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Cell Lab
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Purpose: To make observations of plant and animal cells and learn some of the differences and similarities that exist between
them
Part A: Elodea Cells (plant)
1. Remove a young leaf from near the tip of an Elodea plant.
2. Place the leaf in a drop of water in the center of a slide, cover with a cover slip,
and observe under low and high power.
3. Under high power magnification, as the slide begins to warm up, you will see
the chloroplasts and cytoplasm begin to move or stream inside the cell. This
streaming process is known as cyclosis.
4. Answer questions 1-3 before going on.
5. Now add a 5% salt solution to your slide by placing a drop or two at the edge of
the cover slip. This will cause the cell to lose water (dehydrate) and the cell
membrane will shrink away from the cell wall. This shrinking of the cell within
the cell wall is knows as plasmolysis.
6. Answer questions 4-6.
Part B:
1.
2.
3.
Onion Cells (plant)
Carefully remove a very thin layer of onion skin. (The inner side of the skin may be readily peeled.)
Place onion skin in the middle of a slide and add 1 drop of water. Make sure onion skin does not fold over on itself.
To see the nucleus of the cell, you will have to stain the onion skin with iodine. Add one drop of iodine to the onion
skin and cover with a cover slip.
4. Observe using both low and high power.
5. Answer questions 7-11.
Part C:
1.
2.
3.
Cheek Cells (animal)
Gently stroke the inside of your cheek with a toothpick and swirl it in a drop of water on the center of a slide.
Add a small drop of methylene blue to stain the membrane and nucleus and cover with a cover slip.
Answer questions 12-16.
Cell Lab Worksheet
Name
Block
Make all drawings on the back of this paper. Make sure you draw the cells to scale within the field of view circle.
Elodea Cells
1. **Make a drawing of one Elodea cell as you observe it under high power. Label the CELL WALL, CHLOROPLAST, and
CYTOPLASM.
2. Write some general observations about the Elodea cell: shape, color, appearance, etc.
3.
Were you able to see the streaming movement of the cytoplasm? If so, which direction did it flow (clockwise or
counter clockwise)?
4.
5.
**Make another drawing of an Elodea cell after plasmolysis. Label the CELL MEMBRANE, CELL WALL, CHLOROPLAST,
and CYTOPLASM.
What process caused the Elodea cells to shrink? ___________________
6.
Is the salt water solution isotonic, hypertonic, or hypotonic relative to the Elodea cells (circle one)?
Onion Cells
7.
8.
**Draw one onion cell on high power. Label the CELL WALL and NUCLEUS.
Write some general observations about the appearance of the onion cell.
9.
What structures usually found in plant cells are missing from the onion cells? Why?
10. Therefore, what process can’t the onion carry out?
11. What then is the function of an onion to the plant?
Human Cells
12. **Make a drawing of one of your cheek cells on high power. Label the NUCLEUS and CELL MEMBRANE.
13. Write some general observations of this animal cell.
14. What structure previously seen in plant cells are absent from human cells?
15. In what ways are the onion skin cell, the Elodea leaf cell, and the human cheek cell alike and in what ways are they
different?
16. Which type of cell is more box-like and has more clearly defined boundaries.