The nervous system coordinates and regulates body functions. Fig. 3.1 shows two diagrams, each showing parts of the nervous system in a human. [Figure 3.1]

1. (a)Describe the parts of the nervous system shown in each diagram. diagram A diagram B[4]
2. (b)(i)Name the junction shown in Fig. 3.2.[1]
3. (b)(ii)Draw an arrow on Fig. 3.2 to show the direction that an impulse will travel.[1]
4. (b)(iii)The distance between the two neurones shown in Fig. 3.2 is 0.00003 mm. State this distance in units of µm.[1]
5. (c)Nicotine is a chemical found in cigarette smoke. A molecule of nicotine has a similar shape to a molecule of neurotransmitter. Suggest and explain the effect of nicotine at the junctions between neurones.[3]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.