gas exchange occurs between pulmonary capillaries and the alveoli in the lungs.
Initially within the alveoli inside the lungs; also between the body's tissue cells and blood
When the partial pressure between the alveoli and the blood, or between the blood and the tissues, is different - i.e. when a concentration gradient exists.
The air space keeps the stomata moist so that transpiration and gas exchange can occur. The gas exchange in the stomata needs to take place so that photosynthesis can occur. So without the air space you have no stomata, and without the stomata you have no photosynthesis which is how plants obtain their food.
Respiration is a process of gas exchange. Respiration is necessary to supply cells with oxygen for metabolism and to remove the waste by product carbon dioxide.
The capillaries are responsible for gas and nutrient exchange with each of the body's cells.
The gas occurs by simple diffusion through the cells.
gills
the alveolus
in the leaf
in the leave
gas exchange occurs between pulmonary capillaries and the alveoli in the lungs.
gas exchange occurs between the thin walls of the alveoli and the thin walls of the capillaries
in their gills.
In the alveoli
lungs
--it is in the alveoli where the exchange of gases occur.. :))