.  You may print this page and draw directly in the circles or draw on a separate piece of paper, photograph your drawings and upload the image.  Include the magnification level (eg: 40x)
   • Upload here

 

 

 

 

 

 

 

 

 

 

1. 1. 17. What did you notice about the letter E when you increased in magnification from the 4x to the 10x to the 40x?

A:      

 

KNOWLEDGE CHECK

2. Click on the Test button (bottom of home page).  In the challenge mode window, click on Care & Usage and answer all the questions.  If you get a 75% or better, click Choose Test.  If you do not get a 75% or better, click try again.  
   • Screenshot your completed Usage & Care test results and upload here.

 

 

 

3. Next, choose the Calculating Magnification link and repeat step 2 
   • Screenshot your completed Calculating Magnification test results and upload here.

 

 

 

 

 

4. Then choose the Terminology link and repeat #3
   • Screenshot your completed Terminology test results and upload here.