Final answer:
In the human retina, the types of photoreceptor cells are rods and cones. Rods are adapted for low-light vision and do not perceive color, while cones are responsible for color vision and function well in bright light. Amacrine cells, bipolar cells, and horizontal cells are involved in signal processing but are not photoreceptors.
Step-by-step explanation:
The types of photoreceptor cells in the human retina are rods and cones. These photoreceptors are responsible for converting light into signals that can be interpreted by the brain to form visual images. Rods are highly sensitive to light and are responsible for vision in low-light conditions but do not mediate color vision. Cones, on the other hand, respond to different wavelengths of light, allowing for color vision and greater visual acuity, predominantly in bright light.
Other cells mentioned, such as amacrine cells, bipolar cells, and horizontal cells, while important for the processing of visual information in the retina, are not photoreceptors. Bipolar cells receive signals from photoreceptors and transmit them to ganglion cells, which relay information to the brain. Horizontal cells aid in creating visual contrasts, and amacrine cells play a role in image processing and the refinement of visual signals, but neither are involved in direct light sensing.