Final answer:
The false statement is that "Cones have disks," as cones have folds of membrane rather than the membrane-bound discs found in rods. Rods detect gray shades and operate in low light, mainly in the retina's periphery, while cones handle color vision and are concentrated in the fovea.
Step-by-step explanation:
The statement that is FALSE when distinguishing rods and cones is that "Cones have disks." In fact, cones do not have stacks of membrane-bound discs like rods but instead have folds of membrane. While rods and cones are both photoreceptors, they have notable differences in their structure and function, discussed below:
- Rods are designed to function in low light and can only detect shades of gray. They are more numerous than cones and are mostly found in the peripheral regions of the retina.
- Cones are responsible for color vision and function well in bright light. There are three types of cones—L, M, and S—each sensitive to different wavelengths (colors). Cones are concentrated in the fovea, the central region of the retina.
Both rods and cones have inner segments containing the nucleus and other organelles, but their outer segments differ distinctly. Rod outer segments are long and columnar with stacks of membrane-bound discs containing the rhodopsin pigment. In contrast, cone outer segments are shorter, tapered and have folds of membrane rather than stacked discs.
Additionally, rods and cones have different patterns of synaptic connections and are distributed differently across the retina, with cones densely packed in the fovea and rods dispersed more widely in the periphery.