After some time,the tip of a plant that has been forced into a horizontal position grows upward.This phenomenon is related to
A)calcium release from the endoplasmic reticulum of shaded cells.
B)whether the plant is in the northern or southern hemisphere.
C)auxin production in cells receiving red light.
D)auxin movement toward the lower side of the stem.

Question

Quizplus · Accepted Answer

The phenomenon described is known as gravitropism, and it is caused by the movement of the plant hormone auxin towards the lower side of the stem when the plant is placed horizontally. This causes cell elongation on the lower side, causing the stem to eventually grow upwards. Therefore, choice D, auxin movement toward the lower side of the stem, is the correct answer.

After Some Time,the Tip of a Plant That Has Been