NGSS High School Life Sciences Evidence Statements

HS-LS1-1

Students who demonstrate understanding can:

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.

Assessment Boundary: Assessment does not include identification of specific cell or tissue types, whole body systems, specific protein structures and functions, or the biochemistry of protein synthesis.

Science and Engineering Practices

Constructing Explanations and Designing Solutions

Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.

Disciplinary Core Ideas

LS1.A: Structure and Function

Crosscutting Concepts

Structure and Function

Observable features of the student performance by the end of the course:

  1. Articulating the explanation of phenomena

    • a. Students construct an explanation that includes the idea that regions of DNA called genes determine the structure of proteins, which carry out the essential functions of life through systems of specialized cells.

  2. Evidence

    • a. Students identify and describe* the evidence to construct their explanation, including that:

      • i. All cells contain DNA;

      • ii. DNA contains regions that are called genes;

      • iii. The sequence of genes contains instructions that code for proteins; and

      • iv. Groups of specialized cells (tissues) use proteins to carry out functions that are essential to the organism.

    • b. Students use a variety of valid and reliable sources for the evidence (e.g., theories, simulations, peer review, students’ own investigations).

  3. Reasoning

    • a. Students use reasoning to connect evidence, along with the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future, to construct the explanation. Students describe* the following chain of reasoning in their explanation:

      • i. Because all cells contain DNA, all cells contain genes that can code for the formation of proteins.

      • ii. Body tissues are systems of specialized cells with similar structures and functions, each of whose functions are mainly carried out by the proteins they produce.

      • iii. Proper function of many proteins is necessary for the proper functioning of the cells.

      • iv. Gene sequence affects protein function, which in turn affects the function of body tissues.

HS-LS1-2

Students who demonstrate understanding can:

Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms.

Assessment Boundary: Assessment does not include interactions and functions at the molecular or chemical reaction level.

Science and Engineering Practices

Developing and Using Models

Modeling in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed worlds.

Disciplinary Core Ideas

LS1.A: Structure and Function

Crosscutting Concepts

Systems and System Models

Observable features of the student performance by the end of the course:

  1. Components of the model

    • a. Students develop a model in which they identify and describe* the relevant parts (e.g., organ system, organs, and their component tissues) and processes (e.g., transport of fluids, motion) of body systems in multicellular organisms.

  2. Relationships

    • a. In the model, students describe* the relationships between components, including:

      • i. The functions of at least two major body systems in terms of contributions to overall function of an organism;

      • ii. Ways the functions of two different systems affect one another; and

      • iii. A system’s function and how that relates both to the system’s parts and to the overall function of the organism.

  3. Connections

    • a. Students use the model to illustrate how the interaction between systems provides specific functions in multicellular organisms.

    • b. Students make a distinction between the accuracy of the model and actual body systems and functions it represents.

HS-LS1-3

Students who demonstrate understanding can:

Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.

Clarification Statement: Examples of investigations could include heart rate response to exercise, stomate response to moisture and temperature, and root development in response to water levels.

Assessment Boundary: Assessment does not include the cellular processes involved in the feedback mechanism.

Science and Engineering Practices

Planning and Carrying Out Investigations

Planning and carrying out investigations in 9- 12 builds on K-8 experiences and progresses to include investigations that provide evidence for and test conceptual, mathematical, physical, and empirical models.

Connections to Nature of Science

Scientific Investigations Use a Variety of Methods

Disciplinary Core Ideas

LS1.A: Structure and Function

Crosscutting Concepts

Stability and Change

Observable features of the student performance by the end of the course:

  1. Identifying the phenomenon under investigation

    • a. Students describe* the phenomenon under investigation, which includes the following idea: that feedback mechanisms maintain homeostasis.

  2. Identifying the evidence to answer this question

    • a. Students develop an investigation plan and describe* the data that will be collected and the evidence to be derived from the data, including:

      • i. Changes within a chosen range in the external environment of a living system; and

      • ii. Responses of a living system that would stabilize and maintain the system’s internal conditions (homeostasis), even though external conditions change, thus establishing the positive or negative feedback mechanism.

    • b. Students describe* why the data will provide information relevant to the purpose of the investigation.

  3. Planning for the investigation

    • a. In the investigation plan, students describe*:

      • i. How the change in the external environment is to be measured or identified;

      • ii. How the response of the living system will be measured or identified;

      • iii. How the stabilization or destabilization of the system’s internal conditions will be measured or determined;

      • iv. The experimental procedure, the minimum number of different systems (and the factors that affect them) that would allow generalization of results, the evidence derived from the data, and identification of limitations on the precision of data to include types and amounts; and

      • v. Whether the investigation will be conducted individually or collaboratively.

  4. Collecting the data

    • a. Students collect and record changes in the external environment and organism responses as a function of time.

  5. Refining the design

    • a. Students evaluate their investigation, including:

      • i. Assessment of the accuracy and precision of the data, as well as limitations (e.g., cost, risk, time) of the investigation, and make suggestions for refinement; and

      • ii. Assessment of the ability of the data to provide the evidence required.

    • b. If necessary, students refine the investigation plan to produce more generalizable data.

HS-LS1-4

Students who demonstrate understanding can:

Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.

Assessment Boundary: Assessment does not include specific gene control mechanisms or rote memorization of the steps of mitosis.

Science and Engineering Practices

Developing and Using Models

Modeling in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed worlds.

Disciplinary Core Ideas

LS1.B: Growth and Development of Organisms

Crosscutting Concepts

Systems and System Models

Observable features of the student performance by the end of the course:

  1. Components of the model

    • a. From the given model, students identify and describe* the components of the model relevant for illustrating the role of mitosis and differentiation in producing and maintaining complex organisms, including:

      • i. Genetic material containing two variants of each chromosome pair, one from each parent;

      • ii. Parent and daughter cells (i.e., inputs and outputs of mitosis); and

      • iii. A multi-cellular organism as a collection of differentiated cells.

