Plants grow towards the sun to be able to generate enegy by photosynthesis
What causes the plant to grow towards the light?
I have always wondered that!
The driving force behind this movement is the hormone auxin
The growth of plants toward light is particularly important at the beginning of their life cycle.
Phototropins are sensitive to blue light. When they sense it, they give signals that makes hormone auxin. This causes cells on the shaded side of the stem to elongate, bending the plant towards the light.