Here's a breakdown:
* Photo: Refers to light.
* Tropism: Refers to growth or movement in response to a stimulus.
Why does it happen?
Plants need light for photosynthesis, the process of converting light energy into chemical energy to fuel their growth. They have a hormone called auxin that helps regulate their growth. When light shines on a plant, auxin accumulates on the shaded side of the stem. This causes the cells on the shaded side to grow longer, resulting in the stem bending towards the light source.
In simple terms: The plant is basically "reaching" for the light it needs to survive and thrive!
