Question

Permeability of the axolemma to potassium ions is higher than its permeability to sodium because

• A. potassium ions move faster than sodium ions
• B. potassium ions are smaller than sodium ions
• C. potassium leakage channels are leakier than sodium leakage channels
• D. sodium leakage channels are leakier than potassium leakage channels

Answer 1

The correct option is C potassium leakage channels are leakier than sodium leakage channels

Permeability of the axolemma to potassium ions is higher than its permeability to sodium because potassium leakage channels are leakier than sodium leakage channels.
Speed of movement of both the ions are dependent on various other factors such as size, charge to mass ratio etc. The movement itself is dependent on the opening or closing of the gates of the ion channels. It cannot be determined solely by any one factor.
Potassium ions are in fact greater in radius than sodium ions.