Biology - Structural Organisation in Animals Question with Solution | TestHub

The alveolar wall is the primary site for the exchange of gases in the lungs.

For efficient diffusion of oxygen and carbon dioxide, the diffusion boundary must be extremely thin.

Therefore, the alveolar wall is composed of a single layer of flattened cells with irregular boundaries, which is known as simple squamous epithelium.

This squamous epithelium rests on a thin basement membrane of connective tissue.

Answer: Squamous