This exam focus covers Exam Focus within Reflex Arc for GCSE Biology. Topic 3: Reflex Arc It is section 12 of 14 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 12 of 14
Practice
15 questions
Recall
20 flashcards
Exam Focus
Exam FavouriteThe reflex arc is tested in 3 out of 5 recent AQA Paper 2 exams, often earning 4–6 marks. Extended "explain" questions on why reflexes are faster, and the role of synapses, are particularly common.
How it is tested:
- Describe the sequence: List all five components — receptor, sensory neurone, relay neurone, motor neurone, effector — in the correct order.
- Explain why reflexes are fast: Shorter pathway (spinal cord vs brain); no conscious decision required.
- 6-mark extended response: "Describe and explain a reflex arc" — include the pathway, synapse transmission, directionality, and the adaptive value of the reflex.
- Synapse mechanism: Neurotransmitter release → diffusion → binding → new impulse. Must state that synapse ensures one-directional transmission.
- Required Practical (RPA7): Measuring reaction time using the ruler-drop method. Questions ask about control variables, calculating mean, and why results vary between trials.