Question

In the resting state of the neural membrane, diffusion due to concentration gradients, if allowed, would drive 

(a) K⁺ into the cell 

(b) K⁺ and Na⁺ out of the cell 

(c) Na⁺ into the cell 

(d) Na⁺ out of the cell

Answer 1

The correct option is (c) Na⁺ into the cell.

Explanation:

In the resting nerve fibre, the cytoplasm inside the axon has a high concentration of K⁺ and a low  concentration of Na⁺ in contrast to the fluid outside the axon. Thus, if diffusion occurs. then through concentration gradient Na⁺ enters the fibre.