Which of the following will increase the speed of an action potential moving down an axon?
I.Action potentials move faster in wider axons.
II.Action potentials move faster in axons lacking potassium ion channels.
III.Action potentials move faster in myelinated axons.
A) only I and II
B) only II and III
C) only I and III
D) I, II, and III

Question

Quizplus · Accepted Answer

I is true, as wider axons have less resistance to ion flow, allowing the action potential to travel faster. 
II is false, as potassium channels are necessary for repolarization of the axon and restoration of resting potential, which allows for the action potential to continue down the axon. 
III is true, as myelin insulates the axon and allows for saltatory conduction, where the action potential jumps from node to node, increasing the speed of transmission.

Which of the Following Will Increase the Speed of an Action