AP BIOLOGY

Detailed explanation-1: -In what ways do plants respond to their environment? Tropisms are growth toward or away from a stimulus. Types of tropisms include gravitropism (gravity), phototropism (light), and thigmotropism (touch).

Detailed explanation-2: -The movement of plant due to touch is known as a thigmotropic movement. Thigmotropism is a directional growth movement which occurs as a mechanosensory response to a touch stimulus. For example, once a shoot touches a suitable support, it grows towards the surface it is touching.

Detailed explanation-3: -Signaling molecules and hormones, including intracellular calcium, reactive oxygen species, octadecanoids and ethylene, have been implicated in touch responses. Remarkably, touch-induced gene expression is widespread; more than 2.5% of Arabidopsis genes are rapidly up-regulated in touch-stimulated plants.

Detailed explanation-4: -sensitive plant, (Mimosa pudica), also called humble plant, plant in the pea family (Fabaceae) that responds to touch and other stimulation by rapidly closing its leaves and drooping.