Homeostasis & ResponseStudy Notes

Auxin — How It Works

Part of Plant Hormones — GCSE Biology

This study notes covers Auxin — How It Works within Plant Hormones for GCSE Biology. Topic 11: Plant Hormones It is section 2 of 11 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 2 of 11

Practice

15 questions

Recall

20 flashcards

🔬 Auxin — How It Works

Auxin is a plant hormone that controls growth:

Made in shoot tips and root tips
Causes cell elongation (cells grow longer)
Moves away from light in shoots
High concentration in shoots = more growth
High concentration in roots = less growth (roots are more sensitive)

Phototropism explained:

Light hits shoot from one side
Auxin moves to shaded side
Cells on shaded side elongate more
Shoot bends towards light

Keep building this topic

Read this section alongside the surrounding pages in Plant Hormones. That gives you the full topic sequence instead of a single isolated revision point.

Tropisms — Plant Responses to Stimuli Commercial Uses of Plant Hormones How It Works: Auxin and Phototropism Key Definitions

Practice Questions for Plant Hormones

When a plant shoot is lit from one side, where does auxin accumulate?

A. On the side facing the light
B. Equally on both sides
C. On the shaded side, away from the light
D. At the base of the shoot

1 markfoundation

Explain how auxin causes gravitropism (geotropism) in plant roots.

3 marksstandard

Quick Recall Flashcards

How does phototropism work?

Auxin concentrates on the darker side of the plant, causing cells there to elongate more, bending the plant stem toward the light source.

What are plant hormones?

Chemical substances that control various aspects of plant growth, development, and responses to environmental stimuli.

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Tropisms — Plant Responses to Stimuli

Commercial Uses of Plant Hormones