Question: 100% NCERT covered from Particular Keyword.Explanations are 100% from NCERT | [Difficult level: Easy] From NCERT NEET Derived Question.

Although much CO2 is carried in blood, yet blood does not

become acidic, because

(a) it is absorbed by the leucocytes.

(b) blood buffers play an important role in CO2 transport.

(c) it combines with water to form H2CO3which is

neutralized by NaCO3.

(d) it is continuously diffused through tissues and is not

allowed to accumulate.

Answer: b

👉TRANSPORT OF GASES

👉Blood is the medium of transport for O2 and CO2. About 97 per cent of O2 is

transported by RBCs in the blood. The remaining 3 per cent of O2 is carried

in a dissolved state through the plasma. Nearly 20-25 per cent of CO2 is

transported by RBCs whereas 70 per cent of it is carried as bicarbonate.

About 7 per cent of CO2 is carried in a dissolved state through plasma.

👉RBCs contain

a very high concentration of the enzyme, carbonic anhydrase and minute

quantities of the same is present in the plasma too. This enzyme facilitates

the following reaction in both directions.

👉

👉At the tissue site where partial pressure of CO2 is high due to

catabolism, CO2 diffuses into blood (RBCs and plasma) and forms HCO3–

and H+,.

👉Thus,

CO2 trapped as bicarbonate at the tissue level and transported to the

alveoli is released out as CO2

👉

Although much CO