Question

An action potential in the nerve fibre is produced when positive and negative charges on the outside and the inside of the axon membrane are reversed, because

• A. More potassium ions enter the axon as compared to sodium ions leaving it
• B. More sodium ions enter the axon as compared to potassium ions leaving it
• C. All potassium ions leave the axon
• D. All sodium ions enter the axon

Answer 1

The correct option is B More sodium ions enter the axon as compared to potassium ions leaving it

An action potential is a rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern. Sufficient current is required and is produced when positive and negative charges on the outside and the inside of the axon membrane are reversed because more sodium ions enter the axon as compared to the potassium ions are leaving it.

So, option B is the correct option.