Question

In a polarized state, the resting potential (average) of axon is -------------millivolts.

• A. \(-30\)
• B. \(-70\)
• C. \(+30\)
• D. \(+60\)

Hint:

The inside of a resting axon is negative with respect to the outside.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
At rest, the axon membrane is much more permeable to \(\text{K}^{+}\) than to \(\text{Na}^{+}\). The \(\text{Na}^{+}\)-\(\text{K}^{+}\) pump sends out 3 \(\text{Na}^{+}\) for every 2 \(\text{K}^{+}\) taken in.

Step 2: Charge on the two sides
This makes the inside of the membrane negative and the outside positive. This polarised state is the resting potential.

Step 3: Value
The average resting potential of an axon is about \(-70\) mV.

Final Answer:
The resting potential is about -70 mV. \[ \boxed{\text{(B) }-70} \]