Final answer:
A non-functional retinoblastoma protein causes tumors specifically in the cells of the retina because it fails to regulate the cell cycle, resulting in uncontrolled cell division. This is significant in the retina because the retinoblastoma protein plays a crucial role in normal vision function.
Step-by-step explanation:
A non-functional retinoblastoma protein causes tumors specifically in the cells of the retina because the retinoblastoma protein acts as a tumor suppressor that regulates the cell cycle and prevents uncontrolled cell division. When the retinoblastoma protein is non-functional, it fails to properly regulate the cell cycle, resulting in uncontrolled cell division and the formation of tumors. This is particularly significant in the retina because the retinoblastoma protein plays a crucial role in the normal vision function of the eye.