This deep dive covers Tropisms — Plant Responses to Stimuli within Plant Hormones for GCSE Biology. Topic 11: Plant Hormones It is section 1 of 12 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
🌱 Tropisms — Plant Responses to Stimuli
Plants respond to stimuli but more slowly than animals:
| Tropism | Response to | Example |
|---|---|---|
| Phototropism | Light | Shoots grow towards light (positive) |
| Geotropism/Gravitropism | Gravity | Roots grow down (positive); shoots grow up (negative) |
Practice questions for Plant Hormones
When a plant shoot is lit from one side, where does auxin accumulate?
Explain how auxin causes gravitropism (geotropism) in plant roots.
Quick recall flashcards
What is phototropism?
Phototropism is the growth response of a plant to light. Shoots show positive phototropism — they grow towards the light source.
What is gravitropism?
Gravitropism is the growth response of a plant to gravity. Roots show positive gravitropism (grow downward, towards gravity). Shoots show negative gravitropism (grow upward, away from gravity).