Lab #5 Questions/Data sheet Name: ______

You will record you data and answers to the questions on the following data sheet.

Questions from the Prelab:

  1. Why do plant cells do cellular respiration? (e.g., what does cellular respiration produce?)
  2. Why do plant cells photosynthesize (e.g., what does photosynthesis produce?)
  3. Which processes (cellular respiration/photosynthesis/both) occur in the dark?
  4. Which processes (cellular respiration/photosynthesis/both) occur under light conditions?
  5. Where do the products of photosynthesis go?
  6. Given your answer to question #5, which should be faster, the rate of photosynthesis or the rate of cellular respiration and why?
  1. Given you answer to questions #4 & #6, what do you predict will happen to the O2 under light conditions and why?

DATA

Table 1: Data from cellular respiration/photosynthesis experiment with Elodea
experimental treatment / weight (g) / starting O2 / ending O2 / O2 / Corrected O2/g
“Light”
“Dark”
Table 2. CorrectedO2/g from each class groups and average corrected O2/g.
Corrected O2/g
Condition / Group 1 / Group 2 / Group 3 / Group 4 / Group 5 / Group 6 / Group 7 / Group 8 / Average

Elodea-Light

Elodea-Dark

You may need to revise your initial hypotheses after discussion with your group.

Table 3.Dark Conditions. Hypothesis table about whether cellular respiration rate or photosynthetic rate is greater in the “Dark” conditions.

Hypothesis:
Prediction:
Reasoning (what are the concepts/knowledge you are basing your hypothesis & prediction on?):
Interpretation (circle one): support or reject?
Reasoning (for your choice of "support" or "reject")
If rejected, a corrected hypothesis:

Table 4. Light Conditions (Hypothesis table about whether cellular respiration rate or photosynthetic rate is greater in the “Light” conditions.)

Hypothesis:
Prediction:
Reasoning (what are the concepts/knowledge you are basing your hypothesis & prediction on?):
Interpretation (circle one): support or reject?
Reasoning (for your choice of "support" or "reject")
If rejected, a corrected hypothesis:

Additional Questions:

  1. Calculate what the corrected O2/g would have been if we could have kept the plant from doing cellular respiration in the “light” conditions (i.e., in the absence of cellular respiration, so that the plant was only photosynthesizing).
  1. Why do we divide O2 by the weight of the organism?