Mitchell has to write a paper about the excretory system for school. Choose the correct way to complete each sentence in Mitchell’s paper. Urine Production Every day, the kidneys filter about gallons of blood to produce about 1 to 2 quarts of urine. Urine is 95 percent water and 5 percent wastes. Urine is formed as a result of filtration and in the tiny tubes within the kidneys’ nephrons. Each minute, about 2.5 cups of blood enters the kidneys through the renal arteries. The blood passes through the nephrons to be filtered. In the of the nephron, unwanted particles of metabolic waste are removed and wanted particles (glucose, vitamins, amino acids, and chloride salts) are reabsorbed into the bloodstream.