Plants cannot walk or run, but they can still respond to things around them. A change that makes a plant act is called a stimulus. Plants respond slowly, often by growing in a certain direction.
What plants respond to
- Light — shoots grow towards light so the leaves can catch more sunlight.
- Water — roots grow towards water in the soil.
- Gravity — roots grow downwards, and shoots grow upwards.
- Touch — some plants react when touched, like the shy Mimosa (semalu) that folds its leaves.
Key idea
Shoots grow towards light and upwards. Roots grow towards water and downwards. This helps the plant make food and survive.
Example
A sunflower on a windowsill leans and grows towards the sunlight coming through the glass, so its leaves can catch more light.
Remember
- Plant responses are slow, not fast like ours.
- Growing towards light and water helps a plant make food and stay alive.
- The Mimosa plant folds its leaves when it is touched.