Depolarization refers to which of the following?

• A. Loss of polarization due to ions across the cell membrane
• B. Propagation of electrical impulse without change in charge
• C. Stabilization of resting membrane potential
• D. Increased polarization across the membrane

Answer: (A)

Depolarization is when the membrane potential becomes less negative, meaning the inside of the cell loses some of its excess negative charge as ions cross the membrane. This happens mainly when positively charged ions like sodium rush into the cell, reducing the voltage difference across the membrane toward zero or even making it positive. That’s why “loss of polarization due to ions across the cell membrane” is the best description. The other ideas describe keeping the resting state, increasing polarity (hyperpolarization), or moving an impulse without a change in charge, none of which capture the shift toward a less negative membrane potential.