Question

An inhibitory stimulus has occurred. B. Chemically gated potassium channels have opened. C. Excessive potassium has diffused out causing hyperpolarization. D. Excessive depolarization of the axon has occurred.

Answer 1

Given question is incomplete. Complete question has been attached.

Answer:

C. Excessive potassium has diffused out causing hyperpolarization.

Explanation:

The nerve action potential can be divided into following stages:

• Stimulus is detected by the cell in resting stage.
• Sodium channels in the membrane open from where influx of sodium ions occur which is called depolarization
• After a while, sodium channels close and potassium channels open from where efflux of potassium ions occur which is called repolarization.
• The membrane potential further lowers due to continous efflux of potassium ions which is called hyperpolarization.
• After a while potassium channels close and membrane returns to its resting stage.

In the given figure, stage 4 depicts hyperpolarization because the membrane potential has dropped to the lowest point below -70mV. Hence, option C is correct.