Question

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: During the transportation of gases, about 20-25 percent of \(CO_2\) is carried by Haemoglobin as carbamino-haemoglobin.
Reason R: This binding is related to high p \(CO_2\) and low p \(O_2\) in tissues.
In the light of the above statements, choose the correct answer from the options given below

• A. A is true but R is false
• B. A is false but R is true
• C. Both A and R are true and R is the correct explanation of A.
• D. Both A and R are true but R is NOT the correct explanation of A.

Answer 1

The Correct Option is C

The given question comprises an assertion and a reason related to the transportation of gases in the human body, specifically the role of haemoglobin in carrying carbon dioxide (\(CO_2\)). Let's analyze the statements:

Assertion A: During the transportation of gases, about 20-25 percent of \(CO_2\) is carried by Haemoglobin as carbamino-haemoglobin.

Reason R: This binding is related to high partial pressure of \(CO_2\) (p \(CO_2\)) and low partial pressure of \(O_2\) (p \(O_2\)) in tissues.

Analysis:

1. Understanding Assertion A: Haemoglobin is not only responsible for transporting oxygen (\(O_2\)) but also a significant portion of carbon dioxide (\(CO_2\)) from the tissues back to the lungs. Approximately 20-25% of \(CO_2\) is bound to haemoglobin, forming carbamino-haemoglobin. This assertion is scientifically correct as it accurately describes the function of haemoglobin in \(CO_2\) transport.
2. Understanding Reason R: The binding of \(CO_2\) to haemoglobin is facilitated under conditions where there is a high concentration of carbon dioxide (high p \(CO_2\)) which is typical in tissues where cellular respiration occurs. Simultaneously, the oxygen concentration is lower (low p \(O_2\)) in these regions because oxygen is being utilized. This creates an optimal condition for \(CO_2\) binding to haemoglobin. This reason is correct and explains the physiological conditions under which carbamino-haemoglobin is formed.

Conclusion: Both the assertion and the reason are true. Furthermore, the reason provided (R) correctly explains why the assertion (A) occurs, as high \(CO_2\) levels and low \(O_2\) levels in tissues promote the formation of carbamino-haemoglobin. Hence, the correct answer is:

Both A and R are true and R is the correct explanation of A.