Plants growing in a partially dark environment will grow toward light in a response called phototropism. Which of the following statements is true regarding phototropism?
A) It is caused by an electrical signal. B) One chemical involved is ethylene. C) Auxin causes a growth increase on one side of the stem. D) Auxin causes a decrease in growth on the side of the stem exposed to light. E) Removing the apical meristem enhances phototropism.
According to modern ideas about phototropism in plants,
A) light causes auxin to accumulate on the shaded side of a plant stem. B) auxin indirectly inhibits elongation of plant stem cells. C) auxin is produced by the apical meristem of the coleoptile and moves downward. D) all hormones move downward via the xylem. E) cytokinins are more directly involved than auxins.