1. Neurons and synapses

2. U 1 Neurons transmit electrical impulses
U 1 Neurons transmit electrical impulses. U 2 The myelination of nerve fibres allows for salutatory conduction.

3. U 3 Neurons pump sodium and potassium ions across their membranes to generate a resting potential.
Sodium- potassium pump maintains high Na+ outside and high K+ inside to maintain the resting membrane potential.
Active transport of 3 Na+ out and 2 K+ in. (uses ATP)

4. U 4 An action potential consists of depolarization and repolarization of the neuron. U 9 A nerve impulse is only initiated if the threshold potential is reached.

5. U 5 Nerve impulses are action potentials propagated along the axons of neurons. U 6 Propagation of nerve impulses is the result of local currents that cause each successive part of the axon to reach the threshold potential.

6. U 7 Synapses are junctions between neurons and between neurons and receptors or effector cells.

7. A 1 Secretion and reabsorption of acetylcholine by neurons at synapses

8. S 1 Analysis of oscilloscope traces showing resting potentials and action potentials.

9. A 2 Blocking of synaptic transmission at cholinergic synapses in insects by binding of neonicotinoid pesticides
Neonicotinoid
use was linked in a range of studies to adverse ecological effects, including honey-bee colony collapse disorder(CCD) and loss of birds due to a reduction in insect populations.