Discover how plants bend and grow toward light sources. This response helps plants maximize their exposure to sunlight for photosynthesis. Watch as auxin hormones accumulate on the shaded side, causing differential growth!
🌙 Photoperiodism
Learn how plants track day length to determine when to flower. Short-day plants bloom when nights are long, long-day plants flower when days are extended, while day-neutral plants ignore photoperiod altogether.
🧪 The Science
Both responses involve sophisticated light-sensing mechanisms. Photoreceptors like phytochrome detect light quality and duration, triggering hormonal changes that control growth and development.
🎮 Interactive Learning
Drag the sun to see phototropism in action! Adjust day length to trigger flowering in different plant types. This hands-on approach makes complex plant biology concepts easy to understand.
🌞 Drag the sun to see the plant grow toward the light!
Key:
Light photons
Auxin hormone
Leaves
Shaded side
Why do plants lean towards the sun?
Ever notice how a houseplant on a windowsill seems to reach for the light? That's phototropism in action! It's a plant's natural tendency to grow toward its light source. This simulation shows you how it works:
The plant's tip senses where the sunlight is coming from.
A plant hormone called auxin moves to the shady side of the stem.
This hormone buildup causes the shady side to grow faster, making the whole stem bend toward the sun!
As it bends, it also sprouts new leaves to soak up as much light as possible.
Drag the sun around and watch the plant chase the light!
Short-Day Plant (e.g., Chrysanthemum)
Long-Day Plant (e.g., Spinach)
Day-Neutral Plant (e.g., Tomato)
How do plants know when to flower?
It's all about timing! Plants can sense the changing seasons by measuring the length of the day and night. This response, called photoperiodism, tells them when it's the right time to bloom.
Short-day plants are late bloomers, waiting for the long nights of late summer or fall.
Long-day plants prefer the short nights of summer to show off their flowers.
Day-neutral plants are easygoing—they'll flower whenever they're ready, no matter how long the day is.