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.
Just as the organs in an organ system work together to accomplish their task, so the different organ systems also cooperate to keep the body running. For example, the respiratory system and the circulatory system work closely together to deliver oxygen to cells and to get rid of the carbon dioxide the cells produce. The circulatory system picks up oxygen in the lungs and drops it off in the tissues, then performs the reverse service for carbon dioxide.