The function of surfactant is/are:

Which structure in humans is analogous to the spiracles of a cockroach?

Given below are two statements regarding the respiratory system of man.
$Statement-I$: Epiglottis prevents the entry of food into the trachea.
$Statement-II$: The internal lining of the trachea is made up of ciliated epithelium only.
In the light of the above statements, choose the most appropriate answer from the options given below:

The total surface area of the alveoli in human lungs is approximately: (in $, m^2$)

Because of....... the layer of epithelial cells in the stomach of chordates is not damaged.

The gaseous exchange between blood and air does not occur in