Tropic movements
1. These movements are always in the direction of the stimulus.
2. These movements are slow.
3. These movements are exhibited by all parts of a plant. For example, movement of shoot towards the light and not towards gravity.
Nastic movements
1. These movements are neither away nor towards the stimulus.
2. These movements are fast.
3. These movements are exhibited by the flat organs (like leaves and petals of flowers) of a plant. For example, the bending and drooping of leaves in ‘Touch-me-not’ plant.