NEET BIOLOGY

Detailed explanation-1: -Some common plant stimuli include light, gravity, water, movement of the sun, and touch. The naming of the tropism is associated with the stimulus. For example, the movement of plant roots towards water is called hydrotropism.

Detailed explanation-2: -Light, water and touch are all examples of stimuli. The closing of leaves and bending of shoots are responses to stimuli.

Detailed explanation-3: -Phototropism, a reaction to light, causes the plant to bend toward the light source (see Essential Processes, Auxins). Thigmotropism, a reaction to touch, causes parts of the plant to thicken or coil as they touch or are touched by environmental entities.

Detailed explanation-4: -Thigmotropism is a plant’s response to touch. Stems of many vines show positive thigmotropism when they encounter something and wrap themselves around it. Hydrotropism is plants’ growth in response to water.