Ecosystems: Interactions, Energy, and Dynamics
The performance expectations in LS2: Ecosystems: Interactions, Energy, and Dynamics help students formulate an answer to the questions, “How and why do organisms interact with their environment, and what are the effects of these interactions?” The LS2 Disciplinary Core Idea includes four sub-ideas: Interdependent Relationships in Ecosystems, Cycles of Matter and Energy Transfer in Ecosystems, Ecosystem Dynamics, Functioning, and Resilience, and Social Interactions and Group Behavior High school students can use mathematical reasoning to demonstrate understanding of fundamental concepts of carrying capacity, factors affecting biodiversity and populations, and the cycling of matter and flow of energy among organisms in an ecosystem. These mathematical models provide support for students’ conceptual understanding of systems and their ability to develop design solutions for reducing the impact of human activities on the environment and maintaining biodiversity. The crosscutting concepts of systems and system models play a central role in students’ understanding of science and engineering practices and core ideas of ecosystems (NGSS Lead States 2013d).
California Department of Education. 2018. 2016 California Science Framework Chapter 8. Sacramento, CA: California Department of Education, 1044.
Big Idea Success Criteria
The categories and their related standards below unpack the success criteria of this big idea.
Guiding Questions
- How and why do populations change over time?
- How do populations change when their resources become scarce?
Primary Standards
- HS-LS2-1. Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales. [Clarification Statement: Emphasis is on quantitative analysis and comparison of the relationships among interdependent factors including boundaries, resources, climate, and competition Examples of mathematical comparisons could include graphs, charts, histograms, and population changes gathered from simulations or historical data sets ] [Assessment Boundary: Assessment does not include deriving mathematical equations to make comparisons]
- HS-LS2-2. 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 ]
Guiding Questions
- Why is the cycling of matter and energy important?
- How are matter and energy linked in ecosystems?
Primary Standards
- HS-LS2-3. 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.]
- HS-LS2-4. 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.]
- HS-LS2-5. 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.]
Guiding Questions
- What types of interactions cause changes in ecosystems that ultimately affect populations?
- To what extent can humans “undo” their negative impact on the environment?
Primary Standards
- HS-LS2-6. 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. [Clarification Statement: Examples of changes in ecosystem conditions could include modest biological or physical changes, such as moderate
hunting or a seasonal flood; and extreme changes, such as volcanic eruption or sea level rise.]
- HS-LS2-7. 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.]
*The performance expectations marked with an asterisk integrate traditional science content with engineering through a practice or disciplinary core idea.
Guiding Questions
- How do populations ensure that their gene pool gets passed on?
- What affects a population’s chance of survival?
Primary Standards
- HS-LS2-8. 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.]
California Department of Education. 2018. 2016 California Science Framework Chapter 8. Sacramento, CA: California Department of Education, 1070.
Alternative Means of Expression
This big idea does not have created or curated examples of alternative means of expression due to the project scope and timeline. If you have example options you would like to share with the initiative team, please use the BYOT option.
Sample Coursework
Bring Your Own Task (BYOT)
A Call to IEP Teams
We want students’ IEP team members to share their ideas regarding viable alternative means of expression pertaining to this big idea for students with disabilities, including those eligible for the CAA, these teams serve. IEP teams can define viable alternative means of expression for an individual student with an IEP, as long as these mediums meet the local requirements of the coursework.
A Call to Content-based Educators
In addition to IEP teams, we know secondary teachers and district curriculum leads have a wealth of experience and ideas related to innovative ways to assess students’ understanding of this content. We are interested in sample alternative means of expression this community sees as viable assessments of this big idea.
Please use the entry boxes below to share these ideas.
Important Note —These assessment tools will not be shared outside the review of the initiative team and will remain the intellectual property of the users who have made this submission. Furthermore, feedback or comments from the initiative team will not be given to uploaded content, nor does uploading materials imply that the alternative means of expression strategy is a viable option for this big idea.
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