Question

why does depolarization occur?
multiple choice
potassium ions continue to diffuse out of the cell after the inactivation gates of the voltage - gated sodium ion channels begin to close.
the extra efflux of potassium ions causes the membrane potential to become slightly more positive than the resting value.
the increased potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level.
more sodium ions diffuse into the cell than potassium ions diffuse out of it.
the inactivation gates of the voltage - gated sodium ion channels begin to open, and the diffusion of sodium ions decreases.

Explanation:

Depolarization occurs when the membrane potential becomes less negative (more positive). This is due to an influx of positively - charged ions, typically sodium ions. When more sodium ions diffuse into the cell than potassium ions diffuse out, the inside of the cell becomes more positive relative to the outside, leading to depolarization. The other options describe events related to repolarization or hyperpolarization.

Answer:

D. More sodium ions diffuse into the cell than potassium ions diffuse out of it.