Truly modern molecular biology emerged with the uncovering of the structure of DNA in the 1960s and concurrent advances in biochemistry and genetics. Molecular biology is one of three primary molecular-scale biological sciences, the others being biochemistry and genetics.
1 Students should know the parts and functions of the circulatory and respiratory systems and how they work together for respiration. 2  Students should also understand what homeostasis is and that all living things must be able to maintain homeostasis.
The main job of the Respiratory System is to provide the blood with oxygen, so the rest of the body can get oxygen too. The body does this by breathing. Our body breathes in oxygen, and breathes out carbon dioxide. By changing these gases in our bodies, the blood gets oxygen. Molecules of oxygen and carbon dioxide are passively exchanged.