Answer:
Phototropism is defined as the movements of plants in response to sunlight. In this case sunlight is the stimuli.
Tropism is defined as the movement of a plant or a part of a plant in response to a certain stimuli.
Negative phototropism is the movement of plant or its part away from sunlight. Such as the growth of roots of a plant deeper inside the ground to absorb nutrients from the soil.
Explanation: