HARD
AS and A Level
IMPORTANT
Earn 100
As an action potential begins, the potential difference changes from — 70 mV to + 30m V inside. Annotate a graph to describe what is happening in the axon membrane to cause this depolarisation.
Important Questions on Control and Coordination
HARD
AS and A Level
IMPORTANT
Annotate the given graph to describe what is happening between 1 ms and 2 ms.
HARD
AS and A Level
IMPORTANT
If the action potential starts at time 0, how long does it take for the resting potential to be restored?
MEDIUM
AS and A Level
IMPORTANT
Indicate the refractory period on the given graph.
EASY
AS and A Level
IMPORTANT
What is the role of the refractory period?
HARD
AS and A Level
IMPORTANT
Ouabain is a poison that stops the activity of sodium- potassium pumps. If ouabain is added to part of an axon at a specific place along an axon, action potentials can continue to pass that region for about 1000 impulses. Suggest why they do not stop immediately.
HARD
AS and A Level
IMPORTANT
If myelinated neurones conduct impulses so fast, why do mammals have unmyelinated neurones? What is the likely function of giant axons in earthworms?
EASY
AS and A Level
IMPORTANT
Look in the given figure and explain what is meant by the term receptor potential?
EASY
AS and A Level
IMPORTANT
Look in the given figure and explain what is meant by the term threshold receptor potential?
