Rods Exposed to Light Will

Question

Rods exposed to light will
A) depolarize due to the opening of sodium channels.
B) hyperpolarize due to the closing of sodium channels.
C) depolarize due to the opening of potassium channels.
D) hyperpolarize due to the closing of potassium channels.
E) fire one action potential for each photon received.

Accepted Answer

When rods are exposed to light, the photopigment molecule called rhodopsin is activated to trigger a signal transduction cascade. This cascade closes Na+ channels, which hyperpolarizes the cell and makes it less likely to fire an action potential. Therefore, the answer is B.