Question
Describe different types of nastic movements with one example from each.
Answer
Nastic movements are non-directional movements in plants that occur in response to a stimulus, and their direction is independent of the direction of the stimulus. There are different types of nastic movements, which are described below along with one example from each:
- Seismonastic Movements: These are rapid movements that occur in response to mechanical stimuli, such as touch or vibrations. Example: The closing of leaves of the sensitive plant (Mimosa pudica) in response to touch or disturbance.
- Thermonastic Movements: These are movements that occur in response to temperature changes. Example: The opening of the flowers of certain plants, such as the evening primrose (Oenothera biennis), in response to a drop in temperature.
- Photonastic Movements: These are movements that occur in response to changes in light intensity. Example: The opening and closing of petals in response to changes in light intensity, as seen in the flowers of the tulip (Tulipa spp.).
- Nyctinastic Movements: These are movements that occur in response to changes in the day-night cycle. Example: The opening and closing of flowers and leaves of certain plants, such as the morning glory (Ipomoea spp.), in response to changes in light and dark periods.
