This exam focus covers Exam Focus within Plant Transport Systems for GCSE Biology. Xylem and phloem structure, water and sugar transport, root hair adaptations, translocation, and practical investigations It is section 13 of 17 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 13 of 17
Practice
19 questions
Recall
24 flashcards
Exam Focus
Frequently ExaminedPlant transport questions appear in almost every AQA Biology Paper 1. These are the most commonly tested areas:
- 6-mark comparison table (Higher tier): "Compare the structure and function of xylem and phloem." Examiners expect: cell status (dead/living), wall reinforcement (lignin/sieve plates), substances transported, direction of flow, energy requirement. Award yourself 1 mark per clear, correct distinction.
- Root hair cell adaptations (2-3 marks): "Explain how root hair cells are adapted for their function." Link each feature to its purpose: long projection → large surface area → faster absorption rate. Never list a feature without explaining why it matters.
- Translocation vs transpiration (2-4 marks): Know the difference. Transpiration = water loss from leaves. Translocation = movement of sugars in phloem. Common exam trap: students confuse which vessel carries which substance.
- "Explain why xylem vessels are dead" (2 marks): State that hollow lumen allows unobstructed water flow, and lignified walls prevent collapse under tension.
- Command word "compare": Always give both sides (xylem AND phloem, or plant AND animal). A one-sided answer cannot score comparison marks.
- Required Practical questions: Expect questions on the potometer method and why the shoot is cut underwater (to prevent air bubbles entering xylem and blocking water flow).
Most common command words: describe, explain, compare, suggest, evaluate.