Question

Explain nastic movements. [3 MARKS]

Answer 1

Each point: 1 Mark

1. The movement of a plant part in response to an external stimulus in which the direction of response is not determined by the direction of stimulus is called nastic movement.
2. For example - folding of leaves of a sensitive plant (Mimosa pudica) on touching it.
3. Here the stimulus is touch. Hence this type of movement is called thigmonastic movement.