Question

Which of these does not take place when a stimulus is applied to a polarized axonal membrane?

(a) It becomes permeable to sodium ions

(b) The membrane is depolarized

(c) There is a slow influx of sodium ions

(d) Outer surface of the membrane becomes negatively charged

This question was addressed to me by my school teacher while I was bunking the class.

Question is taken from Neuron-2 in division Neural Control and Coordination of Biology – Class 11

Answer 1

Correct answer is (c) There is a slow influx of sodium ions

Explanation: When a stimulus is applied to a polarized axonal membrane, the polarity of the membrane is reversed. It becomes permeable to sodium ions and leads to its rapid influx. Outer surface of the membrane becomes negatively charged.