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 trachea is shaped like a pipe. When a person breathes in, the trachea filters the air down into the bronchi, two air tubes that then carry air directly to the lungs. The main organs of the respiratory system are the lungs. They take oxygen into the body and breathe out carbon dioxide. Oxygen is retrieved from the lungs by red blood cells that then carry the oxygen throughout the body to the cells that need it.