Zoology - Excretory Products and their Elimination Question with Solution | TestHub

The countercurrent mechanism changes the isotonic glomerular filtrate into hypertonic urine by increasing salt concentration around the nephron and collecting tubule.

The wall of collecting tubule is permeable to water whereas, ascending limb is impermeable to water.

The absorption of water in DCT is facultative.

As the filtrate passes through the ascending limb, sodium is transported passively in the ascending thick segment.