WJEC A Level Biology
WJEC A Level Biology 3.8 The Nervous System Exam Questions
Free WJEC A Level Biology exam questions on 3.8 The Nervous System, with mark schemes. Covers neurones, reflexes, resting and action potentials, synapses and the effects of drugs.
3.8 The Nervous System exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
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WJEC A Level Biology Flashcards (Anki & Quizlet)
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Use them on Anki or Quizlet, then test yourself with the questions on this page.
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About WJEC A Level Biology 3.8 The Nervous System
This topic covers how nervous impulses are generated and transmitted.
What you need to know
- Neurones and reflexes Sensory, relay and motor neurones and the reflex arc.
- Action potentials Resting potential about -70 mV, depolarisation by sodium influx, repolarisation by potassium efflux, refractory period.
- Conduction Myelination and saltatory conduction increase speed.
- Synapses Acetylcholine release, binding and breakdown by acetylcholinesterase, and the effects of drugs and organophosphates.
Common mistakes in 3.8 The Nervous System
- Saying the impulse travels by electrons along the axon.
- Forgetting the role of calcium ions at the synapse.
- Confusing depolarisation and repolarisation.
Try three 3.8 The Nervous System exam-style questions
1. Explain why impulses travel in one direction only. (2 marks)
Show the mark scheme answer
The refractory period stops the previous section being stimulated again (1), and neurotransmitter is only released from the presynaptic neurone (1).
2. Describe the role of calcium ions at a synapse. (2 marks)
Show the mark scheme answer
Calcium ions enter the presynaptic knob (1), causing vesicles to fuse and release neurotransmitter (1).
3. Explain how organophosphates affect synapses. (2 marks)
Show the mark scheme answer
They inhibit acetylcholinesterase (1), so acetylcholine is not broken down and the postsynaptic neurone keeps firing (1).
3.8 The Nervous System FAQs
What does The Nervous System cover?
Neurones, reflexes, action potentials, conduction and synapses.
Do I need to know nerve nets?
Yes, the simple nervous systems of cnidarians compared with mammals.
What is saltatory conduction?
Impulses jumping between nodes of Ranvier in myelinated neurones.
Revise this topic with flashcards: WJEC A Level Biology Flashcards, with mark scheme answers for Anki and Quizlet.
