Which term refers to the response of a plant in growing towards light?

Phototropism is the term that describes the growth response of a plant toward light. This phenomenon occurs because plants possess specialized cells that produce auxins, which are plant hormones. When light is detected, usually through photoreceptors, auxins redistribute towards the shaded side of the plant. This uneven distribution of auxins causes the cells on that side to elongate more than those on the light-exposed side, resulting in the plant bending toward the light source. This response maximizes light absorption for photosynthesis, which is crucial for a plant's growth and survival.

Geotropism refers to a plant's growth response to gravity, while hydrotropism describes growth in response to moisture gradients. Tropism is an umbrella term that encompasses various directional growth responses in plants, such as phototropism and geotropism, but it does not specify the stimulus. Therefore, phototropism is the most accurate term for the specific response of a plant growing towards light.