Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Tubular secretion is an important step in urine formation as it helps in the maintenance of ionic and acid-base balance of body fluids. Reason (R): The cells of the proximal and distal convoluted tubules selectively secrete H ⁺ , K ⁺ and ammonia into the filtrate. In the light of the above statemen

Step-by-step solution

Assertion (A) is a correct statement. During urine formation, tubular secretion is a crucial step because it directly contributes to the maintenance of the ionic and acid-base balance of body fluids. Reason (R) is also a correct statement. The proximal convoluted tubule (PCT) and distal convoluted tubule (DCT) actively secrete specific ions such as H ⁺ , K ⁺ , and ammonia into the filtrate. Reason (R) correctly explains Assertion (A) because the selective secretion of hydrogen ions ( H ⁺ ) and ammonia regulates the