How Do Plants Know When to Grow or Rest?

Plants use a special kind of clock inside them to know when to grow or rest, just like we use clocks to know when to wake up. This clock is called the circadian rhythm, and it helps plants know when to open their leaves in the morning and close them at night. It works by sensing light and darkness, when there’s more light, they grow; when it gets dark, they rest.

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Examples

A sunflower opens its face toward the sun when it's bright outside, just like we wake up when it's light.
Grass stops growing at night and starts again in the morning because it knows it’s time to rest.
A tree goes to sleep when the sky gets dark, just like you do when you turn off your lights.

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Categories: Biology · plants,biology,circadian rhythm