Final answer:
The sensory receptor cells that are active in dim light are the rods, which are specialized for low-light vision and do not provide color information.
Step-by-step explanation:
The sensory receptor cells active in dim light are the rods. The rods are highly sensitive photoreceptors in the retina that allow for vision in low-light conditions. Unlike cones, which are responsible for color vision and function well under bright light conditions, rods are more numerous and equipped with a pigment called rhodopsin that is sensitive to dim light, aiding in night vision and peripheral vision.
The fact that rods do not provide color information is why humans typically do not perceive colors in very low-light scenarios, seeing mostly in shades of gray. The sensory receptor cells active in dim light are called rods. These cells are responsible for peripheral vision, vision in dark environments, and motion detection. They are more sensitive than cones and do not yield color information.