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.
How the excretoryand the respiratory system work together. The excretory system helps the respiratory system by geting rid of carbon dioxide. The respiratory system helps the excretory system by getting rid of CO2 from the body.