Microscopes

Microscopes

What is this?

I. Parts of the Compound Light Microscope

Metal or plastic part on which microscope rests

BASE

Somewhat C-shaped pillar arising from the base and supports the stage

and ocular components. Used for carrying

ARM

Flat platform attached to lower portion of arm on which slides or

samples are

STAGE

Collects light rays and focuses them on the specimen slide. Can be adjusted for better resolution

(sharper image)DIAPHRAGM

Convex lens used to magnify the image; generally 10-15x

magnification

Ocular or eyepiece

Small convex lenses screwed into nosepiece and increase the magnification of the sample.

Low power = 4x

high power =40x

OBJECTIVES

Larger knob which moves the base rapidly up or down to get the sample into coarse

focus

COARSE ADJUSTMENT KNOB

Smaller knob which moves the base slowly through short distances to get the sample

into sharp focus

FINE ADJUSTMENT KNOB

REMEMBER:All specimens must be thin for LIGHT to shine

through them so that you can see clearly.

REMEMBEROnly use the FINE ADJUSTMENT

KNOB when focusing on medium or high power objectives!!This avoids damaging or

breaking the slide

Electron microscopeElectron microscope – a

microscope that focuses beams of electrons instead of light rays. Produces clearer, 3D images.

Muscle Tissue!

LIGHT MICROSCOPE VS. ELECTRON MICROSCOPE

Calculating magnificationJust multiply the objective lens power by the

ocular lens powerLower power: 10 X 4= 40Medium power: 10 x10= 100High power: 10x40=400

Guided Practice• Instructions:

You will be using your fingers to show me the correct answer for the following questions

We are going to read the question SILENTLY. DO NOT CALL OUT THE ANSWER.

Think about the question and pick an answer.

When I count to 3, You are going to hold up your choice.

DO NOT LOOK AT ANYONE ELSE’S ANSWER!! THIS IS YOUR TIME TO FIGURE OUT IF YOU KNOW THE INFORMATION!

QUESTION 11. One advantage of using a light microscope is

that it –

A. has high resolution

B. magnifies clearly to 1000x

C. can be used to view living cells

D. can be used to view atoms

QUESTION 11. One advantage of using a light microscope is

that it –


B. magnifies clearly to 1000x

C. can be used to view living cells


QUESTION 22. When you are focusing on medium or high

power objectives, you should use the

A.Coarse knob adjustment

B.Fine knob adjustment

C.Ocular

D.Diaphargm

QUESTION 22. When you are focusing on medium or high

power objectives, you should use the

A.Coarse knob adjustment

B.Fine knob adjustment

C.Ocular

D.Diaphargm

Question 3The purpose of the diaphragm is to

A.Adjust the amount of light focusing on the specimen

B.Magnify the specimen on the stage

C.Adjust the magnification of the specimen

D.View the specimen on the stage

Question 3The purpose of the diaphragm is to

A.Adjust the amount of light focusing on the specimen

B.Magnify the specimen on the stage

C.Adjust the magnification of the specimen

D.View the specimen on the stage

Question 4If a microscope’s ocular is marked 10x and the low

power objective is marked 4x, what would be the total magnification when using the low power objective?

A. 10x C. 40x

B. 12x D. 400x



A. 10x C. 40x

B. 12x D. 400x



A. 3x

B. 300x

C. 30x

D. 3000x



A. 3x

B. 300x

C. 30x

D. 3000x

Question 6 One disadvantage of using an electron

microscope is that it


B. Very expensive

C. shows details of the surface


Question 6 One disadvantage of using an electron

microscope is that it


B. Very expensive

C. shows details of the surface


Worktime1. How should you carry a microscope?

2. What knob should you use to focus when using a high power objective?

3. Why should you not use the coarse knob adjustment when using the high power objective?




4.What is the purpose of the diaphragm?

5.Where is the ocular lens located?

6.Where are the objective lens located

7.What is the purpose of the stage?8. If the ocular lens has a magnification of 10x and the objective lens has a

magnification of 25x, what is the total magnification?

9. If the ocular lens has a magnification of 4x and the objective lens has a magnification of 50x, what is the total magnification?





4. What is the purpose of the diaphragm?

5. Where is the ocular lens located?

6. Where are the objective lens located

7. What is the purpose of the stage?



10.If the ocular lens has a magnification of 5x and the objective lens has a magnification of 100x, what is the total magnification?

Exit Ticket:11) I used to work at an Air force base. We would

work with particles of metal called nano particles. The particles were dead, and microscopic. What would be the best way to see those?

a) A light microscopeb) An electron scanning microscopec) A light telescoped) An electron scanning teloscope

Exit Ticket 2:2) When the low power objective is being used you

should adjust it using the:

a) fine adjustment knob

b) diaphragm

c) course adjustment knob

d) ocular adjustment knob

Exit Ticket 33) Which of the following statements is NOT true

about objects viewed with an electron scanning microscope?

A. They must be thin enough to allow light to pass through them.

B. They must be living specimens

C. No dyes or states can be used on the objects

D. They must be made of organic material

Exit Ticket 44) If the microscopes ocular lens is marked 10x

and the lower power objective is marked 5x, what is the total magnification?

a) 10

b) 5

c) 50

d) 500

Exit Ticket: 55) What is the proper way to place a cover slip on

a wet mount slide?

a) c)

b) d)

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Microscopes