Date: ____________________
SBI 3C
Name: ____________________
PLANT & ANIMAL CELL LAB
PRELAB:
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Study:
o how to use a microscope
o how to prepare a wet mount
o how to draw biological drawings
Review procedure for this lab
Prepare biological diagram sheets for both cells
PURPOSE: To examine the structures of actual plant and animal cells.
To compare cell structures seen using the light microscope to structures in the textbook.
MATERIALS: Onion bulb, Microscope, cover slips, slides, water, droppers, stains, toothpicks and
petridis.
METHODS:
Preparing Plant Cell (Onion) Wet Mount
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Obtain a slide and cover slip. Clean with lens paper if necessary.
Obtain onion tissue by peeling off the skin.
Prepare the wet mount using the procedure in your notes.
Place wet mount on the stage of the microscope.
Observe the onion tissue with the microscope using the procedure in your notes.
Draw a biological drawing of the onion tissue. Label all the structures you see.
Complete all magnification calculations of the biological drawing.
Clean the slide and cover slip with water. Dispose onion tissue in garbage can.
Return all materials and clean up lab station.
Preparing Animal Cell (Cheek) Wet Mount
1. Obtain a slide and cover slip. Clean with lens paper if necessary.
2. Obtain cheek tissue by scratching the inside of your mouth (cheek area) with a
toothpick.
3. Prepare the wet mount using the procedure in your notes.
4. Place wet mount on the stage of the microscope.
5. Observe the cheek cells with the microscope using the procedure in your notes.
6. Draw a biological drawing of the cheek cells. Label all the structures you see.
7. Complete all magnification calculations of the biological drawing.
8. Clean the slide and cover slip with water.
9. Return all materials and clean up lab station.
OBSERVATIONS:
Onion Cells
Cheek cells
ANALYSIS:
1.) Onion cell-
It is assumed that the diameter of low power field of view for the microscope that was used
is 4000µm.It is also assumed that the diagram shown for onion cells are observed in
medium power of the microscope. The possible calculations for medium power as
40×100X =? /4000 µm
Diameter of medium power field of view =1600 µm
Estimated number of times in which onion cell would fit under field of view =2
Size of onion cell-1600/2=800 µm
Assumed length of biological diagram12cm=120000 µm
Magnification of onion cell =length of diagram/size of cell
120000 µm /800120000 µm=150
Therefore, diagram is150 times magnified than the actual cell.
Cheek Cell
It is assumed that the diameter of low power field of view for the microscope that was used
is 4000µm.It is also assumed that the diagram shown for cheek cells are observed in
medium power of the microscope. The possible calculations for medium power as
40×100X =? /4000 µm
Diameter of medium power field of view =1600 µm
Estimated number of times in which cheek cell would fit under field of view =3
Size of cheek cell-1600/3=534 µm
Assumed length of biological diagram12cm=120000 µm
Magnification of cheek cells =length of diagram/size of cell
120000 µm /534 µm=225
Therefore, diagram is 225 times magnified than the actual cell.
2.) The biological diagrams in the textbook are more organized but here only cell wall or
membrane, and nucleus visible. Different organelles are clearly marked in book but not
visible under the microscope.
PrecautionsProperly follow all the steps of procedure.
Gently scraping the inner surface of cheeks with toothpicks and do not hurt your cheeks.
Carefully put the cover slip on slide and avoid the bubbles under the cover slip.
Do not get material dry.
Handle the microscope carefully.
Clean and set the mirror of microscope before using it.