Unit 1 Summary:  Structure and Properties of Matter

How is it that everything is made of star dust?

Students build understandings of what occurs at the atomic and molecular scale. Students apply their understanding that pure substances have characteristic properties and are made from a single type of atom or molecule. They also provide a molecular level accounts to explain states of matter and changes between states. The crosscutting concepts of cause and effect, scale, proportion and quantity, structure and function, interdependence of science, engineering, and technology,  and the influence of science, engineering and technology on society and the natural world provide a framework for understanding the disciplinary core ideas. Students demonstrate grade appropriate proficiency in developing and using models, and obtaining, evaluating, and communicating information. Students are also expected to use the scientific and engineering practices to demonstrate understanding of the core ideas.

Student Learning Objectives

Develop models to describe the atomic composition of simple molecules and extended structures. [Clarification Statement: Emphasis is on developing models of molecules that vary in complexity. Examples of simple molecules could include ammonia and methanol. Examples of extended structures could include sodium chloride or diamonds. Examples of molecular-level models could include drawings, 3D ball and stick structures, or computer representations showing different molecules with different types of atoms. The substructure of atoms and the periodic table are learned in high school chemistry.] [Assessment Boundary: Assessment does not include valence electrons and bonding energy, discussing the ionic nature of subunits of complex structures, or a complete depiction of all individual atoms in a complex molecule or extended structure.]  (MS-PS1-1)  (CRP2) (CRP6)

Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred. [Clarification Statement: Examples of reactions could include burning sugar or steel wool, fat reacting with sodium hydroxide, and mixing zinc with hydrogen chloride.] [Assessment Boundary: Assessment is limited to analysis of the following properties: density, melting point, boiling point, solubility, flammability, and odor.] (MS-PS1-2) (CRP8) (CRP11)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 3 

Connecting with ELA/Literacy and Math p. 3

Modifications p. 4

Research on Learning p. 5

Prior Learning p. 5 

Connections to Other Units p. 6

Sample Open Education Resources p. 7

Appendix A: NGSS and Foundations p. 8


                                       Unit Sequence

Part A: If the universe is not made of Legos®, then what is it made of?

Concepts

Formative Assessment

  • Substances are made from different types of atoms.
  • Atoms are the basic units of matter.
  • Substances combine with one another in various ways.
  • Molecules are two or more atoms joined together.
  • Atoms form molecules that range in size from two to thousands of atoms.
  • Molecules can be simple or very complex.
  • Solids may be formed from molecules, or they may be extended structures with repeating subunits (e.g., crystals).

Students who understand the concepts are able to:

  • Develop a model of a simple molecule.
  • Use the model of the simple molecule to describe its atomic composition.
  • Develop a model of an extended structure.
  • Use the model of the extended structure to describe its repeating subunits.

[Boundary: The substructure of atoms and the periodic table are learned in high school chemistry.]

                                       Unit Sequence

Part B: Is it possible to tell if two substances mixed or if they reacted with each other?

Concepts

Formative Assessment

  • Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it.
  • Substances react chemically in characteristic ways.
  • In a chemical process, the atoms that make up the original substances are regrouped into different molecules; these new substances have different properties from those of the reactants.
  • The analysis of data on the properties of products and reactants can be used to determine whether a chemical process has occurred.
  • Density, melting point, boiling point, solubility, flammability, and odor are characteristic properties that can be used to identify a pure substance.
  • Macroscopic patterns are related to the nature of the atomic-level structure of a substance.

Students who understand the concepts are able to:

  • Analyze and interpret data to determine similarities and differences from results of chemical reactions between substances before and after they undergo a chemical process.
  • Analyze and interpret data on the properties of substances before and after they undergo a chemical process.
  • Identify and describe possible correlation and causation relationships evidenced in chemical reactions.
  • Make logical and conceptual connections between evidence that chemical reactions have occurred and explanations of the properties of substances before and after they undergo a chemical process.

What It Looks Like in the Classroom

Within this unit, students will use informational text and models (which can include student-generated drawings, 3-D ball-and-stick structures, or computer representations) to understand that matter is composed of atoms and molecules. These models should reflect that substances are made from different types of atoms. Student models can be manipulated to show that molecules can be disassembled into their various atoms and reassembled into new substances according to chemical reactions. This scientific knowledge can be used to explain the properties of substances. Students will examine and differentiate between physical and chemical properties of matter. They are limited to the analysis of the following characteristic properties: density, melting point, boiling point, solubility, flammability, and odor. This analysis of properties serves as evidence to support that chemical reactions of substances cause a rearrangement of atoms to form different molecules.

Students will also recognize that they are using models to observe phenomena too small to be seen. Students who demonstrate this understanding can develop or modify a model of simple molecules to describe the molecules’ atomic composition. Examples of molecules that can be modeled include water, oxygen, carbon dioxide, ammonia, and methanol. Additionally, students will develop and modify a model that describes the atomic composition of an extended structure showing a pattern of repeating subunits. Examples may include sodium chloride and diamonds. Due to the repeating subunit patterns, models can include student-generated drawings, 3-D ball-and-stick structures, and computer representations.

Building upon these experiences, students will analyze and interpret data on the properties of substances in order to provide evidence that a chemical reaction has occurred. They will also analyze and interpret data to determine similarities and differences in findings. Students will recognize that macroscopic patterns are related to the nature of microscopic and atomic-level structure. They will use patterns to identify cause-and-effect relationships and graphs and charts to identify patterns in data.

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts/Literacy

  • Cite specific textual evidence to support analysis of science and technical texts on the characteristic properties of pure substances. Attend to precise details of explanations or descriptions about the properties of substances before and after they undergo a chemical process.
  • Integrate qualitative information (flowcharts, diagrams, models, graphs, or tables) about the characteristic properties of substances before and after a chemical process has occurred with a version of that information expressed visually, or integrate technical information about the characteristic properties of substances before and after a chemical process has occurred with a version of that information expressed visually.

