NEET BIOLOGY

Detailed explanation-1: -Growth toward or away from a stimulus is known as a tropism. You might have noticed that plants bend toward the light. This is an example of a tropism where light is the stimulus, known as phototropism (Figure below). To obtain more light for photosynthesis, leaves and stems grow toward the light.

Detailed explanation-2: -Responsive growth movements toward or away from an external stimulus are called tropisms. If the plant movement is toward the stimulus, it is a positive tropism; away from the stimulus, a negative tropism. The tropic response to unidirectional light is called phototropism.

Detailed explanation-3: -Tropism is when a plant moves in response to an external stimulus in the environment. Positive tropism is when a plant moves towards a stimulus. Negative tropism is when a plant moves away from a stimulus.

Detailed explanation-4: -Gravitropism ensures that roots grow into the soil and that shoots grow toward sunlight. Growth of the shoot apical tip upward is called negative gravitropism, whereas growth of the roots downward is called positive gravitropism.

Detailed explanation-5: -The movement or growth of any part of a plant in response to an external stimulus is called tropism or tropic movement.