In lungs, the air is separated from the venous blood through

(A)transitional epithelium + tunica externa of blood vessel
(B)squamous epithelium + endothelium of blood vessel
(C)squamous epithelium + tunica media of blood vessel
(D)none of the above

The NCERT line that answers it

Verbatim line

The diffusion membrane is made up of three major layers (Figure 14.4) namely, the thin squamous epithelium of alveoli, the endothelium of alveolar capillaries and the basement substance (composed of a thin basement membrane supporting the squamous epithelium and the basement membrane surrounding the single layer endothelial cells of capillaries) in between them.

Chapter: Breathing and Exchange of Gases
Section: 14.3 EXCHANGE OF GASES
Page: 7
Words matched: 53 of 53

The answer appears as a continuous sentence in NCERT. This is that sentence.

How this line gives the answer

0, emb=1.0, combined=1.0). Verified: high — The span explicitly states that the diffusion membrane consists of 'the thin squamous epithelium of alveoli' and 'the endothelium of alveolar capillaries', which directly matches option B's 'squamous epithelium + endothelium of blood vessel'.

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