The main function of the respiratory system is to allow the exchange of gases between the atmosphere and the lungs.
Hence,the only structure that carries out this function is the alveoli as other structures such as the nose,trachea and pharynx transport gases to the alveoli just so that it can can out its function.
Answer:
A dominant trait is a trait that overpowers, a recessive trait is more rare.
Explanation:
Dominant traits are the most common trait in a pair. They will be seen the most often in offspring. Recessive traits are usually repressed traits that the parents had that were not previously visible
I think you're looking for Cellular differentiation