Refer to the following graph of an action potential to answer the question.

The membrane's permeability to sodium ions is greatest at label ________.
A) A
B) B
C) C
D) D

Question

Refer to the following graph of an action potential to answer the question.

The membrane's permeability to sodium ions is greatest at label ________.
A) A 
B) B 
C) C 
D) D

Quizplus · Accepted Answer

At label B, the membrane's permeability to sodium ions is greatest as there is a rapid influx of sodium ions into the cell, resulting in the depolarization phase of the action potential. This is due to the opening of voltage-gated sodium channels, allowing more sodium ions to flow into the cell than any other point in the graph.

Refer to the Following Graph of an Action Potential to Answer