Depolarization of the cell membrane occurs when there is a rapid influx (inflow) ofMultiple Choicecalcium ions.amino acids.sodium ions.potassium ions.chloride ions.

Depolarization of a cell membrane occurs becauseMultiple ChoiceSodium ions are blocked from entering the cellMore sodium ions diffuse into the cell than potassium ions diffuse out of itThe concentration of sodium and potassium ions in the extracellular fluid is at equilibriumThe concentration of sodium and potassium ions in the cell is at equilibrium

Depolarization of a cell membrane occurs because

Depolarization occurs becauseMultiple Choicethe extra efflux of potassium ions causes the membrane potential to become slightly more positive than the resting value.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.potassium ions continue to diffuse out of the cell after the inactivation gates of the voltage-gated sodium ion channels begin to close.the increased potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level.

What is produced when depolarization of a cell membrane reaches threshold?Multiple ChoiceA new action potential is produced.An existing action potential is stopped.Voltage-gated ion channels close.The absolute refractory period ends.

A recently depolarized area of a cell membrane cannot generate an action potential because of theMultiple Choiceabsolute refractory period.high concentration of sodium ions in the extracellular fluid.the high concentration of potassium ions in the cytoplasm.presence of receptor sites on the membrane.