  2. Relationships

    • a. Students identify and describe* the relationships between components of the given model, including:

      • i. Daughter cells receive identical genetic information from a parent cell or a fertilized egg.

      • ii. Mitotic cell division produces two genetically identical daughter cells from one parent cell.

      • iii. Differences between different cell types within a multicellular organism are due to gene expression — not different genetic material within that organism.

  3. Connections

    • a. Students use the given model to illustrate that mitotic cell division results in more cells that:

      • i. Allow growth of the organism;

      • ii. Can then differentiate to create different cell types; and

      • iii. Can replace dead cells to maintain a complex organism.

    • b. Students make a distinction between the accuracy of the model and the actual process of cellular division.

HS-LS1-5

Students who demonstrate understanding can:

Use a model to illustrate how photosynthesis transforms light energy into stored chemical energy.

Clarification Statement: Emphasis is on illustrating inputs and outputs of matter and the transfer and transformation of energy in photosynthesis by plants and other photosynthesizing organisms. Examples of models could include diagrams, chemical equations, and conceptual models.

Assessment Boundary: Assessment does not include specific biochemical steps.

Science and Engineering Practices

Developing and Using Models

Modeling in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed worlds.

Disciplinary Core Ideas

LS1.C: Organization for Matter and Energy Flow in Organisms

Crosscutting Concepts

Energy and Matter

Observable features of the student performance by the end of the course:

  1. Components of the model

    • a. From the given model, students identify and describe* the components of the model relevant for illustrating that photosynthesis transforms light energy into stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen, including:

      • i. Energy in the form of light;

      • ii. Breaking of chemical bonds to absorb energy;

      • iii. Formation of chemical bonds to release energy; and

      • iv. Matter in the form of carbon dioxide, water, sugar, and oxygen.

  2. Relationships

    • a. Students identify the following relationship between components of the given model: Sugar and oxygen are produced by carbon dioxide and water by the process of photosynthesis.

  3. Connections

    • c. Students use the given model to illustrate:

      • i. The transfer of matter and flow of energy between the organism and its environment during photosynthesis; and

      • ii. Photosynthesis as resulting in the storage of energy in the difference between the energies of the chemical bonds of the inputs (carbon dioxide and water) and outputs (sugar and oxygen).

HS-LS1-6

Students who demonstrate understanding can:

Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.

Clarification Statement: Emphasis is on using evidence from models and simulations to support explanations.

Science and Engineering Practices

Constructing Explanations and Designing Solutions

Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.

Disciplinary Core Ideas

LS1.C: Organization for Matter and Energy Flow in Organisms

Crosscutting Concepts

Energy and Matter

Observable features of the student performance by the end of the course:

  1. Articulating the explanation of phenomena

    • a. Students construct an explanation that includes:

      • i. The relationship between the carbon, hydrogen, and oxygen atoms from sugar molecules formed in or ingested by an organism and those same atoms found in amino acids and other large carbon-based molecules; and

      • ii. That larger carbon-based molecules and amino acids can be a result of chemical reactions between sugar molecules (or their component atoms) and other atoms.

  2. Evidence

    • a. Students identify and describe* the evidence to construct the explanation, including:

      • i. All organisms take in matter (allowing growth and maintenance) and rearrange the atoms in chemical reactions.

      • ii. Cellular respiration involves chemical reactions between sugar molecules and other molecules in which energy is released that can be used to drive other chemical reactions.

      • iii. Sugar molecules are composed of carbon, oxygen, and hydrogen atoms.

      • iv. Amino acids and other complex carbon-based molecules are composed largely of carbon, oxygen, and hydrogen atoms.

      • v. Chemical reactions can create products that are more complex than the reactants.

      • vi. Chemical reactions involve changes in the energies of the molecules involved in the reaction.

    • b. Students use a variety of valid and reliable sources for the evidence (e.g., theories, simulations, students’ own investigations).

  3. Reasoning

    • a. Students use reasoning to connect the evidence, along with the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future, to construct the explanation that atoms from sugar molecules may combine with other elements via chemical reactions to form other large carbon-based molecules. Students describe* the following chain of reasoning for their explanation:

      • i. The atoms in sugar molecules can provide most of the atoms that comprise amino acids and other complex carbon-based molecules.

      • ii. The energy released in respiration can be used to drive chemical reactions between sugars and other substances, and the products of those reactions can include amino acids and other complex carbon-based molecules.

      • iii. The matter flows in cellular processes are the result of the rearrangement of primarily the atoms in sugar molecules because those are the molecules whose reactions release the energy needed for cell processes.

  4. Revising the explanation

    • a. Given new evidence or context, students revise or expand their explanation about the relationships between atoms in sugar molecules and atoms in large carbon-based molecules, and justify their revision.

HS-LS1-7

Students who demonstrate understanding can:

Use a model to illustrate that cellular respiration is a chemical process whereby the bonds of food molecules and oxygen molecules are broken and the bonds in new compounds are formed resulting in a net transfer of energy.

Clarification Statement: Emphasis is on the conceptual understanding of the inputs and outputs of the process of cellular respiration.

Assessment Boundary: Assessment should not include identification of the steps or specific processes involved in cellular respiration.

Science and Engineering Practices

Developing and Using Models

Modeling in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed worlds.

Disciplinary Core Ideas

LS1.C: Organization for Matter and Energy Flow in Organisms

Crosscutting Concepts

Energy and Matter

Observable features of the student performance by the end of the course:

  1. Components of the model

    • a. From a given model, students identify and describe* the components of the model relevant for their illustration of cellular respiration, including:

      • i. Matter in the form of food molecules, oxygen, and the products of their reaction (e.g., water and CO2);

      • ii. The breaking and formation of chemical bonds; and

      • iii. Energy from the chemical reactions.

