In the late 1870s Charles Darwin and his son Francis discovered that if the tip of the grass was covered,phototropism did not occur,even though the rest of the grass was exposed to light.However,if the rest of the plant was covered and only the tip exposed to light the grass bent a few centimeters below the tip.Which of the following was sensing the light?

Question

Quizplus · Accepted Answer

The experiment conducted by Charles Darwin and his son Francis suggests that the tip of the grass played a crucial role in sensing the light, as phototropism did not occur when the tip was covered. Therefore, the auxin-producing cells in the tip of the grass (choice A) are the ones responsible for sensing the light, while the auxin detecting cells in the tip of the grass (choice B) or the auxin-producing or detecting cells a few centimeters below the tip of the grass (choices C and D) would not have been directly exposed to the light source.

In the Late 1870s Charles Darwin and His Son Francis