This key facts covers Commercial Uses of Plant Hormones within Plant Hormones for GCSE Biology. Topic 11: Plant Hormones It is section 3 of 12 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
📌 Commercial Uses of Plant Hormones
- Auxins: Weed killers (make weeds grow too fast), rooting powder
- Ethene: Ripens fruit (bananas picked green, ripened with ethene)
- Gibberellins: Promote seed germination, increase fruit size
Visual: Plant Hormones & Tropisms
Remember: Auxin in SHOOTS: more = more growth | Auxin in ROOTS: more = less growth | This explains tropisms!
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).