Microscope

Question 1

What is the eyepiece?

Answer 1

It’s the piece that you look through (magnifies the object 10x)

Question 2

What is the body tube?

Answer 2

Made up of the eyepiece and objective lenses

Question 3

What is the arm?

Answer 3

Connects the base to the body.

Question 4

What is the stage?

Answer 4

Holds the slide

Question 5

What is the coarse adjustment knob ?

Answer 5

It brings the image into fine focus.

Question 6

What is the fine adjustment knob?

Answer 6

Used after the coarse adjustment Knob, it brings the object into fine focus.

Question 7

What does the lamp or mirror do?

Answer 7

Illuminates the specimen

Question 8

What is the revolving nosepiece?

Answer 8

Holds the objective lenses. It rotates so that you can use different lenses.

Question 9

What is the diaphragm?

Answer 9

Directs the light towards the specimen

Question 10

What is the base?

Answer 10

The base supports the microscope.

Question 11

What is the formula to calculate the size of an object under the microscope?

Answer 11

Size of object = Diameter of field of view
————————-
Number of objects that fit across the diameter of field of view

Question 12

How do you calculate total Magnification ?

Answer 12

Ocular lens Magnification x objective lens Magnification

Question 13

What is the Magnification of the objective lenses?

Answer 13

Low - 4x
Medium - 10x
High - 40x

Question 14

What is the diameter view under each of the objective lenses ?

Answer 14

Low - 4000 micrometers
Medium - 1500 micrometers
High - 400 micrometers

Question 15

Explain an important thing to remember as you turn the high power objective lens into place.

Answer 15

Do not use the coarse adjustment knob under high power

Question 16

What should you always remember when you use the coarse adjustment?

Answer 16

Only use the coarse adjustment under low power. Otherwise you risk cracking your objective lens or your slide.

Question 17

Under what conditions would you adjust the diaphragm?

Answer 17

You would adjust the diaphragm if there was not enough light coming through for you to see your specimen clearly.

Question 18

Explain the process to find a specimen under high power.

Answer 18

1. Be sure the stage is lowered all the way down.
2. Turn the light source on.
3. Turn the revolving nosepiece so that the lowest power objective lens is clicked into position.
4. Place the microscope slide on the stage and fasten it with the stage clips.
5. Look at the objective lens and the stage from the side and turn the course focus knob so the stage moves upward. Move it up as far as it will go without letting the objective touch the coverslip.
6. Look through the eyepiece and move the course focus knob until the image comes into focus.
7. Adjust the diaphragm and light intensity for the greatest amount of light.
8. Move the microscope slide around until the sample is in the centre of the field of view (what you see).
9. Use the fine focus knob to bring the object into fine focus.
10. When you have a clear image of your sample with the lowest power objective, you can change to the next objective lens. You have to place the pointer directly on the part of the slide you want to magnify using the next objective lens.
11. Turn the revolving nosepiece so the medium power objective lens is in place.
12. Use only the fine focus knob to focus on your specimen.
13. When you have a clear image of your sample with the medium power objective, you can change to the next objective lens. You have to place the pointer directly on the part of the slide you want to magnify using the next objective lens.
14. Turn the revolving nosepiece so the high power objective lens is in place.
15. Use only the fine focus knob to focus on your specimen.
16. When finished, lower the stage, click the low power lens into position and remove the slide.

Question 19

How is a wet mount made?

Answer 19

1. Place the specimen on the slide
2. Using the eye dropper place one drop of water on top of the specimen.
3. Place the cover slip at a 45 degree angle (approximately) with one edge touching the water drop, and let go.
4. If there are any air bubbles under the cover slip, use the eraser end of a pencil to tap them out
5. Using a bit of paper towel, blot any excess water

Question 20

What should you always remember when handling microscope slides ?

Answer 20

To be careful not to break them with the lens or to drop them. Also do not touch the slide because you will get fingerprints on the slide and you won’t be able to see your specimen clearly.

Question 21

What is the purpose of stage clips?

Answer 21

Holds the slide in place on the stage

Question 22

What is the purpose of the coverslip?

Answer 22

To cover the specimen

Question 23

What are the chemicals called that are sometimes used to make the specimens visible?

Answer 23

Stains

Question 24

What should you do if the high power objective lens touches or breaks the coverslip?

Answer 24

Tell the teacher and replace it.

Question 25

Why do you need the specimen to be a thin sample rather than a thick one when you create a wet or dry mount?

Answer 25

If the specimen is too thick the light won’t come through the specimen and you won’t be able to see it.

Question 26

How do you make a dry mount?

Answer 26

To make a dry mount simply place the specimen on a dry slide and cover with a cover slip. No water is necessary.