  2. Relationships

    • a. From the given model, students describe* the relationships between components, including:

      • i. Carbon dioxide and water are produced from sugar and oxygen by the process of cellular respiration; and

      • ii. The process of cellular respiration releases energy because the energy released when the bonds that are formed in CO2 and water is greater than the energy required to break the bonds of sugar and oxygen.

  3. Connections

    • a. Students use the given model to illustrate that:

      • i. The chemical reaction of oxygen and food molecules releases energy as the matter is rearranged, existing chemical bonds are broken, and new chemical bonds are formed, but matter and energy are neither created nor destroyed.

      • ii. Food molecules and oxygen transfer energy to the cell to sustain life’s processes, including the maintenance of body temperature despite ongoing energy transfer to the surrounding environment.

HS-LS2-1

Students who demonstrate understanding can:

Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.

Assessment Boundary: Assessment does not include deriving mathematical equations to make comparisons.

Science and Engineering Practices

Using Mathematics and Computational Thinking

Mathematical and computational thinking in 9-12 builds on K-8 experiences and progresses to using algebraic thinking and analysis; a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms; and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.

Disciplinary Core Ideas

LS2.A: Interdependent Relationships in Ecosystems

Crosscutting Concepts

Scale, Proportion, and Quantity

Observable features of the student performance by the end of the course:

  1. Representation

    • a. Students identify and describe* the components in the given mathematical and/or computational representations (e.g., trends, averages, histograms, graphs, spreadsheets) that are relevant to supporting given explanations of factors that affect carrying capacities of ecosystems at different scales. The components include:

      • i. The population changes gathered from historical data or simulations of ecosystems at different scales; and

      • ii. Data on numbers and types of organisms as well as boundaries, resources, and climate.

    • b. Students identify the given explanation(s) to be supported, which include the following ideas: Factors (including boundaries, resources, climate, and competition) affect carrying capacity of an ecosystem, and:

      • i. Some factors have larger effects than do other factors.

      • ii. Factors are interrelated.

      • iii. The significance of a factor is dependent on the scale (e.g., a pond vs. an ocean) at which it occurs.

  2. Mathematical and/or computational modeling

    • a. Students use given mathematical and/or computational representations (e.g., trends, averages, histograms, graphs, spreadsheets) of ecosystem factors to identify changes over time in the numbers and types of organisms in ecosystems of different scales.

  3. Analysis

    • a. Students analyze and use the given mathematical and/or computational representations

      • i. To identify the interdependence of factors (both living and nonliving) and resulting effect on carrying capacity; and

      • ii. As evidence to support the explanation and identify the factors that have the largest effect on the carrying capacity of an ecosystem for a given population.

HS-LS2-2

Students who demonstrate understanding can:

Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.

Clarification Statement: Examples of mathematical representations include finding the average, determining trends, and using graphical comparisons of multiple sets of data.

Assessment Boundary: Assessment is limited to provided data.

Science and Engineering Practices

Using Mathematics and Computational Thinking

Mathematical and computational thinking in 9-12 builds on K-8 experiences and progresses to using algebraic thinking and analysis; a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms; and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.

Connections to Nature of Science

Scientific Knowledge is Open to Revision in Light of New Evidence

Disciplinary Core Ideas

LS2.A: Interdependent Relationships in Ecosystems
LS2.C: Ecosystem Dynamics, Functioning, and Resilience

Crosscutting Concepts

Scale, Proportion, and Quantity

Observable features of the student performance by the end of the course:

  1. Representation

    • a. Students identify and describe* the components in the given mathematical representations (which include trends, averages, and graphs of the number of organisms per unit of area in a stable system) that are relevant to supporting and revising the given explanations about factors affecting biodiversity and ecosystems, including:

      • i. Data on numbers and types of organisms are represented.

      • ii. Interactions between ecosystems at different scales are represented.

    • b. Students identify the given explanation(s) to be supported of factors affecting biodiversity and population levels, which include the following ideas:

      • i. The populations and number of organisms in ecosystems vary as a function of the physical and biological dynamics of the ecosystem.

      • ii. The response of an ecosystem to a small change might not significantly affect populations, whereas the response to a large change can have a large effect on populations that then feeds back to the ecosystem at a range of scales.

      • iii. Ecosystems can exist in the same location on a variety of scales (e.g., plants and animals vs. microbes), and these populations can interact in ways that significantly change these ecosystems (e.g., interactions among microbes, plants, and animals can be an important factor in the resources available to both a microscopic and macroscopic ecosystem).

  2. Mathematical Modeling

    • a. Students use the given mathematical representations (including trends, averages, and graphs) of factors affecting biodiversity and ecosystems to identify changes over time in the numbers and types of organisms in ecosystems of different scales.

  3. Analysis

    • a. Students use the analysis of the given mathematical representations of factors affecting biodiversity and ecosystems

      • i. To identify the most important factors that determine biodiversity and population numbers of an ecosystem.

      • ii. As evidence to support explanation(s) for the effects of both living and nonliving factors on biodiversity and population size, as well as the interactions of ecosystems on different scales.

      • iii. To describe* how, in the model, factors affecting ecosystems at one scale can cause observable changes in ecosystems at a different scale.

    • b. Students describe* the given mathematical representations in terms of their ability to support explanation(s) for the effects of modest to extreme disturbances on an ecosystems’ capacity to return to original status or become a different ecosystem.

  4. Revision

    • a. Students revise the explanation(s) based on new evidence about any factors that affect biodiversity and populations (e.g., data illustrating the effect of a disturbance within the ecosystem).

HS-LS2-3

Students who demonstrate understanding can:

Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in aerobic and anaerobic conditions.

Clarification Statement: Emphasis is on conceptual understanding of the role of aerobic and anaerobic respiration in different environments.

Assessment Boundary: Assessment does not include the specific chemical processes of either aerobic or anaerobic respiration.

Science and Engineering Practices

Constructing Explanations and Designing Solutions

Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.

