NEET 1990 · Class 11

Breathing and Exchange of Gases

The alveolar epithelium in the lung is

  1. (A)nonciliated columnar
  2. (B)nonciliated squamous
  3. (C)ciliated columnar
  4. (D)ciliated squamous

The NCERT line that answers it

Verbatim line

The wall of the alveolus is a 'Squamous epithelium of alveolar wall (one-celled thick)'.

Chapter
Breathing and Exchange of Gases
Section
14.3 EXCHANGE OF GASES

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 'Squamous epithelium of alveolar wall' which directly identifies the epithelium type as squamous, and the context shows it's part of the alveolar wall where gas exchange occurs, implying it's nonciliated for efficient diffusion.

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Question text is reproduced from the published NEET 1990 paper for study and commentary. NCERT text is quoted, not redistributed; textbooks remain at ncert.nic.in. Our mapping method, including its measured error rates, is published at /methodology.