Question

The closing of leaves of Mimosa plant (lajwanti) when touched is an example of:

• A. Thigmonastic movement
• B. Phototropic movement
• C. Hydrotropic movement
• D. Geotropic movement

Answer 1

The correct option is A

Thigmonastic movement

The closing of leaves of the Mimosa plant (lajwanti), when touched by a finger is an example of thigmonastic movements. Thigmonastic movements are defined as movements by plant parts in response to touch/pressure irrespective of the direction of the stimulus. Another example is Venus fly trap where leaves close rapidly due to touch by an insect.

The movement of plants in response to light is called phototropic movement. Movement of parts of a plant in response to moisture is called hydrotropic movement.

Movement of parts of a plant towards the forces of gravity is called geotropic movement.