Essential knowledge 2.A.1: All living systems require constant input of free energy.

f. Changes in free energy availability can result in disruptions to an ecosystem.
      To foster student understanding of this concept, instructors can choose an illustrative example such as:
         •  Change in the producer level can affect the number and size of other trophic levels
         •  Change in energy resources levels such as sunlight can affect the number and size of the trophic levels

LO 2.2 The student is able to justify a scientific claim that free energy is required for living systems to maintain organization, to grow or to reproduce, but that multiple strategies exist in different living systems. [See SP 6.1]

LO 2.3 The student is able to predict how changes in free energy availability affect organisms, populations and ecosystems. [See SP 6.4]

Essential knowledge 2.A.3: Organisms must exchange matter with the environment to grow, reproduce and maintain organization.

        a. Molecules and atoms from the environment are necessary to build new molecules.
          Evidence of student learning is a demonstrated understanding of each of the following:
           1. Carbon moves from the environment to organisms where it is used to build carbohydrates, proteins, lipids or nucleic acids.
                 Carbon is used in storage compounds and cell formation in all organisms.

              2. Nitrogen moves from the environment to organisms where it is used in building proteins and nucleic acids. Phosphorus moves from the
                   environment to organisms where it is used in nucleic acids and certain lipids.

LO 2.9 The student is able to represent graphically or model quantitatively the exchange of molecules between an organism and its environment, and the subsequent use of these molecules to build new molecules that facilitate dynamic homeostasis, growth and reproduction. [See SP 1.1, 1.4]

Enduring understanding 2.D: Growth and dynamic homeostasis of a biological system are influenced by changes in the system's environment

Learning Objectives:
LO 2.22 The student is able to refine scientific models and questions about the effect of complex biotic and abiotic interactions on all biological systems, from cells and organisms to populations, communities and ecosystems. [See SP 1.3, 3.2]

LO 2.23 The student is able to design a plan for collecting data to show that all biological systems (cells, organisms, populations, communities and ecosystems) are affected by complex biotic and abiotic interactions. [See SP 4.2, 7.2]

LO 2.24 The student is able to analyze data to identify possible patterns and relationships between a biotic or abiotic factor and a biological system (cells, organisms, populations, communities or ecosystems). [See SP 5.1]

Learning Objective:
LO 2.28 The student is able to use representations or models to analyze quantitatively and qualitatively the effects of disruptions to dynamic homeostasis in biological systems. [See SP 1.4]

 Learning Objectives:
LO 2.38 The student is able to analyze data to support the claim that responses to information and communication of information affect natural selection. [See SP 5.1]

LO 2.39 The student is able to justify scientific claims, using evidence, to describe how timing and coordination of behavioral events in organisms are regulated by several mechanisms. [See SP 6.1]

LO 2.40 The student is able to connect concepts in and across domain(s) to predict how environmental factors affect responses to information and change behavior. [See SP 7.2]

Learning Objectives:
LO 3.40 The student is able to analyze data that indicate how organisms exchange information in response to internal changes and external cues, and which can change behavior. [See SP 5.1]

LO 3.41 The student is able to create a representation that describes how organisms exchange information in response to internal changes and external cues, and which can result in changes in behavior. [See SP 1.1]

LO 3.42 The student is able to describe how organisms exchange information in response to internal changes or environmental cues. [See SP 7.1]

Essential knowledge 4.A.5: Communities are composed of populations of organisms that interact in complex ways.

          a. The structure of a community is measured and described in terms of species composition and species diversity.

          b. Mathematical or computer models are used to illustrate and investigate population interactions within and environmental impacts on a
               community. [See also 3.E.1]
             To foster student understanding of this concept, instructors can choose an illustrative example such as:
               •  Predator/prey relationships spreadsheet model
             •  Symbiotic relationship
               •  Graphical representation of field data
               •  Introduction of species
               •  Global climate change models

          c. Mathematical models and graphical representations are used to illustrate population growth patterns and interactions.
               Evidence of student learning is a demonstrated understanding of each of the following:
                    1. Reproduction without constraints results in the exponential growth of a population.

                         2. A population can produce a density of individuals that exceeds the system's resource availability.

                         3. As limits to growth due to density-dependent and density- independent factors are imposed, a logistic growth model generally
                              ensues.

