Question

Match the following:

• A. A-III, B-IV, C-II, D-I
• B. A-III, B-IV, C-I, D-II
• C. A-II, B-I, C-IV, D-III
• D. A-IV, B-III, C-I, D-II

Hint:

Bowman's capsule $\rightarrow$ Ultrafiltration Ascending limb $\rightarrow$ Impermeable to water PCT $\rightarrow$ Obligatory reabsorption DCT $\rightarrow$ Facultative reabsorption

Answer 1

The Correct Option is B

Concept: Different parts of nephron perform specialized functions in urine formation. Urine formation involves: \[ \text{Ultrafiltration} \rightarrow \text{Reabsorption} \rightarrow \text{Secretion} \] Knowledge of nephron physiology is essential for solving matching questions.

Step 1: Identify the function of Bowman's capsule. Bowman's capsule surrounds the glomerulus. Blood pressure inside glomerular capillaries forces plasma into Bowman's capsule. This process is called: \[ \boxed{\text{Ultrafiltration}} \] Therefore, \[ A \rightarrow III \]

Step 2: Identify the function of ascending limb of Loop of Henle. Ascending limb actively transports salts. However, it does not allow water movement. Hence it is: \[ \boxed{\text{Impermeable to water}} \] Therefore, \[ B \rightarrow IV \]

Step 3: Identify the function of PCT. Nearly 65--70% water is reabsorbed in PCT. This occurs automatically and continuously. Hence it is: \[ \boxed{\text{Obligatory water reabsorption}} \] Therefore, \[ C \rightarrow I \]

Step 4: Identify the function of DCT. Water reabsorption in DCT depends upon ADH. Therefore it is: \[ \boxed{\text{Facultative water reabsorption}} \] Hence, \[ D \rightarrow II \]

Step 5: Construct the final matching. \[ A-III,\quad B-IV,\quad C-I,\quad D-II \] \[ \boxed{\text{Option (B)}} \]