Experiments on the positive phototropic response of plants indicate that
A) light destroys auxin.
B) auxin moves down the plant apoplastically.
C) auxin is synthesized in the area where the stem bends.
D) auxin can move to the shady side of the stem.
E) auxin is only of secondary importance in the process.

Question

Quizplus · Accepted Answer

Experiments have shown that auxin, a plant hormone, is responsible for the positive phototropic response of plants. Auxin accumulates on the shady side of the stem, causing cells to elongate and the stem to bend towards the light source. Therefore, auxin can move to the shady side of the stem, making choice D the correct answer.

Experiments on the Positive Phototropic Response of Plants Indicate That