AP BIOLOGY

Detailed explanation-1: -The response of an organism, usually a plant, to an environmental stimulus is called a tropism. Some common plant stimuli include light, gravity, water, movement of the sun, and touch. The naming of the tropism is associated with the stimulus.

Detailed explanation-2: -Plants respond to changes in the environment by growing their stems, roots, or leaves toward or away from the stimulus. This response, or behavior, is called a tropism.

Detailed explanation-3: -Positive tropism is when a plant moves towards a stimulus. Negative tropism is when a plant moves away from a stimulus.

Detailed explanation-4: -Because plants require sunshine to thrive, they will tilt or migrate towards the source of light. Phototropism is the name given to this type of movement. Negative phototropism occurs when a plant travels away from a light source. Positive phototropism occurs when plants grow toward the source of light.