Mariah Adams
BIOL122-Fall 2013
Ancilla College
1
Osmolarity of Plant Cells
INTRODUCTION
1. Students will investigate the osmolarity of living tissues using plant cells as a model.
2. Using sections of apples, students with test the osmolarity point of plant tissues.
3. After performing the required tasks, students will calculate the approximate concentration of
solutes in the cytoplasm of the apple cells in this experiment.
HYPOTHESIS
1.
2. I predict that the apple with shrink in 10%, 5%, and 2% sodium chloride. I believe in
1% sodium chloride the apple with remain unchanged. I predict the apple with start to
swell in .5% and .2% sodium chloride. I predict the apple will stay the same in distilled
water.
BACKGROUND
METHODS AND MATERIALS
MATERIALS
For this experiment, we will need the following items:
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Fresh apple
4mm diameter cork borer
Small ruler
Forceps
7 small test tubes
Test tube rack
Marker
A gradient of salt solutions in containers with large droppers:
1. 10% sodium chloride
2. 5% sodium chloride
3. 2% sodium chloride
4. 1% sodium chloride
Mariah Adams
BIOL122-Fall 2013
Ancilla College
2
5. 0.5% sodium chloride
6. 0.2% sodium chloride
7. Distilled Water
METHODS
For this experiment, we cut 4mm squares from the fresh apple. We carefully measured
each square before the experiment begun. After we set up and labeled each test tube
with the solution it was supposed to have, we added 5 mL of each solution to the test
tube. We then placed an apple square into each of the test tubes. After 15 minutes, we
removed the apple squares from each test tube then promptly measured the size of
each square.
ANALYSIS
DATA
Size of Apples
Before
After
1 x .5 x .5
.9 x .7 x .6
.7 x.5 x .6
.9 x .7 x .6
1 x .5 x .7
.9 x .7 x .5
1 x 1 x .4
.9 x .6 x .5
.7 x .5 x .7
1 x .7 x .6
.7 x .6 x .6
1 x .6 x .6
.7 x .9 x .6
.7 x .9 x .6