* Thigmotropism is the growth of a plant in response to touch or contact. Vines use tendrils or other specialized structures to sense and wrap around objects, like posts. This allows them to climb and reach for sunlight.
* Gravitropism is the growth of a plant in response to gravity. While roots exhibit gravitropism (growing downwards), a vine wrapping around a post isn't primarily driven by gravity.
The vine's ability to sense the post and wrap around it is a classic example of thigmotropism.