                         4. Demographics data with respect to age distributions and fecundity can be used to study human populations.

Learning Objectives:
LO 4.11 The student is able to justify the selection of the kind of data needed to answer scientific questions about the interaction of populations within communities. [See SP 1.4, 4.1]

LO 4.12 The student is able to apply mathematical routines to quantities that describe communities composed of populations of organisms that interact in complex ways. [See SP 2.2]

LO 4.13 The student is able to predict the effects of a change in the community's populations on the community. [See SP 6.4]


Essential knowledge 4.A.6: Interactions among living systems and with their environment result in the movement of matter and energy.

          a. Energy flows, but matter is recycled. [See also 2.A.1]

          b. Changes in regional and global climates and in atmospheric composition influence patterns of primary productivity.

          c. Organisms within food webs and food chains interact. [See also 2.D.1]

          d. Food webs and food chains are dependent on primary productivity.

          e. Models allow the prediction of the impact of change in biotic and abiotic factors.
                 Evidence of student learning is a demonstrated understanding of each of the following
                1. Competition for resources and other factors limits growth and can be described by the logistic model.

                    2. Competition for resources, territoriality, health, predation, accumulation of wastes and other factors contribute to density-
                        dependent population regulation.

          f. Human activities impact ecosystems on local, regional and global scales. [See also 2.D.3]
              Evidence of student learning is a demonstrated understanding of each of the following:
                   1. As human populations have increased in numbers, their impact on habitats for other species have been magnified.

                        2. In turn, this has often reduced the population size of the affected species and resulted in habitat destruction and, in some cases,
                            the extinction of species.

           g. Many adaptations of organisms are related to obtaining and using energy and matter in a particular environment. [See also 2.A.1, 2.A.2]

Essential knowledge 4.B.3: Interactions between and within populations influence patterns of species distribution and abundance.

          a. Interactions between populations affect the distributions and abundance of populations.
              Evidence of student learning is a demonstrated understanding of each of the following:
                  1. Competition, parasitism, predation, mutualism and commensalism can affect population dynamics.

                  2. Relationships among interacting populations can be characterized by positive and negative effects, and can be modeled
                       mathematically (predator/prey, epidemiological models, invasive species).

                  3. Many complex symbiotic relationships exist in an ecosystem, and feedback control systems play a role in the functioning of
                      these ecosystems.
                 ✘✘ Specific symbiotic interactions are beyond the scope of  the course and the AP Exam

          b. A population of organisms has properties that are different from those of the individuals that make up the population. The cooperation and
               competition between individuals contributes to these different properties.

          c. Species-specific and environmental catastrophes, geological events, the sudden influx/depletion of abiotic resources or increased human
               activities affect species distribution and abundance. [See also 1.A.1, 1.A.2]

               To foster student understanding of this concept, instructors can choose an illustrative example such as:
                •  Loss of keystone species
              •  Kudzu
              •  Dutch elm disease

Learning Objective:
LO 4.19 The student is able to use data analysis to refine observations and measurements regarding the effect of population interactions on patterns of species distribution and abundance. [See SP 5.2]

Essential knowledge 4.B.4: Distribution of local and global ecosystems changes over time.

         a. Human impact accelerates change at local and global levels. [See also 1.A.2]
            To foster student understanding of this concept, instructors can choose an illustrative example such as:
              •  Logging, slash and burn agriculture, urbanization, monocropping, infrastructure development (dams, transmission lines, roads), and
                         global climate change threaten ecosystems and life on Earth.
              •  An introduced species can exploit a new niche free of predators or competitors, thus exploiting new resources.
              •  Introduction of new diseases can devastate native species.
                      Illustrative examples include:
                   •  Dutch elm disease
                   •  Potato blight
                      •  Small pox [historic example for Native Americans]

             b. Geological and meteorological events impact ecosystem distribution.
               Evidence of student learning is a demonstrated understanding of the following:
                   1. Biogeographical studies illustrate these changes.
                       To foster student understanding of this concept, instructors can choose an illustrative example such as:
                    •  El Niño
                    •  Continental drift
                    •  Meteor impact on dinosaurs

 Learning Objectives:
LO 4.20 The student is able to explain how the distribution of ecosystems changes over time by identifying large-scale events that have resulted in these changes in the past. [See SP 6.3]

LO 4.21 The student is able to predict consequences of human actions on both local and global ecosystems. [See SP 6.4]

Enduring understanding 4.C: Naturally occurring diversity among and between components within biological systems affects interactions with the environment.

Essential knowledge 4.C.3: The level of variation in a population affects population dynamics.

          a. Population ability to respond to changes in the environment is affected by genetic diversity. Species and populations with little genetic
              diversity are at risk for extinction. [See also 1.A.1, 1.A.2, 1.C.1]
                 To foster student understanding of this concept, instructors can choose an illustrative example such as:
              •  California condors
                •  Black-footed ferrets
              •  Prairie chickens
                •  Potato blight causing the potato famine
                        • Corn rust affects on agricultural crops
                •  Tasmanian devils and infectious cancer