Q. Compare the statements A and B.
Statement A : When the urine moves through the descending limb, it becomes hypertonic and as it passes through the ascending limb of Henle's loop, it becomes hypotonic.
Statement B : The descending limb is permeable to sodium ions, while the ascending limb is impermeable to sodium ions.

 2291  219 KCETKCET 2010Excretory Products and their Elimination Report Error

Solution:

When the urine moves through the descending limb, it becomes hypertonic and as it passes through the ascending limb of the loop of Henle, it becomes hypotonic because the descending limb is permeable to water and impermeable to sodium ions, while the ascending limb is impermeable to water and permeable to sodium ions.