Final answer:
The statement is false; in aglomerular kidneys, secretion is more important compared to filtration as waste removal is primarily achieved through tubular secretion due to the absence of glomeruli for filtration.
Step-by-step explanation:
The statement 'In aglomerular kidneys, secretion plays a much smaller role than filtration' is false. In kidneys that lack glomeruli, such as aglomerular kidneys found in some fish species, secretion is actually of greater importance compared to glomerular filtration because these kidneys do not filter blood through glomeruli. Instead, they rely heavily on tubular secretion to remove waste from the blood directly into the tubules.
During the three steps of urine formation, which are glomerular filtration, tubular reabsorption, and tubular secretion, each one plays a crucial role in the kidneys' ability to process and produce urine. In typical mammalian kidneys with glomeruli, about 200 liters of filtrate is produced every day, but most of the fluid is reabsorbed back into the bloodstream leaving less than two liters to be excreted as urine.