Question

Assertion :The renal fluid becomes increasing concentrated when it flows down in the descending limb of loop of Henle towards inner medulla, but its concentration decreases in the ascending limb when it flows towards the cortex. Reason: The descending limb of the loop of Henle water is reabsorbed, the ascending limb is impermeable to water but salt are absorbed.

• A. Both (A) and (R) are true (R) is the correct explanation to (A)
• B. Both (A) and (R) are true (R) is not the correct explanation to (A)
• C. (A) is true, but (R) is false
• D. (A) is false, but (R) is true

Answer 1

The correct option is A Both (A) and (R) are true (R) is the correct explanation to (A)

• The renal fluid becomes increasingly concentrated because there is the reabsorption of water and other solutes that are important to the body. This happens in the descending limb.
• The ascending limb is impermeable to water. There is an absorption of sodium and potassium ions.
• This results in decreasing the concentration of the filtrate in the ascending limb which moves towards the cortex.
  

Thus, the correct answer is option A.