Question

Match the following columns and select the correct option:

Column - I	Column - II
(a)	Pneumotaxic centre	(i)	Alveoli
(b)	$O_2$dissociation curve	(ii)	Pons region of brain
(c)	Carbonic anhydrase	(iii)	Haemoglobin
(d)	Primary site of exchange of gases	(iv)	R.B.C.

• A. $\left(a\right)-\left(i\right),\left(b\right)-\left(iii\right),\left(c\right)-\left(ii\right),\left(d\right)-\left(iv\right)$
• B. $\left(a\right)-\left(ii\right),\left(b\right)-\left(iii\right),\left(c\right)-\left(iv\right),\left(d\right)-\left(i\right)$
• C. $\left(a\right)-\left(iii\right),\left(b\right)-\left(ii\right),\left(c\right)-\left(iv\right),\left(d\right)-\left(i\right)$
• D. $\left(a\right)-\left(iv\right),\left(b\right)-\left(i\right),\left(c\right)-\left(iii\right),\left(d\right)-\left(ii\right)$

Answer 1

The correct option is B $\left(a\right)-\left(ii\right),\left(b\right)-\left(iii\right),\left(c\right)-\left(iv\right),\left(d\right)-\left(i\right)$

The pneumotaxic centre is located in the superior part of the pons (present in the brain). It helps in moderating the functions of the respiratory rhythm centre present in the medulla.

The oxygen dissociation curve is a sigmoid curve obtained when percentage saturation of haemoglobin with $O_2$ is plotted against the pO2 .

Carbonic anhydrase enzyme is present in RBC and it facilitates the formation of carbonic acid during the transport of $C{O}_2$.

Alveoli are the structural and functional units of the lungs where the gaseous exchange takes place between blood and the alveolar air.

Hence, option b is correct.