Name:_________________________ Class:___________ Date:___________
Does that plant need CPR?
Purpose: Do plants breathe? What evidence is there to prove that they do or do
not?
Research and Background:
Hypothesis:
Materials:
2 Clear Cups or Plastic Beakers
Sprigs of Elodea
Bromthymol Blue Solution (BTB)
Straws (with small diamonds cut in the straw)
White Strips of Paper
Safety Goggles
Masking Tape
Procedure:
1. In each cup, fill up to about 3/4 full of water. Allow teacher or lab assistant to
add BTB to the cups.
2. Label your cups with the names of your group members. Label one cup LIGHT and
one cup DARK.
3. Prepare your elodea by removing the bottom few leaves near the stem end.
LIGHTLY crush the stem.
4. “Bubblers” will carefully follow teacher instructions to prepare the BTB solution.
5. Observe the cups and record your findings.
6. Place one elodea stem into one cup, place the cup on the window sill where it can
receive full sun. Place one cup on the tray where it will remain in the dark for 24
hours.
7. Make a second observation with each cup.
8. Place both cups on the window sill in the sunlight for another 24 hours. Record
what you observe a final time.
Predict what you will observe:
Data and Observations:
Light Cup
Beginning of Investigation
24 Hour Point of
Investigation
48 Hour Point of
Investigation
Dark Cup
Results:
Conclusion: