Rhodopsin is the pigment found in which cells?

• A. Cone cells
• B. Hair cells
• C. Rod cells
• D. Olfactory cells

Answer: (C)

Rhodopsin is the photopigment in the rod cells of the retina, which are specialized for detecting light in dim conditions. Rods enable night vision and grayscale perception, and their pigment rhodopsin is a molecule made of an opsin protein bound to retinal. When light activates rhodopsin, retinal changes shape and triggers a signaling cascade that leads to the rod cell sending a signal to the brain. In contrast, cone cells use different pigments (photopsins) for color vision in bright light, hair cells function in hearing and balance, and olfactory cells detect smells. So rhodopsin is found in rod cells.