What do you need to compare between different types of cones in order to differentiate wavelengths?

• A. Absorption rate
• B. Bleaching rate
• C. Receptor adaptation
• D. Concentration of photopigment

Answer: (A)

Understanding color involves how each type of cone’s photopigment responds to different wavelengths. Each cone contains a pigment with a distinct absorption spectrum, so it absorbs photons differently across the light spectrum. By comparing how much each cone type absorbs at a particular wavelength, the visual system can tell which wavelength is present and thus distinguish colors. Bleaching rate relates to how pigment recovers after light exposure, not to identifying wavelength patterns. Receptor adaptation changes sensitivity over time, not the specific wavelength information. The concentration of photopigment affects overall sensitivity, but the key differentiator for wavelengths is how strongly each cone type absorbs light at that wavelength—i.e., the absorption rate.