NEET BIOLOGY

Detailed explanation-1: -Phototropism. Plants grow towards or away from the light, the type of tropism in the response to light is called phototropism. In general, the stems usually show positive phototropism, while roots show negative phototropism. Leaves also positively respond toward the source of light.

Detailed explanation-2: -The correct option is B tropism. The movement of a whole plant or a part of plant, in response to the direction of stimulus is called tropism. The stimulus can be water, sunlight or gravity.

Detailed explanation-3: -Tropisms can have a sign: positive if the plant grows toward or in the direction of the stimulus or negative if it moves away from the stimulus.

Detailed explanation-4: -In a positive tropism, the plant moves towards the stimulus. One familiar example is positive phototropism, in which a plant moves towards sunlight. Time lapse photography allows us to appreciate the tropisms of plants.

Detailed explanation-5: -A tropism is plant movement in response to an external stimulus in the environment. If a plant moves towards a stimulus, then it exhibits positive tropism; if a plant moves away from a stimulus, then it exhibits negative tropism.