Question

Consider the following phenomena and which of them is a tropic movement?

1. The closing of leaves by touch-me-not plant.
2. The growth of a plant towards the light.

• A. Only 1
• B. Only 2
• C. Both 1 & 2
• D. Neither 1 nor 2

Answer 1

The correct option is B

Only 2

Movement in touch-me-not plant is a non-directional movement or nastic movement. The response is independent of the direction of the stimulus. Growth towards light, gravity and water are directional movements or tropic movement i.e., either towards or away from the stimulus.