HARD
AS and A Level
IMPORTANT
Earn 100
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.
Important Questions on Control and Coordination
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?
MEDIUM
AS and A Level
IMPORTANT
Look in the given figure and explain what is meant by the all-or-none law.
MEDIUM
AS and A Level
IMPORTANT
Describe the relationship between the strength of the stimulus and the size of the receptor potential that is generated.
MEDIUM
AS and A Level
IMPORTANT
Describe the relationship between the strength of the stimulus applied and the frequency of action potentials generated in the sensory neurone.
HARD
AS and A Level
IMPORTANT
What determines the maximum frequency of action potentials in a neurone?
HARD
AS and A Level
IMPORTANT
Threshold potentials in receptor cells can increase and decrease. Suggest the likely advantages of this.
