The table shows urine collected over two equal periods from the same healthy person.
Table
| Period | Urine volume in cm3\mathrm{cm^3}cm3 | Urea concentration in g dm−3\mathrm{g\,dm^{-3}}gdm−3 |
|---|---|---|
| P | 600 | 20 |
| Q | 300 | 40 |
Use mass=concentration×volume\mathrm{mass}=\mathrm{concentration}\times\mathrm{volume}mass=concentration×volume, with volume in dm3\mathrm{dm^3}dm3.
Which comparison is correct?
the same urea mass is excreted; Q is consistent with less water reabsorption
twice the urea mass is excreted in Q; Q is consistent with more water reabsorption
the same urea mass is excreted; Q is consistent with more water reabsorption
half the urea mass is excreted in Q; Q is consistent with less water reabsorption
94 exam-style questions on Edexcel GCSE Biology 7.4 Blood glucose and the urinary system, covering 7.4.1 Insulin and blood glucose control, 7.4.2 Glucagon and blood glucose regulation, 7.4.3 Type 1 and type 2 diabetes, 7.4.4 Structure of the urinary system, 7.4.5 Structure and function of the nephron, 7.4.6 ADH and water regulation, 7.4.7 Treatments for kidney failure, and 7.4.8 Production of urea in the liver. Each one has a worked solution and a mark scheme showing where the marks go.