Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. It occurs in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.
the baby is not theirs because the father has a blood type of OB so he can give an O or a B and the mother has a blood type AB so she can give either an A or a B so their child could either be of blood type A or B or AB but not O
