Clarification Statement - S.MS.LS.1.6.CS:
Emphasis is on tracing movement of matter and flow of energy.

Assessment Boundary - S.MS.LS.1.6.AB:
Assessment does not include the biochemical mechanisms of photosynthesis.

Science and Engineering Practices - 6-8.SEP6.3:
Construct a scientific explanation based on valid and reliable evidence obtained from sources (including the students’ own experiments) and the assumption that theories and laws that describe the natural world operate today as they did in the past and wil

Disciplinary Core Ideas - S.MS.LS.1.6.DCI:
LS1.C: Organization for Matter and Energy Flow in Organisms •Plants, algae (including phytoplankton), and many microorganisms use the energy from light to make sugars (food) from carbon dioxide from the atmosphere and water through the process of photosynthesis, which also releases oxygen. These sugars can be used immediately or stored for growth or later use. PS3.D: Energy in Chemical Processes and Everyday Life •The chemical reaction by which plants produce complex food molecules (sugars) requires an energy input (i.e., from sunlight) to occur. In this reaction, carbon dioxide and water combine to form carbon-based organic molecules and release oxygen.

Crosscutting Concepts - CC5.9:
Within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter.

Clarification Statement - S.MS.LS.1.7.CS:
Emphasis is on describing that molecules are broken apart and put back together and that in this process, energy is released.

Assessment Boundary - S.MS.LS.1.7.AB:
Assessment does not include details of the chemical reactions for respiration or synthesis.

Science and Engineering Practices - 6-8.SEP2.2:
Develop a model to describe unobservable mechanisms.

Disciplinary Core Ideas - S.MS.LS.1.7.DCI:
LS1.C: Organization for Matter and Energy Flow in Organisms •Within individual organisms, food moves through a series of chemical reactions in which it is broken down and rearranged to form new molecules, to support growth, or to release energy. PS3.D: Energy in Chemical Processes and Everyday Life •Cellular respiration in plants and animals involves chemical reactions with oxygen that release stored energy. In these processes, complex molecules containing carbon react with oxygen to produce carbon dioxide and other materials. (secondary to MS-LS1-7)

Crosscutting Concepts - CC5.6:
Matter is conserved because atoms are conserved in physical and chemical processes.

Clarification Statement - S.MS.LS.2.1.CS:
Emphasis is on cause and effect relationships between resources and growth of individual organisms and the numbers of organisms in ecosystems during periods of abundant and scarce resources.

Science and Engineering Practices - 6-8.SEP4.3:
Analyze and interpret data to provide evidence for phenomena.

Disciplinary Core Ideas - S.MS.LS.2.1.DCI:
LS2.A: Interdependent Relationships in Ecosystems •Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. •In any ecosystem, organisms and populations with similar requirements for food, water, oxygen, or other resources may compete with each other for limited resources, access to which consequently constrains their growth and reproduction. •Growth of organisms and population increases are limited by access to resources.

Crosscutting Concepts - CC2.10:
Cause and effect relationships can be suggested and predicted for complex natural and human designed systems by examining what is known about smaller scale mechanisms within the system.

Clarification Statement - S.MS.LS.2.3.CS:
Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system.

Assessment Boundary - S.MS.LS.2.3.AB:
Assessment does not include the use of chemical reactions to describe the processes.

Science and Engineering Practices - 6-8.SEP2.3:
Develop and use a model to describe phenomena.

Disciplinary Core Ideas - S.MS.LS.2.3.DCI:
LS2.B: Cycle of Matter and Energy Transfer in Ecosystems •Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.

Crosscutting Concepts - CC5.7:
The transfer of energy can be tracked as energy flows through a designed or natural system.

Clarification Statement - S.MS.LS.2.4.CS:
Emphasis is on recognizing patterns in data and making warranted inferences about shifts in populations due to changes in the ecosystems.

Science and Engineering Practices - 6-8.SEP7.1:
Construct and present oral and written arguments supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon or a solution to a problem.

Disciplinary Core Ideas - S.MS.LS.2.4.DCI:
LS2.C: Ecosystem Dynamics, Functioning, and Resilience •Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations.

Crosscutting Concepts - CC6.4:
Small changes in one part of a system might cause large changes in another part.