Parts, Descriptions, and Functions of a Compound Light Microscope
Part I – Identification : Write the correct microscope part being described.
1. A small cylinder attached to the upper part of the body tube that holds the ocular lens.
2. Moves the body tube or stage up and down in large increments to bring the specimen
into rough focus.
3. Moves the body tube or stage in very small increments for sharp focusing, especially in
high power.
4. The circular part that connects and rotates the objective lenses.
5. A detachable cylinder located on top of the draw tube that magnifies the specimen
10×.
6. The platform that supports the specimen slide and allows light to pass through.
7. Used to secure the slide on the stage.
8. The joint that connects the arm and pillar, allowing the microscope to tilt.
9. The part that provides firm support to the entire microscope.
10. Found below the stage; reflects and directs light upward through the specimen.
Part II – Multiple Choice (2 points each): Choose the correct answer and write the letter
only.
1. Which part of the microscope connects the ocular lens to the revolving nosepiece?
a. Draw tube b. Body tube c. Arm d. Pillar
2. Which knob should be used when focusing with the high-power objective lens?
a. Coarse adjustment knob b. Fine adjustment knob c. Inclination joint d. Stage
clips
3. What is the correct order of objective lenses when increasing magnification?
a. Scanner → HPO → LPO b. OIO → LPO → HPO
c. Scanner → LPO → HPO → OIO d. LPO → Scanner → OIO
4. Which part is responsible for adjusting how much light passes through the specimen?
a. Mirror b. Condenser c. Iris diaphragm d. Revolving nosepiece
5. This part supports the microscope when carried:
a. Base b. Arm c. Pillar d. Stage
6. Which part concentrates light onto the specimen?
a. Condenser b. Iris diaphragm c. Mirror d. Stage
7. The correct position of the microscope when being carried is:
a. Hold by the stage and nosepiece
b. Hold by the arm and base
c. Hold by the body tube only
d. Hold by the fine adjustment knob
8. What part connects the base and the arm together?
a. Inclination joint b. Pillar c. Stage d. Condenser
9. Which part of the microscope usually has a black pointer line?
a. Ocular lens b. Objective lens c. Stage d. Iris diaphragm
10. Which part allows the user to change from low power to high power magnification?
a. Arm b. Revolving nosepiece c. Coarse adjustment knob d. Base
Part III – True or False (1 point each) :Write T if the statement is true and F if false.
1. The fine adjustment knob should be used first before the coarse adjustment knob.
2. The mirror is located above the stage.
3. The condenser helps focus light on the specimen.
4. The base of the microscope should always rest on the table.
5. The objective lens is used to view the specimen with 10× magnification.
6. The pillar provides support to the upper parts of the microscope.
7. The stage has a hole that allows light to pass through the specimen.
8. The iris diaphragm is used to increase or decrease brightness.
9. The ocular lens and the body tube are part of the illuminating system.
10. The coarse adjustment knob moves the body tube in larger increments.
Part IV – Short Answer (3 points each): Answer briefly and clearly.
1. Differentiate between the mechanical, magnifying, and illuminating parts of a
microscope.
2. Why is it important to start focusing a specimen using the low-power objective lens
first?
3. What would happen if you used the coarse adjustment knob while under high-power
objective?
4. Explain how light travels through the microscope—from the light source to the eyes.
5. Why must the slide be secured tightly with stage clips during observation?
