The respiratory system of insects is called:

In large organisms, such as humans, the ratio of surface area to volume is:

The most numerous cells in the epithelium of the bronchus and bronchioles are called:

The branchioles end in millions of tiny interconnected cavities called:

The water proof layer that protects human skin.

The respiratory organ of fish is called:

Carbon dioxide and oxygen diffuse in and out of leaves through small openings called:

The part of the leaf of a terrestrial plant on which stomatal opening is seen:

Which part of the organism across around which the gas exchange takes place ?

Write the name of the process of stomatal opening and closure.