Photonasty: It is the non-directional movement of a plant part (e.g. petals of flowers) in response to light. The opening and closing of petals of dandelion flowers in response to light intensity is an example of this process.

Thigmonasty: It is the non-directional movement of a plant part in response to the touch. The folding up of Mimosa pudica leaves when touching is an example of this process.