National League for Nursing (NLN PAX) Practice Exam 2025 - Free PAX Exam Practice Questions and Study Guide

Nocturnal mammals have evolved specific adaptations in their eyes to enhance their ability to see in low-light conditions. The correct answer highlights the presence of a greater concentration of rods compared to cones in the retinas of these animals. Rod cells are highly sensitive to light and allow for vision in dim environments, making them essential for nocturnal species that need to navigate and hunt in darkness.

In contrast, cones are responsible for color vision and function best in bright light. Nocturnal animals have fewer cones since they are primarily active at night, where the need for color perception diminishes. This adaptation of having more rods allows nocturnal mammals to maximize their ability to detect light and movement in low-visibility environments. Consequently, the structure of the eye in these mammals is specifically tailored to their lifestyle and habitat, enhancing their survival and efficiency during nighttime activities.