Explain how active transport and membrane permeability contribute to establishing and maintaining a resting potential of approximately −70 mV-70\text{ mV}−70 mV across the axon membrane of a neurone.
A researcher exposed an isolated giant axon of a squid to cyanide, a metabolic poison that inhibits the electron transport chain in mitochondria. Following the addition of cyanide, the resting potential of the axon was observed to slowly depolarise from −70 mV-70\text{ mV}−70 mV to 0 mV0\text{ mV}0 mV. Explain why.
10 exam-style questions on AQA A Level Biology Nervous coordination (A-level only), covering Nerve impulses (A-level only) and Synaptic transmission (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.