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:Human approach, attitudes and adherence to the safety skills does deal with the impact over environmental factors at a personal level. We have to be more careful and cautious while we pursue our own habits, and activities, with the aim of posing less harm to the environment in any way.
Explanation:
This definition above refers to the geographic isolation.
It means exactly what it says in the definition - one species is left behind from the rest of the population, and it stays in that particular location, evolving and changing from the species and population it was once a part of.
The answer is, "B", "Ribosomal RNA".