Final answer:
The statement is false; the composition of the filtrate can change in the renal tubules and collecting ducts through the processes of tubular reabsorption and secretion before becoming urine.
Step-by-step explanation:
The statement that after the filtrate reaches the renal pelvis, its composition will not significantly change and it will be excreted as urine is false. In the kidney, there are several steps in the formation of urine: glomerular filtration, tubular reabsorption, and tubular secretion. These processes occur in the nephron, the functional unit of the kidney. Tubular reabsorption happens predominantly in the renal tubule, where water and necessary solutes are reabsorbed back into the bloodstream.
Consequently, the filtrate that will become urine is concentrated as it progresses through the tubules, and its composition can change up until it reaches the collecting ducts. The collecting ducts play a crucial role in the regulation of water and solute balance. Furthermore, substances such as electrolytes and wastes like urea can be added or removed during its passage through the renal tubules and collecting ducts, refining the urine before it drains into the renal calyces and the renal pelvis.