Chapter 2.2: Use of microscope Flashcards
1
Q
State the function of the eyepiece and objective lens
A
Magnify specimen
2
Q
State the function of the coarse adjustment knob
A
Raise or lower body tube (or stage) for rough focusing
3
Q
State the function of the fine adjustment knob
A
- Move body tube slightly to produce more accurate focus
2. Avoid crushing objective lens to slide
4
Q
State the function of the condenser
A
Concentrates light reflected from mirror onto specimen
5
Q
State the function of the iris diaphragm
A
Regulates amount of light passing through condenser
6
Q
State the examination steps of the microscope in low-power
A
- Select low power eyepiece and objective
- Adjust mirror to reflect light through hole on stage
- Adjust condenser and iris diaphragm to pass more light through specimen
- Focus with coarse and then fine adjustment knob
7
Q
State the examination steps of the microscope in high-power
A
- Locates it to centre of field of view
- Rotate the nosepiece to select high power objective
- Adjust condenser and iris diaphragm to pass more light through specimen
- Focus with fine adjustment knob
8
Q
Diiferences between low and high power magnificaton
A
1. Size of image Smaller Larger 2. Brightness of image Brighter Dimmer 3. Details of specimen Less More 4.Field of view Larger Smaller 5. No. of cells More Less
9
Q
State the precautions of using light microscope
A
- Use low power objective first then locate part of specimen to observe more easily
- Never move body tube downwards when looking through eyepiece to prevent break slide and damage objective
