Question Detail

ZOO 101 ZOO 101 Past Questions Objective Question

Question

Which ion is primarily responsible for depolarization during an action potential?
Options
A Potassium (K+)
B Sodium (Na+)
Correct Answer
C Calcium (Ca2+)
D Chloride (Cl-)
Correct Answer

Option B is the correct answer.

Detailed Explanation

Depolarization occurs when voltage-gated sodium channels open, allowing Na+ to rapidly enter the cell and make the interior less negative.

Hint

This ion is more concentrated outside the neuron at rest.

Question Info