Question

Assertion :

In the alveoli, dissociation of $C{O}_2$ from carbamino-haemoglobin takes place.

Reason: In the alveoli $P_{c{o}_2}$ is low and $P_{o_2}$ is high

• 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 A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Haemoglobin can bind with both O${}_2$ and CO${}_2$. Haemoglobin binds with oxygen to form oxyhemoglobin and with CO${}_2$ to form carbaminohaemoglobin. The molecule to which it's going to bind depends on partial pressure i.e. it binds to the molecule with higher partial pressure. In the alveoli P${}_O$${}_2$ is high compared to P${}_C$${}_O$${}_2$, hence carbamino-haemoglobin dissociate to release CO${}_2$ and bind with O${}_2$.

Here, both assertion and reason are correct statements and reason is the correct explanation for the assertion.

So, the correct option is 'A'.