SBI4UName: ______
Investigating Cells Activity
In this activity you will be preparing wet mount slides of potato and tomato cells, and looking at a prepared wet mount slide of cheek cells.
Preparing a wet mount slide:
Materials: clean toothpick, tweezers, slide, cover slip, beaker with distilled water,
medicine dropper, paper towel
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1. Obtain a sample of cells..
2. Add a drop of water to the centre of the slide. Place the sample of cells in the water drop.
3. Gently add the cover slip by holding it at a 45º angle at the edge of the drop, and slowly lowering it
over the specimen.
4. Remove excess water using paper towel, and observe under a light microscope.
Staining a wet mount slide:
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1. Remove the slide from the microscope, place it on a paper towel.
2. Place one drop of the stain (e.g., methylene blue) to one side of the cover slip.
3. Place a small piece of paper towel at the opposite side of the cover slip, as shown in the image
above. The paper towel will draw the dye from the other edge of the cover slip.
Biological Drawings Tips:
•Use blank paper and pencil and at least 1/3 to 1/2 of a page for each drawing.
•Draw using solid lines, do not sketch.
•Use dots or stippling to indicate darker areas, do not shade.
•Labels should be to the same side (usually right) of the diagram and printed in lowercase letters.
Label lines should be straight and should not cross.
•Title should be in capital letters and centered above the drawing.
•Magnification should be indicated (usually at the bottom right).
Part I: Eukaryotic Cells - Animal Cells
1. Examine the wet mount of cheek cells under the microscope using high power magnification.
2. Carefully draw several cells as they appear under the microscope and label the cytoplasm,
nucleus, and plasma membrane.
3. Estimate the size of a typical cell, and show your calculation and estimate beside or at the bottom
of your drawing.
Part II: Eukaryotic Cells - Potato Cells (Amyloplasts)
Plastids are free-floating, membranous organelles found only in plant cells. They either store materials that are useful to the plant cell or perform important functions that keep the cell alive. Amyloplasts are white or colourless plastids that store the energy-rich products of photosynthesis in the form of starch.
1. Prepare a wet mount of a small piece of potato.
2. Examine the potato wet mount under the microscope and locate the amyloplasts.
3. Remove the slide from the microscope and stain it carefully with Lugol's (iodine)solution. Wait
one minute and then examine the slide under the microscope again.
4. Carefully draw several cells as they appear under high power (or medium power if high isn't
possible) under the microscope Label the cytoplasm, plasma membrane, and amyloplasts.
5. Estimate the size of a typical cell, and show your calculation and estimate beside or at the bottom
of your drawing.
Part III: Eukaryotic Cells - Tomato Cells (Chromoplasts)
Chromoplasts are colourful plastids containing the red, orange, and yellow pigments commonly found in flowers, fruits, and vegetables.
1. Using a toothpick, carefully scrape some tomato pericarp (tissue just under the peel).
2. Prepare a wet mount of the tomato using a drop of methylene blue in addition to the drop of water.
Using the toothpick, lightly spread the pericarp through the liquid before covering with the cover
slip.
3. Examine the tomato wet mount under the microscope and locate the chromoplasts.
4. Carefully draw several cells as they appear under high power (or medium power if high isn't
possible) under the microscope Label the cytoplasm, plasma membrane, and chromoplasts.
5. Estimate the size of a typical cell, and show your calculation and estimate beside or at the bottom
of your drawing.