Question

A nerve fiber during resting stage is
A) more permeable to Na+
B) more permeable to K+
C) equally permeable for Na+ and K+
D) less permeable to K+

Answer 1

Hint: Action potential is the nerve impulse which travels along the axon of nerve, which occurs due to difference in the electric potential across the membrane, and this potential is due to presence of ion gated channels such as Na+ and k+ channels.

Complete answer:
Humans have different types of cells, which are excitable to various external stimuli, which cause the action potential, similarly nerves cause action potential, and this membrane potential is due presence of voltage gated channels which cause the exchange of ions.
In some cells, such as nerves, even if there is no stimulus on the cells still it causes unequal distribution of ions on both sides of the cell membrane of the nerve cells.
During Resting membrane potential, there is a difference in membrane potential of the different ions such as sodium, potassium, chloride, etc. Which in turn activates the membrane voltage ions channels, ion exchanger, etc.
The general resting membrane potential of a cell occurs due to separation of potassium ions from the intracellular of the cell, and relatively immobile anions that are present across the membrane of the cell.
As the permeability of membrane for potassium is much higher than that for other ions, and at the same time potassium is a strong chemical gradient for other ions, because of this potassium ions flow from the intracellular into the extracellular space which forms the positive charge.
During the resting membrane potential, potassium permeability is higher and close to that of potassium reversal potential.

So, the correct option is B.

Note: If the axons of the nerve do not conduct any action potential across the membrane is called resting membrane potential, during this the membranes of the cells are more permeable to potassium ions and less permeable or impermeable to sodium ions.