Final answer:
The upper component of the dialyzer has a higher solute concentration than the lower compartment to successfully remove wastes from the blood during dialysis.
Step-by-step explanation:
The concentration of solutes likely differs between the upper component of the dialyzer and the lower compartment, containing the fresh dialysate, by having a higher solute concentration in the upper component.
This allows the process of diffusion to occur, where waste molecules like urea move from an area of higher concentration (the blood) to an area of lower concentration (the dialysate) down their concentration gradient. This helps to remove wastes from the blood during dialysis.