1. Tropisms: These are directional growth responses to external stimuli. They are typically named for the stimulus they respond to.
* Phototropism: Growth towards light.
* Gravitropism: Growth in response to gravity (roots grow down, shoots grow up).
* Thigmotropism: Growth in response to touch (vines wrapping around a support).
* Hydrotropism: Growth towards water.
* Chemotropism: Growth towards or away from specific chemicals.
2. Nastic Movements: These are non-directional movements in response to stimuli.
* Nyctinasty: Daily opening and closing of flowers or leaves in response to light or darkness.
* Thigmonasty: Movements triggered by touch, like the folding of leaves in the mimosa plant.
* Seismonasty: Rapid movements in response to physical stimulation, like the sudden closure of Venus flytrap leaves.
* Thermonasty: Movements in response to changes in temperature, like the closing of flowers in cold weather.
While these are the two primary categories, plant responses are complex and can involve other factors like hormones and internal clocks.
It's important to note that the division between tropisms and nastic movements isn't always clear-cut. Some responses can be classified as both, depending on the specific circumstances.
