試題詳解

51. When light strikes the pigment rhodopsin in a rod cell, retinal dissociates from opsin, initiating a signal-transduction pathway that ________.
(A) depolarizes the neighboring bipolar cells and initiates an action potential in a ganglion cell
(B) depolarizes the rod cell, causing it to release the neurotransmitter glutamate, which excites bipolar cells
(C) hyperpolarizes the rod cell, reducing its release of glutamate, which excites some bipolarcells and inhibits others
(D) hyperpolarizes the rod cell, reducing its release of glutamate, which excites amacrine cells but inhibits horizontal cells
(E) converts cGMP to GMP, opening sodium channels and hyperpolarizing the membrane, causing the rhodopsin to become bleached