SSC
BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Sodium channels open & sodium ions diffuse out of the neuron.
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Potassium channels open & potassium ions diffuse into the neuron.
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Potassium channels open and potassium ions diffuse into the neuron.
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Sodium channels open and sodium ions diffuse into the neuron.
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Detailed explanation-1: -The diffusion of potassium ions out of a neuron causes regain of resting potential. The resting membrane potential is restored due to action of voltage gated (K+) channels which open due to membrane depolarisation and cause efflux of (K+) ions out of the neuron. It continues till the resting potential becomes-70 mV.
Detailed explanation-2: -What would happen if the potassium channels on a resting neuron were to open? Potassium ions would move out of the cell, and the membrane potential would become more negative.
Detailed explanation-3: -In neurons, the rapid rise in potential, depolarization, is an all-or-nothing event that is initiated by the opening of sodium ion channels within the plasma membrane. The subsequent return to resting potential, repolarization, is mediated by the opening of potassium ion channels.