Connections to Nature of Science

Scientific Knowledge is Open to Revision in Light of New Evidence

Disciplinary Core Ideas

LS2.B: Cycles of Matter and Energy Transfer in Ecosystems

Crosscutting Concepts

Energy and Matter

Observable features of the student performance by the end of the course:

  1. Articulating the explanation of phenomena

    • a. Students construct an explanation that includes that:

      • i. Energy from photosynthesis and respiration drives the cycling of matter and flow of energy under aerobic or anaerobic conditions within an ecosystem.

      • ii. Anaerobic respiration occurs primarily in conditions where oxygen is not available.

  2. Evidence

    • a. Students identify and describe* the evidence to construct the explanation, including:

      • i. All organisms take in matter and rearrange the atoms in chemical reactions.

      • ii. Photosynthesis captures energy in sunlight to create chemical products that can be used as food in cellular respiration.

      • iii. Cellular respiration is the process by which the matter in food (sugars, fats) reacts chemically with other compounds, rearranging the matter to release energy that is used by the cell for essential life processes.

    • b. Students use a variety of valid and reliable sources for the evidence, which may include theories, simulations, peer review, and students’ own investigations.

  3. Reasoning

    • a. Students use reasoning to connect evidence, along with the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future, to construct their explanation. Students describe* the following chain of reasoning used to construct their explanation:

      • i. Energy inputs to cells occur either by photosynthesis or by taking in food.

      • ii. Since all cells engage in cellular respiration, they must all produce products of respiration.

      • iii. The flow of matter into and out of cells must therefore be driven by the energy captured by photosynthesis or obtained by taking in food and released by respiration.

      • iv. The flow of matter and energy must occur whether respiration is aerobic or anaerobic.

  4. Revising the explanation

    • a. Given new data or information, students revise their explanation and justify the revision (e.g., recent discoveries of life surrounding deep sea ocean vents have shown that photosynthesis is not the only driver for cycling matter and energy in ecosystems).

HS-LS2-4

Students who demonstrate understanding can:

Use mathematical representations to support claims for the cycling of matter and flow of energy among organisms in an ecosystem.

Clarification Statement: Emphasis is on using a mathematical model of stored energy in biomass to describe the transfer of energy from one trophic level to another and that matter and energy are conserved as matter cycles and energy flows through ecosystems. Emphasis is on atoms and molecules such as carbon, oxygen, hydrogen and nitrogen being conserved as they move through an ecosystem.

Assessment Boundary: Assessment is limited to proportional reasoning to describe the cycling of matter and flow of energy.

Science and Engineering Practices

Using Mathematics and Computational Thinking

Mathematical and computational thinking in 9-12 builds on K-8 experiences and progresses to using algebraic thinking and analysis; a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms; and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.

Disciplinary Core Ideas

LS2.B: Cycles of Matter and Energy Transfer in Ecosystems

Crosscutting Concepts

Energy and Matter

Observable features of the student performance by the end of the course:

  1. Representation

    • a. Students identify and describe* the components in the mathematical representations that are relevant to supporting the claims. The components could include relative quantities related to organisms, matter, energy, and the food web in an ecosystem.

    • b. Students identify the claims about the cycling of matter and energy flow among organisms in an ecosystem.

  2. Mathematical modeling

    • a. Students describe* how the claims can be expressed as a mathematical relationship in the mathematical representations of the components of an ecosystem

    • b. Students use the mathematical representation(s) of the food web to:

      • i. Describe* the transfer of matter (as atoms and molecules) and flow of energy upward between organisms and their environment;

      • ii. Identify the transfer of energy and matter between tropic levels; and

      • iii. Identify the relative proportion of organisms at each trophic level by correctly identifying producers as the lowest trophic level having the greatest biomass and energy and consumers decreasing in numbers at higher trophic levels.

  3. Analysis

    • a. Students use the mathematical representation(s) to support the claims that include the idea that matter flows between organisms and their environment.

    • b. Students use the mathematical representation(s) to support the claims that include the idea that energy flows from one trophic level to another as well as through the environment.

    • c. Students analyze and use the mathematical representation(s) to account for the energy not transferred to higher trophic levels but which is instead used for growth, maintenance, or repair, and/or transferred to the environment, and the inefficiencies in transfer of matter and energy.

HS-LS2-5

Students who demonstrate understanding can:

Develop a model to illustrate the role of photosynthesis and cellular respiration in the cycling of carbon among the biosphere, atmosphere, hydrosphere, and geosphere.

Clarification Statement: Examples of models could include simulations and mathematical models.

Assessment Boundary: Assessment does not include the specific chemical steps of photosynthesis and respiration.

Science and Engineering Practices

Developing and Using Models

Modeling in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed world(s).

Disciplinary Core Ideas

LS2.B: Cycles of Matter and Energy Transfer in Ecosystems
PS3.D: Energy in Chemical Processes

Crosscutting Concepts

Systems and System Models

Observable features of the student performance by the end of the course:

  1. Components of the model

    • a. Students use evidence to develop a model in which they identify and describe* the relevant components, including:

      • i. The inputs and outputs of photosynthesis;

      • ii. The inputs and outputs of cellular respiration; and

      • iii. The biosphere, atmosphere, hydrosphere, and geosphere.

  2. Relationships

    • a. Students describe* relationships between components of their model, including:

      • i. The exchange of carbon (through carbon-containing compounds) between organisms and the environment; and

      • ii. The role of storing carbon in organisms (in the form of carbon-containing compounds) as part of the carbon cycle.

  3. Connections

    • a. Students describe* the contribution of photosynthesis and cellular respiration to the exchange of carbon within and among the biosphere, atmosphere, hydrosphere, and geosphere in their model.

    • b. Students make a distinction between the model’s simulation and the actual cycling of carbon via photosynthesis and cellular respiration.

HS-LS2-6

Students who demonstrate understanding can:

Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.

Science and Engineering Practices

Engaging in Argument from Evidence

Engaging in argument from evidence in 9– 12 builds on K–8 experiences and progresses to using appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about the natural and designed world(s). Arguments may also come from current scientific or historical episodes in science.

