Gas exchange of oxygen and carbon dioxide takes place in the alveoli . Oxygen from the inhaled air diffuses through the walls of the alveoli and adjacent capillaries into the red blood cells . The oxygen is then carried by the blood to the body tissues . They are surrounded by numerous capillaries
Evolution does not occur in a straight line with one species another in a series of orderly steps with living species that are closely related share a common trait. I hope my answer has come to your help. God bless and have a nice day ahead!
