Draw a labelled diagram of a neuron. Explain how a nerve impulse passes from one neuron to the next.

1. 1 · Define in one line. A neuron is a nerve cell, the structural and functional unit of the nervous system.
2. 2 · Trace the impulse. Stimulus at the dendrite → electrical impulse → cell body → axon → axon endings.
3. 3 · Explain the synapse. The endings release neurotransmitters into the synaptic cleft; these cross the gap and start an impulse in the next neuron.
4. 4 · Draw the neuron. [Diagram: dendrites, cell body, nucleus, axon, myelin sheath, nodes of Ranvier, axon endings, arrow for the impulse]
5. 5 · Link to daily life. Such a chain of neurons carries the smell of food to your brain in a fraction of a second.
6. 6 · Close in one line. So electrical impulses inside neurons, and chemicals between them, carry every message.

Scoring tip: Draw the arrow for the direction of the impulse; it is a mark many students lose.