Name __________________________________
Date ___________________
Osmosis in Plant Cells
Plasmolysis of Elodea
Purpose
The purpose of this lab is to observe the effect of a hypertonic and hypotonic osmotic environment on a plant
cell. The process of cell shrinkage due to a hypertonic environment is knows as plasmolysis.
Materials
Elodea leaves
Tap water
Ten percent salt water
Slides
Coverslips
Microscopes
Droppers
Procedure
1. Place and Elodea leaf on a slide, add a drop of tap water, add a coverslip.
2. Observe the cell under a microscope. The cell membrane is pushed against the cell wall and is not
visible. Note the distribution of chloroplast in the cytoplasm. Set the slide aside.
3. Place a second Elodea leaf on a new slide, add a drop of salt water, and add a cover slip.
Examine.
4. After about 5 minutes, re-examine the cells on each slide and note the distribution of the
chloroplasts.
5. Sketch a view of the cells in each of these environments on your data sheet. Label the cell wall,
cell membrane, chloroplasts, and cytoplasm.
1. Hypothesize what will happen to the Elodea in each of the conditions (tap water, salt water).
2. Would you describe the tap water as a hypertonic, isotonic, or hypotonic solution with respect to
the Elodea? Why?
3. Would you describe the salt water as a hypertonic, isotonic, or hypotonic solution with respect to
the Elodea? Why?
Name __________________________________
Date ___________________
4. Illustrate one cell on the slide of Elodea in tap water. Illustrate one cell on the slide of Elodea in
10 % salt water. Label the cell wall, cell membrane, chloroplasts, and cytoplasm.
Elodea in tap water
400X
Elodea in 10% salt water
400X
5. Did your observations support your hypothesis? Explain why!
6. Would the plant cells burst when exposed to a hypotonic environment? Why or why not?
7. Would you expect an animal cell to burst when exposed to a hypotonic environment?