Take this Quiz: A-Level Biology: Nervous Coordination and Muscles | Zestly

Question 1

Which specific mechanisms are primarily responsible for maintaining the resting potential of a neuron at approximately -70 mV?

Accepted Answer

Active transport of $3	ext{Na}^+$ out and $2	ext{K}^+$ into the cell via the sodium-potassium pump

Question 2

During an action potential, what is the primary cause of the repolarisation phase?

Accepted Answer

The opening of voltage-gated potassium channels and closure of sodium channels

Question 3

Which of the following statements accurately describe the all-or-nothing principle in neuronal signalling?

Accepted Answer

An action potential is only triggered if the stimulus reaches the threshold value

Question 4

How does myelination increase the speed of nerve impulse conduction?

Answer

By increasing the diameter of the axon to reduce electrical resistance

Answer

By forcing the action potential to jump between nodes of Ranvier

Answer

By increasing the density of voltage-gated sodium channels along the entire axon

Answer

By insulating the axon to prevent the leakage of potassium ions

Question 5

Which factors contribute to an increase in the speed of an action potential along an axon?

Answer

Increased axon diameter

Answer

Decreased temperature

Answer

Presence of a myelin sheath

Answer

Increased body temperature within physiological limits