BIO 111 Lab 2 - Microscopy 1/5
Microscopy Lab Biology LAB 2 (BIO 111)
Complete Solutions - Updated Latest 100%
Name: ____________________________ Date: __________________ Section: __________
Part Requirement Complete Solution / Expected Answer
1 Lab purpose To learn safe handling of the compound light microscope, identify major microscope parts, calculate total
magnification, prepare a wet mount, and record clear observations of cells or microorganisms.
2 Core skill Focus first with the scanning/low-power objective and coarse adjustment. Use fine adjustment only after moving to
high power.
3 Main idea Microscopy makes small specimens visible by using lenses to magnify and resolve detail. The image is
reversed/inverted compared with slide movement.
4 Evidence required A labeled drawing or observation table showing specimen name, objective lens, total magnification, visible
structures, and final interpretation.
Table 1. Microscope Parts and Functions
Microscope Part Function Correct Lab Note
Ocular lens / eyepiece Lens used for viewing; usually 10x. Total magnification = ocular lens x objective lens.
Objective lenses Main magnifying lenses on rotating nosepiece. Typical powers: 4x scanning, 10x low, 40x high.
Stage and clips Hold the slide in place. Center the specimen over the light opening before focusing.
Diaphragm / iris Controls amount of light reaching specimen. More light is usually needed as magnification increases.
Coarse adjustment knob Moves stage/body tube quickly for initial focusing. Use only on scanning/low power to avoid cracking slide.
Fine adjustment knob Small movement for sharp focus. Use on high power for final clarity.
Condenser / light source Directs light through the specimen. Poor illumination can make a prepared slide appear blank.
Prepared for study and exam revision purposes Page 1 of 5
, BIO 111 Lab 2 - Microscope Handling and Calculations 2/5
Pre-Lab Knowledge Check: Complete Solutions
Question Answer Reason
1. Why begin It gives the widest field of view and lowers the A large field makes the specimen easier to locate before magnifying further.
with the risk of damaging the slide.
lowest-power
objective?
2. What The field of view decreases. Higher magnification shows a smaller area in greater detail.
happens to
field of view
as
magnification
increases?
3. What Brightness usually decreases. Less light reaches the eye through the smaller viewing area.
happens to
brightness at
high power?
4. Which Fine adjustment only. Coarse movement may push the objective into the slide.
adjustment
should be
used under
high power?
5. If the The microscope image is reversed/inverted. Compound microscopes reverse image orientation through the lens system.
image
moves left
when the
slide is
pushed right,
what does
this show?
Table 2. Total Magnification Calculations
Ocular Lens Objective Lens Formula Total Magnification
10x 4x scanning 10 x 4 40x
10x 10x low power 10 x 10 100x
10x 40x high power 10 x 40 400x
15x 40x high power 15 x 40 600x
Table 3. Lab Safety and Handling
Situation Correct Action Why This Is Correct
Carrying microscope Use two hands: one on the arm and one under the base. Prevents dropping or tilting the instrument.
Dirty lens Clean only with lens paper. Paper towels or clothing can scratch the glass.
Wet mount has bubbles Lower coverslip at an angle using a needle or forceps. Angled placement pushes air away from the specimen.
Specimen is too dark Increase light or open the diaphragm slightly. More light improves visibility, especially at higher magnification.
Finished observation Return to low power, remove slide, clean stage, wrap cord. Leaves the microscope safe and ready for the next user.
Prepared for study and exam revision purposes Page 2 of 5
Microscopy Lab Biology LAB 2 (BIO 111)
Complete Solutions - Updated Latest 100%
Name: ____________________________ Date: __________________ Section: __________
Part Requirement Complete Solution / Expected Answer
1 Lab purpose To learn safe handling of the compound light microscope, identify major microscope parts, calculate total
magnification, prepare a wet mount, and record clear observations of cells or microorganisms.
2 Core skill Focus first with the scanning/low-power objective and coarse adjustment. Use fine adjustment only after moving to
high power.
3 Main idea Microscopy makes small specimens visible by using lenses to magnify and resolve detail. The image is
reversed/inverted compared with slide movement.
4 Evidence required A labeled drawing or observation table showing specimen name, objective lens, total magnification, visible
structures, and final interpretation.
Table 1. Microscope Parts and Functions
Microscope Part Function Correct Lab Note
Ocular lens / eyepiece Lens used for viewing; usually 10x. Total magnification = ocular lens x objective lens.
Objective lenses Main magnifying lenses on rotating nosepiece. Typical powers: 4x scanning, 10x low, 40x high.
Stage and clips Hold the slide in place. Center the specimen over the light opening before focusing.
Diaphragm / iris Controls amount of light reaching specimen. More light is usually needed as magnification increases.
Coarse adjustment knob Moves stage/body tube quickly for initial focusing. Use only on scanning/low power to avoid cracking slide.
Fine adjustment knob Small movement for sharp focus. Use on high power for final clarity.
Condenser / light source Directs light through the specimen. Poor illumination can make a prepared slide appear blank.
Prepared for study and exam revision purposes Page 1 of 5
, BIO 111 Lab 2 - Microscope Handling and Calculations 2/5
Pre-Lab Knowledge Check: Complete Solutions
Question Answer Reason
1. Why begin It gives the widest field of view and lowers the A large field makes the specimen easier to locate before magnifying further.
with the risk of damaging the slide.
lowest-power
objective?
2. What The field of view decreases. Higher magnification shows a smaller area in greater detail.
happens to
field of view
as
magnification
increases?
3. What Brightness usually decreases. Less light reaches the eye through the smaller viewing area.
happens to
brightness at
high power?
4. Which Fine adjustment only. Coarse movement may push the objective into the slide.
adjustment
should be
used under
high power?
5. If the The microscope image is reversed/inverted. Compound microscopes reverse image orientation through the lens system.
image
moves left
when the
slide is
pushed right,
what does
this show?
Table 2. Total Magnification Calculations
Ocular Lens Objective Lens Formula Total Magnification
10x 4x scanning 10 x 4 40x
10x 10x low power 10 x 10 100x
10x 40x high power 10 x 40 400x
15x 40x high power 15 x 40 600x
Table 3. Lab Safety and Handling
Situation Correct Action Why This Is Correct
Carrying microscope Use two hands: one on the arm and one under the base. Prevents dropping or tilting the instrument.
Dirty lens Clean only with lens paper. Paper towels or clothing can scratch the glass.
Wet mount has bubbles Lower coverslip at an angle using a needle or forceps. Angled placement pushes air away from the specimen.
Specimen is too dark Increase light or open the diaphragm slightly. More light improves visibility, especially at higher magnification.
Finished observation Return to low power, remove slide, clean stage, wrap cord. Leaves the microscope safe and ready for the next user.
Prepared for study and exam revision purposes Page 2 of 5
