Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. Clarification Statement: Emphasis is on functions at the organism sy stem lev el such as nutrient uptake, water delivery , and organism movement in response to neural stimuli. A n example of an interacting sy stem could be an artery depending on the proper function of elastic tissue and smooth muscle to regulate and deliv er the proper amount of blood within the circulatory system. Assessment Boundary: Assessment does not include interactions and functions at the molecular or chemical reaction level.