BOTANY

Detailed explanation-1: -One important light response in plants is phototropism, which involves growth toward-or away from-a light source. Positive phototropism is growth towards a light source; negative phototropism is growth away from light.

Detailed explanation-2: -A plants response to light has been well documented and studied. It is known to be due to differential elongation of the cells in the plant stem. Stem cells away from the light elongate in response to special auxins (growth hormones) causing the plant stem to bend towards the light.

Detailed explanation-3: -Phototropism describes plant growth in response to a light stimulus. Phototropism is very useful to many plants as they require light for photosynthesis to make their own food.

Detailed explanation-4: -Phototropism, or the differential cell elongation exhibited by a plant organ in response to directional blue light, provides the plant with a means to optimize photosynthetic light capture in the aerial portion and water and nutrient acquisition in the roots.

Detailed explanation-5: -Under normal light conditions auxins are spread out in the plant. But when sunlight varies, auxin is broken down on the sunnier side of the stem. The higher concentration of auxin on the shady side causes the plant cells on that side to grow more so it bends toward the light.