Microscope Skills Worksheet Year 11 Biology

1. How does altering the iris diaphragm work to affect the light. How is this similar to how the iris in your eye works? (4)

2. What happens to the appearance of an air bubble when you focus up and down? Why? (3)

3. If you cut out a letter “e” and made a wet mount of this and examined it under a microscope what would it look like? Why? (2)

4. What does the word “Parfocal” mean when applied to a microscope? (2)

5. If you move the slide that you are looking at left and down what way does the image move? Why? (2)

6. Why must you be careful when using the revolving nose piece? Why? (2)

7. What happens to the level of illumination when you change to a higher power? How can you compensate for this? (2)

8. How do you calculate the total magnification setting of your microscope? What is the maximum and what is the minimum power of your microscope? (3)

9. What happens to the resolution of your microscope as the magnification is increased? (2)

10. When focusing on objects under the microscope why should you focus by moving the lens away from the slide.? (2)

11. What unit of measure do we use for microscope work? Explain why this is better than using millimeters? (4)

12. What is “the working distance”? When is it the greatest and when is it the least?(3)

13. Why are stains sometimes used when preparing cell tissue for examination with the microscope? (3)

14. Explain how the size of cells, length and width is estimated at 400x magnification.

15. Using a diagram(s) explain how to prepare wet mount of a specimen, (5)

16. Write a paragraph to explain to a new student the best way to go about seeing a good image of a slide of an onion tissue you had prepared at 400x magnification.

(5)