Connections to Nature of Science

Scientific Knowledge is Open to Revision in Light of New Evidence

Disciplinary Core Ideas

LS2.C: Ecosystem Dynamics, Functioning, and Resilience

Crosscutting Concepts

Stability and Change

Observable features of the student performance by the end of the course:

  1. Identifying the given explanation and the supporting claims, evidence, and reasoning.

    • a. Students identify the given explanation that is supported by the claims, evidence, and reasoning to be evaluated, and which includes the following idea: The complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.

    • b. From the given materials, students identify:

      • i. The given claims to be evaluated;

      • ii. The given evidence to be evaluated; and

      • iii. The given reasoning to be evaluated.

  2. Identifying any potential additional evidence that is relevant to the evaluation

    • a. Students identify and describe* additional evidence (in the form of data, information, or other appropriate forms) that was not provided but is relevant to the explanation and to evaluating the given claims, evidence, and reasoning:

      • i. The factors that affect biodiversity;

      • ii. The relationships between species and the physical environment in an ecosystem; and

      • iii. Changes in the numbers of species and organisms in an ecosystem that has been subject to a modest or extreme change in ecosystem conditions.

  3. Evaluating and critiquing

    • a. Students describe* the strengths and weaknesses of the given claim in accurately explaining a particular response of biodiversity to a changing condition, based on an understanding of the factors that affect biodiversity and the relationships between species and the physical environment in an ecosystem.

    • b. Students use their additional evidence to assess the validity and reliability of the given evidence and its ability to support the argument that resiliency of an ecosystem is subject to the degree of change in the biological and physical environment of an ecosystem.

    • c. Students assess the logic of the reasoning, including the relationship between degree of change and stability in ecosystems, and the utility of the reasoning in supporting the explanation of how:

      • i. Modest biological or physical disturbances in an ecosystem result in maintenance of relatively consistent numbers and types of organisms.

      • ii. Extreme fluctuations in conditions or the size of any population can challenge the functioning of ecosystems in terms of resources and habitat availability, and can even result in a new ecosystem.

HS-LS2-7

Students who demonstrate understanding can:

Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.*

Clarification Statement: Examples of human activities can include urbanization, building dams, and dissemination of invasive species.

Science and Engineering Practices

Constructing Explanations and Designing Solutions

Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.

Disciplinary Core Ideas

LS2.C: Ecosystem Dynamics, Functioning, and Resilience
LS4.D: Biodiversity and Humans
ETS1.B: Developing Possible Solutions

Crosscutting Concepts

Stability and Change

Observable features of the student performance by the end of the course:

  1. Using scientific knowledge to generate the design solution

    • a. Students design a solution that involves reducing the negative effects of human activities on the environment and biodiversity, and that relies on scientific knowledge of the factors affecting changes and stability in biodiversity. Examples of factors include but are not limited to:

      • i. Overpopulation;

      • ii. Overexploitation;

      • iii. Habitat destruction;

      • iv. Pollution;

      • v. Introduction of invasive species; and

      • vi. Changes in climate.

    • b. Students describe* the ways the proposed solution decreases the negative effects of human activity on the environment and biodiversity.

  2. Describing criteria and constraints, including quantification when appropriate

    • a. Students describe* and quantify (when appropriate) the criteria (amount of reduction of impacts and human activities to be mitigated) and constraints (for example, cost, human needs, and environmental impacts) for the solution to the problem, along with the tradeoffs in the solution.

  3. Evaluating potential solutions

    • a. Students evaluate the proposed solution for its impact on overall environmental stability and changes.

    • b. Students evaluate the cost, safety, and reliability, as well as social, cultural, and environmental impacts, of the proposed solution for a select human activity that is harmful to an ecosystem.

  4. Refining and/or optimizing the design solution

    • a. Students refine the proposed solution by prioritizing the criteria and making tradeoffs as necessary to further reduce environmental impact and loss of biodiversity while addressing human needs.

HS-LS2-8

Students who demonstrate understanding can:

Evaluate the evidence for the role of group behavior on individual and species’ chances to survive and reproduce.

Clarification Statement: Emphasis is on: (1) distinguishing between group and individual behavior, (2) identifying evidence supporting the outcomes of group behavior, and (3) developing logical and reasonable arguments based on evidence. Examples of group behaviors could include flocking, schooling, herding, and cooperative behaviors such as hunting, migrating, and swarming.

Science and Engineering Practices

Engaging in Argument from Evidence

Engaging in argument from evidence in 9– 12 builds on K–8 experiences and progresses to using appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about the natural and designed world(s). Arguments may also come from current scientific or historical episodes in science.

Connections to Nature of Science

Scientific Knowledge is Open to Revision in Light of New Evidence

Disciplinary Core Ideas

LS2.D: Social Interactions and Group Behavior

Crosscutting Concepts

Cause and Effect

Observable features of the student performance by the end of the course:

  1. Identifying the given explanation and the supporting evidence

    • a. Students identify the given explanation that is supported by the evidence to be evaluated, and which includes the following idea: Group behavior can increase the chances for an individual and

a species to survive and reproduce.

  1. Identifying any potential additional evidence that is relevant to the evaluation

    • a. Students identify additional evidence (in the form of data, information, or other appropriate forms) that was not provided but is relevant to the explanation and to evaluating the given evidence, and which includes evidence for causal relationships between specific group behaviors (e.g., flocking, schooling, herding, cooperative hunting, migrating, swarming) and individual survival and reproduction rates.

  2. Evaluating and critiquing

    • a. Students use their additional evidence to assess the validity, reliability, strengths, and weaknesses of the given evidence along with its ability to support logical and reasonable arguments about the outcomes of group behavior.

