MCQ – 74821

The cell membrane of a cell is freely permeable to three ions X, Y, and Z. At resting membrane potential, the respective equilibrium potentials of X and Y are -30mV and -40 mV. What will happen to the membrane potential if a drug is infused which can block the permeability of Z?

Correct Answer � A Explanation

Ans. A. Depolarisation

• In this question if Z has a reversal potential or original RMP was more negative (e.g., -70 or -90 mV) then closure of C ion channels would shift the RMP closer to reversal potential of A, B thus depolarising the cell.