Tropic movements are direction dependent movements that occur in plants in response to external stimulus. Types of tropic movements are-
1. Geotropism is the growth or movement in response to gravity, such as roots grow towards gravity.
2. Phototropism is the growth or movement towards the light, such as sunflower bends towards the sunlight.
3. Chemotropism is the growth or movement in response to some chemicals, such as pollen tube move towards the ovule for fertilisation.
4. Hydrotropism is the growth or movement in response to water, such as bending of roots towards more water.