Photoreceptors Practice Test

The idea being tested is that cones have three different photopigments, each tuned to a different part of the spectrum, which together provide color vision. In humans, cones carry cyanolabe (blue-sensitive pigment), chlorolabe (green-sensitive), and erythrolabe (red-sensitive). This trio lets the visual system compare the signals from the blue, green, and red channels to distinguish colors. Rods, on the other hand, use a different pigment called rhodopsin and are responsible for vision in low light, not color vision. So the statement that cones contain cyanolabe, chlorolabe, and erythrolabe best describes cone photopigment distribution.