The counter-current multiplier system changes the isotonic glomerular filtrate into

What is a characteristic feature of the metanephric kidney?

The function of the loop of Henle is:

What does the following figure represent?

The Loop of Henle is primarily responsible for the reabsorption of which of the following?

The increase in osmolarity from outer to inner medullary interstitium is maintained due to:
$(i)$ Close proximity between Henle's loop and vasa recta
$(ii)$ Counter current mechanism
$(iii)$ Selective secretion of $HCO_{3}^{-}$ and hydrogen ions in $PCT$
$(iv)$ Higher blood pressure in glomerular capillaries