Question

Assertion :Chloride shift is exchange of $C{l}^{-}$ of plasma and $HC{O}_3^{-}$ of RBC's. Reason: Chloride shift, maintains an acid base balance between the RBC's and plasma.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Chloride shift is the movement of chloride ions ($C{l}^{-}$) into red blood cells. Carbon dioxide reacts with water to form carbonic acid in the red blood cells. The carbonic acid then dissociates into hydrogen carbonate ions ($HC{O}_3$) and hydrogen ions (H+). The plasma membrane is relatively permeable to negative ions. Therefore, the hydrogen carbonate ions diffuse out of the cell into the plasma, leaving the hydrogen ions, which create a net positive charge; this is neutralised by the diffusion of chloride ions from the plasma into the cell.

So, the correct answer is 'Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion'.