    • b. Students evaluate the given evidence for the degree to which it supports a causal claim that group behavior can have a survival advantage for some species, including how the evidence allows for distinguishing between causal and correlational relationships, and how it supports cause and effect relationships between various kinds of group behavior and individual survival rates (for example, the relationship between moving in a group and individual survival rates, compared to the survival rate of individuals of the same species moving alone or outside of the group).

HS-LS3-1

Students who demonstrate understanding can:

Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring.

Assessment Boundary: Assessment does not include the phases of meiosis or the biochemical mechanism of specific steps in the process.

Science and Engineering Practices

Asking Questions and Defining Problems

Asking questions and defining problems in 9-12 builds on K-8 experiences and progresses to formulating, refining and evaluating empirically testable questions and design problems using models and simulations.

Disciplinary Core Ideas

LS1.A: Structure and Function
LS3.A: Inheritance of Traits

Crosscutting Concepts

Cause and Effect

Observable features of the student performance by the end of the course:

  1. Addressing phenomena or scientific theories

    • a. Students use models of DNA to formulate questions, the answers to which would clarify:

      • i. The cause and effect relationships (including distinguishing between causal and correlational relationships) between DNA, the proteins it codes for, and the resulting traits observed in an organism;

      • ii. That the DNA and chromosomes that are used by the cell can be regulated in multiple ways; and

      • iii. The relationship between the non-protein coding sections of DNA and their functions (e.g., regulatory functions) in an organism.

  2. Evaluating empirical testability

    • a. Students’ questions are empirically testable by scientists.

HS-LS3-2

Students who demonstrate understanding can:

Make and defend a claim based on evidence that inheritable genetic variations may result from: (1) new genetic combinations through meiosis, (2) viable errors occurring during replication, and/or (3) mutations caused by environmental factors.

Assessment Boundary: Assessment does not include the phases of meiosis or the biochemical mechanism of specific steps in the process.

Science and Engineering Practices

Engaging in Argument from Evidence

Engaging in argument from evidence in 9-12 builds on K-8 experiences and progresses to using appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about the natural and designed world(s). Arguments may also come from current scientific or historical episodes in science.

Disciplinary Core Ideas

LS3.B: Variation of Traits

Crosscutting Concepts

Cause and Effect

Observable features of the student performance by the end of the course:

  1. Developing a claim

    • a. Students make a claim that includes the idea that inheritable genetic variations may result from:

      • i. New genetic combinations through meiosis;

      • ii. Viable errors occurring during replication; and

      • iii. Mutations caused by environmental factors.

  2. Identifying scientific evidence

    • a. Students identify and describe* evidence that supports the claim, including:

      • i. Variations in genetic material naturally result during meiosis when corresponding sections of chromosome pairs exchange places.

      • ii. Genetic mutations can occur due to: a) errors during replication; and/or b) environmental factors.

      • iii. Genetic material is inheritable.

    • b. Students use scientific knowledge, literature, student-generated data, simulations and/or other sources for evidence.

  3. Evaluating and critiquing evidence

    • a. Students identify the following strengths and weaknesses of the evidence used to support the claim:

      • i. Types and numbers of sources;

      • ii. Sufficiency to make and defend the claim, and to distinguish between causal and correlational relationships; and

      • iii. Validity and reliability of the evidence.

  4. Reasoning and synthesis

    • a. Students use reasoning to describe* links between the evidence and claim, such as:

      • i. Genetic mutations produce genetic variations between cells or organisms.

      • ii. Genetic variations produced by mutation and meiosis can be inherited.

    • b. Students use reasoning and valid evidence to describe* that new combinations of DNA can arise from several sources, including meiosis, errors during replication, and mutations caused by environmental factors.

    • c. Students defend a claim against counter-claims and critique by evaluating counter-claims and by describing* the connections between the relevant and appropriate evidence and the strongest claim.

HS-LS3-3

Students who demonstrate understanding can:

Apply concepts of statistics and probability to explain the variation and distribution of expressed traits in a population.

Clarification Statement: Emphasis is on the use of mathematics to describe the probability of traits as it relates to genetic and environmental factors in the expression of traits.

Assessment Boundary: Assessment does not include Hardy-Weinberg calculations.

Science and Engineering Practices

Analyzing and Interpreting Data

Analyzing data in 9-12 builds on K-8 experiences and progresses to introducing more detailed statistical analysis, the comparison of data sets for consistency, and the use of models to generate and analyze data.

Disciplinary Core Ideas

LS3.B: Variation of Traits

Crosscutting Concepts

Scale, Proportion, and Quantity

Algebraic thinking is used to examine scientific data and predict the effect of a change in one variable on another (e.g., linear growth vs. exponential growth).

Connections to Nature of Science

Science is a Human Endeavor

Observable features of the student performance by the end of the course:

  1. Organizing data

    • a. Students organize the given data by the frequency, distribution, and variation of expressed traits in the population.

  2. Identifying relationships

    • a. Students perform and use appropriate statistical analyses of data, including probability measures, to determine the relationship between a trait’s occurrence within a population and environmental factors.

  3. Interpreting data

    • a. Students analyze and interpret data to explain the distribution of expressed traits, including:

      • i. Recognition and use of patterns in the statistical analysis to predict changes in trait distribution within a population if environmental variables change; and

      • ii. Description* of the expression of a chosen trait and its variations as causative or correlational to some environmental factor based on reliable evidence.

HS-LS4-1

Students who demonstrate understanding can:

Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.

Clarification Statement: Emphasis is on a conceptual understanding of the role each line of evidence has relating to common ancestry and biological evolution. Examples of evidence could include similarities in DNA sequences, anatomical structures, and order of appearance of structures in embryological development.

Science and Engineering Practices

Obtaining, Evaluating, and Communicating Information

Obtaining, evaluating, and communicating information in 9–12 builds on K–8 experiences and progresses to evaluating the validity and reliability of the claims, methods, and designs.

