This exam focus covers Exam Focus within Plant Hormones for GCSE Biology. Topic 11: Plant Hormones It is section 10 of 12 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 10 of 12
Practice
15 questions
Recall
20 flashcards
Exam Focus
Frequently Examined — AQA Paper 2 (High Mark Value)Plant hormones carry the highest mark allocation in Unit 6 when examined — questions of 10-14 marks have appeared in AQA Paper 2 (2020 and 2022). This topic must be prepared thoroughly. Common question formats:
- Explain phototropism using auxin (4-6 marks): Must include: auxin moves to shaded side, cells elongate more on shaded side, shoot bends towards light. For 6 marks, add: auxin produced at tip, lateral transport, reference to cell elongation mechanism.
- Compare shoot and root auxin responses (3-4 marks): Shoots — high auxin = more growth; Roots — high auxin = less growth. Roots are more sensitive. Use this to explain gravitropism.
- Commercial uses of plant hormones (3-4 marks): Auxin: rooting powder (promotes root growth on cuttings), selective weedkillers. Gibberellin: seed germination, fruit size. Ethylene: fruit ripening. One mark per use with mechanism.
- RPA8 (plant growth practical): Experimental design questions on measuring the effect of different light directions on seedling growth — include valid controls, how to measure bending angle, and reliability.
Most common error: Saying "auxin moves towards the light" — it moves AWAY from the light (to the shaded side). This reversal is one of the most common biology exam mistakes at GCSE.