Question
Distinguish between Tactic and Nastic movements.
Answer
| Tactic Movements | Nastic Movements |
|---|---|
| Movement in response to a directional stimulus | Movement in response to a non-directional stimulus |
| The movement towards or away from a stimulus | Movement in any direction |
| Phototaxis (movement in response to light) and geotaxis (movement in response to gravity) | Thigmotropism (response to touch), hydrotropism (response to water), and chemotaxis (response to chemicals) |
| Positive (towards the stimulus) and negative (away from the stimulus) | Non-directional, can be classified as growth movements (e.g. thigmotropism) or response movements (e.g. nyctinasty) |
