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

Auxin-producing cells in the tip of the grass are sensing the light and causing the phototropic response. When the tip of the grass is covered, no auxin is being produced, and therefore, the phototropic response does not occur. When the rest of the plant is covered and only the tip is exposed, the auxin produced in the tip is detected by cells a few centimeters below the tip, causing the bending response.

In the Late 1870s,Charles Darwin and His Son Francis Discovered