AP BIOLOGY

Detailed explanation-1: -Hydrotropism is the movement of plant parts in response to water. Thus, the stimulus for hydrotropism is “Water”.

Detailed explanation-2: -The survival of terrestrial plants depends upon the capacity of roots to obtain water and nutrients from the soil. Directed growth of roots in relation to a gradient in moisture is called hydrotropism and begins in the root cap with the sensing of the moisture gradient.

Detailed explanation-3: -Some common plant stimuli include light, gravity, water, movement of the sun, and touch.

Detailed explanation-4: -Phototropism is the movement of plant parts in response to light. Thus, the stimulus for phototropism is “Light”.

Detailed explanation-5: -The growth movement of plants in response to the stimulus of touch is called thigmotropism. Thus, the stimulus for thigmotropism is “Touch”.