Question

When compared with the cones of the retina, the rods

• A. are more sensitive to low-intensity light
• B. adapt to darkness before the cones
• C. are most highly concentrated on the fovea
• D. are primarily involved in color vision

Answer 1

The correct option is A are more sensitive to low-intensity light

Rods are more sensitive to light and so take longer to fully adapt to the change in light. Rods, whose photopigments regenerate more slowly, do not reach their maximum sensitivity for about two hours. Cones take approximately 9–10 minutes to adapt to the dark. So rods adapt to darkness after the cones. Rods are not present in the fovea. The cones are primarily involved in color vision.