Tropism | Tropic Movements of Plants | Biology | Control and Coordination
Tropisms are usually named for the stimulus involved (for example, a phototropism is a reaction to light) and may be either positive (towards the stimulus) or negative (away from the stimulus).
Four Types of Tropism -
1. Phototropism: It is the Directional Movement or Orientation of the Plant Part.in response to Light Stimulus. If the Plant Part Moves Towards the Light it is Called Positive Phototropism
If the Plant Part Moves away from the Light it is Called Negative Phototropism
2. Geotropism: It is the Directional Movement or Orientation of the Plant Part in Response to Gravity. If the Plant Part Moves Towards the Gravity it is Called Positive Geotropism
If the Plant Part Moves Against the Gravity it is Called Negative Phototropism
3.Chemotropism: It is the Directional Movement or Orientation of the Plant Part in Response to a chemical stimulus. If the Plant Part Moves Towards the chemical Stimulus, it is Called Positive Chemotropism. If the Plant Part Moves against the chemical Stimulus, it is Called Negative Chemotropism.
4.Hydrotropism: It is the Directional Movement or Orientation of the Plant Part in Response to Water Stimulus. If the Plant Part Moves Towards the Water Stimulus, it is Called Positive Hydrotropism. If the Plant Part Moves away from the Water Stimulus, it is Called Negative Hydrotropism.