Question

Curvature in phototropic movements occur:

• A. At the shoot tip
• B. Behind the tip
• C. Away from the tip
• D. At the root tip

Answer 1

The correct option is A At the shoot tip

Charles Darwin discovered that the phototropic bending in the zone of elongation was controlled by the tip. The movements which allow organs of plants to move in or the other directions is called movements of curvature. His demonstration showed that the site of photoreception at the shoot tip and the location of curvature are separable. From his observations, Darwin was able to propose that a transmissible substance produced in the tip is responsible for inducing curvature in lower regions of the plant. This insightful discovery eventually lead to the discovery of first plant hormone produced at the shoot tip - auxin.

Thus, the correct answer is option A.