The main function of Henle's loop is

Mammals have the ability to produce

Which adaptation is shown by desert organisms?

Which of the following statements about the reabsorption process in Henle's loop are correct?
$(a)$ The descending limb of Henle's loop is permeable to water but almost impermeable to electrolytes.
$(b)$ Urine gets concentrated in Henle's loop.
$(c)$ Reabsorption of $Na^+$ and water takes place in Henle's loop.
$(d)$ Active or passive transport of electrolytes occurs in the ascending limb of Henle's loop.
Choose the correct answer from the options given below:

Describe the counter-current mechanism.

If Henle's loop were absent from mammalian nephron,which of the following is to be expected?