Answer:
Gas exchange occurs at two sites in the body: in the lungs, where oxygen is picked up and carbon dioxide is released at the respiratory membrane, and at the tissues, where oxygen is released and carbon dioxide is picked up.
Explanation:
Answer:
D
Explanation:
It is often like this: cell->tissue->organ->system
Everything. DNA contains genes In which in a person determines proteins how much protein is formed is based on how strong the trait is. <span>DNA also determines every genetic trait an organism has.DNA's main role is to store information.</span>
