1. Phototropism: The Real Mechanism
Plants exhibit phototropism, which is the growth response to light. This means they bend towards a light source, not necessarily grow directly towards it. The bending is caused by an uneven distribution of the plant hormone auxin.
2. Auxin's Role:
Auxin accumulates on the shaded side of a plant stem, promoting cell elongation. This causes the stem to bend towards the light. If the light is directly above the plant, it might grow straight up, but the growth is still influenced by the light source.
3. Not Just "Towards" the Light:
While plants bend towards the light, the direction of growth can also be influenced by other factors:
* Gravity: Plants also exhibit gravitropism, growing roots downwards and stems upwards.
* Other Environmental Cues: Light quality, intensity, and duration all play a role in growth direction.
In Summary:
While it's true that plants grow towards light in a general sense, it's more accurate to say that they exhibit phototropism, bending towards the light source due to the uneven distribution of auxin. This process involves a complex interplay of hormonal and environmental factors.
