TABLE 3.

Examples of complex biological phenomena^a

Complex biological phenomenon	Core concepts	Conceptual elements
Homeostatic regulation of blood glucose levels	Information flow, exchange, and storage; pathways and transformations of energy and matter; and systems	IFES4: Information from the environment regulates protein synthesis and activity, which control cellular processes and thereby organismal and population-level activity.
		PTEM5: Biological entities regulate the synthesis, storage, and mobilization of biological compounds to meet energy demands.
		S2: Changes in one component of a biological system can affect or be regulated by other components of the same system.
Countercurrent gas exchange in fish	Structure and function; information flow, exchange, and storage; and systems	SF2: Individual structures can be arranged into organized units whose emergent properties enable more complex functions.
		IFES3: The genetic code regulates the process of protein synthesis and determines the structure and function of proteins.
		S2: Changes in one component of a biological system can affect or be regulated by other components of the same system.
Coevolution of the symbiotic relationship among three-toed sloths, pyralid moths, and green algae	Evolution; systems; and pathways and transformations of energy and matter	E6: Populations are composed of individual organisms that vary in their fitness, leading to differential rates of survival and reproduction and, therefore, changes in allele frequency over time.
		S2: Changes in one component of a biological system can affect or be regulated by other components of the same system.
		PTEM4: Matter is recycled through the rearrangement of chemical bonds by biological entities.

^aEach example includes elements from multiple concepts. The conceptual elements can be used to dissect the complexity in order to assess student understanding of the components and the connections between components.