An investigation was carried out to determine the effect of drinking an excessive amount of water on urine flow. A subject drank 1 liter of water in 5 minutes, and then urine output
was measured. The graph shows how the human adult kidneys responded to regulate water
balance in the body. Urine output was measured every 10 minutes for a little over 3 hours.
Normal output for an average adult is approximately 0.5-1 mL/min.
Urine Production in an Adult
with Normal Kidney Function
10
8
6
Urine Output (mL/min)
1 ter of water consumed
180
60 120
Time (min)
Note: The answer to question 49 should be recorded on your separate answer sheet.
49 One half-hour after the liter of water was consumed, the urine produced by the kidneys was
(1) between 2 and 3 ml/min
(3) cight times greater than normal
(2) between 4 and 5 ml/min
(4) below the normal range