Connections to Nature of Science

Science Models, Laws, Mechanisms, and Theories Explain Natural Phenomena

Disciplinary Core Ideas

LS4.A: Evidence of Common Ancestry and Diversity

Crosscutting Concepts

Patterns

Different patterns may be observed at each of the scales at which a system is studied and can provide evidence for causality in explanations of phenomena.

Connections to Nature of Science

Scientific Knowledge Assumes an Order and Consistency in Natural Systems

Observable features of the student performance by the end of the course:

  1. Communication style and format

    • a. Students use at least two different formats (e.g., oral, graphical, textual and mathematical), to communicate scientific information, including that common ancestry and biological evolution are supported by multiple lines of empirical evidence. Students cite the origin of the information as appropriate.

  2. Connecting the DCIs and the CCCs

    • a. Students identify and communicate evidence for common ancestry and biological evolution, including:

      • i. Information derived from DNA sequences, which vary among species but have many similarities between species;

      • ii. Similarities of the patterns of amino acid sequences, even when DNA sequences are slightly different, including the fact that multiple patterns of DNA sequences can code for the same amino acid;

      • iii. Patterns in the fossil record (e.g., presence, location, and inferences possible in lines of evolutionary descent for multiple specimens); and

      • iv. The pattern of anatomical and embryological similarities.

    • b. Students identify and communicate connections between each line of evidence and the claim of common ancestry and biological evolution.

    • c. Students communicate that together, the patterns observed at multiple spatial and temporal scales (e.g., DNA sequences, embryological development, fossil records) provide evidence for causal relationships relating to biological evolution and common ancestry.

HS-LS4-2

Students who demonstrate understanding can:

Construct an explanation based on evidence that the process of evolution primarily results from four factors: (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

Clarification Statement: Emphasis is on using evidence to explain the influence each of the four factors has on the number of organisms, behaviors, morphology, or physiology in terms of ability to compete for limited resources and subsequent survival of individuals and adaptation of species. Examples of evidence could include mathematical models such as simple distribution graphs and proportional reasoning.

Science and Engineering Practices

Constructing Explanations and Designing Solutions

Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.

Disciplinary Core Ideas

LS4.B: Natural Selection
LS4.C: Adaptation

Crosscutting Concepts

Cause and Effect

Observable features of the student performance by the end of the course:

  1. Articulating the explanation of phenomena

    • a. Students construct an explanation that includes a description* that evolution is caused primarily by one or more of the four factors: (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

  2. Evidence

    • a. Students identify and describe* evidence to construct their explanation, including that:

      • i. As a species grows in number, competition for limited resources can arise.

      • ii. Individuals in a species have genetic variation (through mutations and sexual reproduction) that is passed on to their offspring.

      • iii. Individuals can have specific traits that give them a competitive advantage relative to other individuals in the species.

    • b. Students use a variety of valid and reliable sources for the evidence (e.g., data from investigations, theories, simulations, peer review).

  3. Reasoning

    • a. Students use reasoning to connect the evidence, along with the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future, to construct the explanation. Students describe* the following chain of reasoning for their explanation:

      • i. Genetic variation can lead to variation of expressed traits in individuals in a population.

      • ii. Individuals with traits that give competitive advantages can survive and reproduce at higher rates than individuals without the traits because of the competition for limited resources.

      • iii. Individuals that survive and reproduce at a higher rate will provide their specific genetic variations to a greater proportion of individuals in the next generation.

      • iv. Over many generations, groups of individuals with particular traits that enable them to survive and reproduce in distinct environments using distinct resources can evolve into a different species.

    • b. Students use the evidence to describe* the following in their explanation:

      • i. The difference between natural selection and biological evolution (natural selection is a process, and biological evolution can result from that process); and

      • ii. The cause and effect relationship between genetic variation, the selection of traits that provide comparative advantages, and the evolution of populations that all express the trait.

HS-LS4-3

Students who demonstrate understanding can:

Apply concepts of statistics and probability to support explanations that organisms with an advantageous heritable trait tend to increase in proportion to organisms lacking this trait.

Clarification Statement: Emphasis is on analyzing shifts in numerical distribution of traits and using these shifts as evidence to support explanations.

Science and Engineering Practices

Analyzing and Interpreting Data

Analyzing data in 9–12 builds on K–8 experiences and progresses to introducing more detailed statistical analysis, the comparison of data sets for consistency, and the use of models to generate and analyze data.

Disciplinary Core Ideas

LS4.B: Natural Selection
LS4.C: Adaptation

Crosscutting Concepts

Patterns

Observable features of the student performance by the end of the course:

  1. Organizing data

    • a. Students organize data (e.g., using tables, graphs and charts) by the distribution of genetic traits over time.

    • b. Students describe* what each dataset represents

  2. Identifying relationships

    • a. Students perform and use appropriate statistical analyses of data, including probability measures, to determine patterns of change in numerical distribution of traits over various time and population scales.

  3. Interpreting data

    • a. Students use the data analyses as evidence to support explanations about the following:

      • i. Positive or negative effects on survival and reproduction of individuals as relating to their expression of a variable trait in a population;

      • ii. Natural selection as the cause of increases and decreases in heritable traits over time in

    • a. population, but only if it affects reproductive success; and

      • iii. The changes in distribution of adaptations of anatomical, behavioral, and physiological traits in a population.

HS-LS4-4

Students who demonstrate understanding can:

Construct an explanation based on evidence for how natural selection leads to adaptation of populations.

Clarification Statement: Emphasis is on using data to provide evidence for how specific biotic and abiotic differences in ecosystems (such as ranges of seasonal temperature, long-term climate change, acidity, light, geographic barriers, or evolution of other organisms) contribute to a change in gene frequency over time, leading to adaptation of populations.

Science and Engineering Practices

Constructing Explanations and Designing Solutions

Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories.

Disciplinary Core Ideas

LS4.C: Adaptation

Crosscutting Concepts

Cause and Effect
Connections to Nature of Science

Scientific Knowledge Assumes an Order and Consistency in Natural Systems

Observable features of the student performance by the end of the course:

  1. Articulating the explanation of phenomena

    • a. Students construct an explanation that identifies the cause and effect relationship between natural selection and adaptation.

