Q. Which of the following are controlled variables for exercise 8.3 ?
A. Distance from the leaf disk to the light source (light intensity).
B. Wattage of light source (light intensity).
C. Depth of bicarbonate solution.
D. Size of leaf disks.
Answer.
All the above parameters are constant throughout the exercise and hence all are controlled variables.
(A) is a controlled variable because the distance of all leaf disks, lying at the bottom of the beaker, is constant from the light source.
(B) The light source (lamp) intensity does not change throughout the experiment.
(C) Depth of bicarbonate solution is kept constant at 5 cm.
(D) Size of leaf disks is uniform since they have been cut using the same hole punch machine.
vided in the notes? Experiment 8.3: Light and Photophosphorylation Now that you have determined which wavelengths...