During the daylight plants grow through photosynthesis producing sugar (carbohydrates) in their leaves.
At night plants transport the sugars from the leaves to other parts of the plant in need of energy for growth.
Plants get their energy through Cellular Respiration. The plant breaks down sugars made during the day. At night the plant uses these sugar to create Adenosine Triphosphate ATP which is the cell’s energy. While performing this process the plants release carbon dioxide.
The night allows plants to grow and repair. Many plants have rapid growth at night compared to the daylight hours. Plants repair cellular damage, build tissue, extend their roots and grow their leaves.