Plants exhibit phototropism, or growing toward a light source, and many light sources such as the sun and most artificial lights produce unpolarized light. Given these facts, what is called when plants grow toward the sun or an artificial light among the following options:
- Exfoliation
 - Brownian motion
 - heat energy
 - phototropism
 - photovoltaic
 - autumn
 - peachleaf willow
 - mitosis


 

    phototropism     