  2. Evidence

    • a. Students identify and describe* the evidence to construct their explanation, including:

      • i. Changes in a population when some feature of the environment changes;

      • ii. Relative survival rates of organisms with different traits in a specific environment;

      • iii. The fact that individuals in a species have genetic variation (through mutations and sexual reproduction) that is passed on to their offspring; and

      • iv. The fact that individuals can have specific traits that give them a competitive advantage relative to other individuals in the species.

    • b. Students use a variety of valid and reliable sources for the evidence (e.g., theories, simulations, peer review, students’ own investigations)

  3. Reasoning

    • a. Students use reasoning to synthesize the valid and reliable evidence to distinguish between cause and correlation to construct the explanation about how natural selection provides a mechanism for species to adapt to changes in their environment, including the following elements:

      • i. Biotic and abiotic differences in ecosystems contribute to changes in gene frequency over time through natural selection.

      • ii. Increasing gene frequency in a population results in an increasing fraction of the population in each successive generation that carries a particular gene and expresses a particular trait.

      • iii. Over time, this process leads to a population that is adapted to a particular environment by the widespread expression of a trait that confers a competitive advantage in that environment.

HS-LS4-5

Students who demonstrate understanding can:

Evaluate the evidence supporting claims that changes in environmental conditions may result in: (1) increases in the number of individuals of some species, (2) the emergence of new species over time, and (3) the extinction of other species.

Clarification Statement: Emphasis is on determining cause and effect relationships for how changes to the environment such as deforestation, fishing, application of fertilizers, drought, flood, and the rate of change of the environment affect distribution or disappearance of traits in species.

Science and Engineering Practices

Engaging in Argument from Evidence

Engaging in argument from evidence in 9- 12 builds on K-8 experiences and progresses to using appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about the natural and designed world(s). Arguments may also come from current or historical episodes in science.

Disciplinary Core Ideas

LS4.C: Adaptation

Crosscutting Concepts

Cause and Effect

Observable features of the student performance by the end of the course:

  1. Identifying the given claims and evidence to be evaluated

    • a. Students identify the given claims, which include the idea that changes in environmental conditions may result in:

      • i. Increases in the number of individuals of some species;

      • ii. The emergence of new species over time; and

      • iii. The extinction of other species.

    • b. Students identify the given evidence to be evaluated.

  2. Identifying any potential additional evidence that is relevant to the evaluation

    • a. Students identify and describe* additional evidence (in the form of data, information, models, or other appropriate forms) that was not provided but is relevant to the claims and to evaluating the given evidence, including:

      • i. Data indicating the change over time in: a) The number of individuals in each species; b) The number of species in an environment; and c) The environmental conditions.

      • ii. Environmental factors that can determine the ability of individuals in a species to survive and reproduce.

  3. Evaluating and critiquing

    • a. Students use their additional evidence to assess the validity, reliability, strengths, and weaknesses of the given evidence, along with its ability to support logical and reasonable arguments about the outcomes of group behavior.

    • b. Students assess the ability of the given evidence to be used to determine causal or correlational effects between environmental changes, the changes in the number of individuals in each species, the number of species in an environment, and/or the emergence or extinction of species.

  4. Reasoning and synthesis

    • a. Students evaluate the degree to which the given empirical evidence can be used to construct logical arguments that identify causal links between environmental changes and changes in the number of individuals or species based on environmental factors that can determine the ability of individuals in a species to survive and reproduce

HS-LS4-6

Students who demonstrate understanding can:

Create or revise a simulation to test a solution to mitigate adverse impacts of human activity on biodiversity.*

Clarification Statement: Emphasis is on designing solutions for a proposed problem related to threatened or endangered species, or to genetic variation of organisms for multiple species.

Science and Engineering Practices

Using Mathematics and Computational Thinking

Mathematical and computational thinking in 9-12 builds on K-8 experiences and progresses to using algebraic thinking and analysis, a range of linear and nonlinear functions including trigonometric functions, exponentials and logarithms, and computational tools for statistical analysis to analyze, represent, and model data. Simple computational simulations are created and used based on mathematical models of basic assumptions.

Disciplinary Core Ideas

LS4.C: Adaptation
LS4.D: Biodiversity and Humans
ETS1.B: Developing Possible Solutions

Crosscutting Concepts

Cause and Effect

Observable features of the student performance by the end of the course:

  1. Representation

    • a. Students create or revise a simulation that:

      • i. Models effects of human activity (e.g., overpopulation, overexploitation, adverse habitat alterations, pollution, invasive species, changes in climate) on a threatened or endangered species or to the genetic variation within a species; and

      • ii. Provides quantitative information about the effect of the solutions on threatened or endangered species.

    • b. Students describe* the components that are modeled by the computational simulation, including human activity (e.g., overpopulation, overexploitation, adverse habitat alterations, pollution, invasive species, changes in climate) and the factors that affect biodiversity.

    • c. Students describe* the variables that can be changed by the user to evaluate the proposed solutions, tradeoffs, or other decisions.

  2. Computational modeling

    • a. Students use logical and realistic inputs for the simulation that show an understanding of the reliance of ecosystem function and productivity on biodiversity, and that take into account the constraints of cost, safety, and reliability as well as cultural, and environmental impacts.

    • b. Students use the simulation to identify possible negative consequences of solutions that would outweigh their benefits.

  3. Analysis

    • a. Students compare the simulation results to expected results.

    • b. Students analyze the simulation results to determine whether the simulation provides sufficient information to evaluate the solution.

    • c. Students identify the simulation’s limitations.

    • d. Students interpret the simulation results, and predict the effects of the specific design solutions on biodiversity based on the interpretation.

  4. Revision

    • a. Students revise the simulation as needed to provide sufficient information to evaluate the solution.