Mathematics

  • Integrate quantitative or technical information about the composition of simple molecules and extended structures that is expressed in words in a text with a version of that information expressed in a model.
  • Reason quantitatively (with amounts, numbers, sizes) and abstractly (with variables).
  • Develop a mathematical model to describe the atomic composition of simple molecules and extended structures.
  • Use ratio and rate reasoning to describe the atomic composition of simple molecules and extended structures.
  • Reason quantitatively with amounts, numbers, and sizes for properties like density, melting point, boiling point, solubility, flammability, and odor, and reason abstractly by assigning labels or symbols.
  • Use ratio and rate reasoning to determine whether a chemical reaction has occurred.
  • Display numerical data for properties such as density, melting point, solubility, flammability, and order in plots on a number line, including dot plots, histograms, and box plots.
  • Summarize numerical data sets on the properties of substances before and after the substances interact to determine whether a chemical reaction has occurred. The summary of the numerical data sets must be in relation to their context.

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.


Research on Student Learning

Middle school students may think everything that exists is matter, including heat, light, and electricity. Alternatively, they may believe that matter does not include liquids and gases or that they are weightless materials.  With specially designed instruction, some middle school students can learn the scientific notion of matter. 

Middle-school and high-school students are deeply committed to a theory of continuous matter. Although some students may think that substances can be divided up into small particles, they do not recognize the particles as building blocks, but as formed as basically continuous substances under certain conditions. 

Students at the beginning of middle school may be at different points in their conceptualization of a "theory" of matter.  Although some 5th  graders may start seeing weight as a fundamental property of all matter, many students in 6th and 7th grade still appear to think of weight simply as "felt weight" -- something whose weight they can't feel is considered to have no weight at all. Accordingly, some students believe that if one keeps dividing a piece of Styrofoam, one would soon obtain a piece that weighed nothing. 

Students of all ages show a wide range of beliefs about the nature and behavior of particles. They lack an appreciation of the very small size of particles; attribute macroscopic properties to particles; believe there must be something in the space between particles; have difficulty in appreciating the intrinsic motion of particles in solids, liquids and gases; and have problems in conceptualizing forces between particles. Despite these difficulties, there is some evidence that carefully designed instruction carried out over a long period of time may help middle-school students develop correct ideas about particles (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

  • Matter of any type can be subdivided into particles that are too small to see, but even then the matter still exists and can be detected by other means.
  • A model showing that gases are made from matter particles that are too small to see and are moving freely around in space can explain many observations, including the inflation and shape of a balloon and the effects of air on larger particles or objects.
  • The amount (weight) of matter is conserved when it changes form, even in transitions in which it seems to vanish.
  • Measurements of a variety of observable properties can be used to identify materials. [Boundary: In the fifth grade, no attempt was made to define the unseen particles or explain the atomic-scale mechanism of evaporation and condensation.]
  • When two or more different substances are mixed, a new substance with different properties may be formed.
  • No matter what reaction or change in properties occurs, the total mass of the substances does not change. [Boundary: Mass and weight were distinguished in 5th grade.]

Future Learning

Chemistry

  • Each atom has a charged substructure consisting of a nucleus, which is made of protons and neutrons surrounded by electrons.
  • The periodic table orders elements horizontally according to the number of protons in the atom’s nucleus; it organizes elements with similar chemical properties vertically, in columns. The repeating patterns of this table reflect patterns of outer electron states.
  • The structure and interactions of matter at the bulk scale are determined by electrical forces within and between atoms.
  • A stable molecule has less energy than the same set of atoms separated; at least this much energy must be provided in order to take the molecule apart.

Earth and space science

  • The star called the sun is changing and will burn out over a lifespan of approximately 10 billion years.
  • The study of stars’ light spectra and brightness is used to identify compositional elements of stars, their movements, and their distances from Earth.
  • The Big Bang theory is supported by observations of distant galaxies receding from our own, by the measured composition of stars and nonstellar gases, and by the maps of spectra of the primordial radiation (cosmic microwave background) that still fills the universe.
  • Other than the hydrogen and helium formed at the time of the Big Bang, nuclear fusion within stars produces all atomic nuclei lighter than and including iron, and the process releases electromagnetic energy. Heavier elements are produced when certain massive stars achieve a supernova stage and explode.
  • Chemical processes, their rates, and whether or not they store or release energy can be understood in terms of collisions of molecules and rearrangements of atoms into new molecules, with consequent changes in the sum of all bond energies in the set of molecules that are matched by changes in kinetic energy.
  • In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present.
  • The fact that atoms are conserved, together with knowledge of the chemical properties of the elements involved, can be used to describe and predict chemical reactions.

Connections to Other Units

Unit 2: Interactions of Matter 

Unit 3: Chemical Reactions


Appendix A: NGSS and Foundations for the Unit

Develop models to describe the atomic composition of simple molecules and extended structures. [Clarification Statement: Emphasis is on developing models of molecules that vary in complexity. Examples of simple molecules could include ammonia and methanol. Examples of extended structures could include sodium chloride or diamonds. Examples of molecular-level models could include drawings, 3D ball and stick structures, or computer representations showing different molecules with different types of atoms. The substructure of atoms and the periodic table are learned in high school chemistry.] [Assessment Boundary: Assessment does not include valence electrons and bonding energy, discussing the ionic nature of subunits of complex structures, or a complete depiction of all individual atoms in a complex molecule or extended structure.]  (MS-PS1-1)

Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred. [Clarification Statement: Examples of reactions could include burning sugar or steel wool, fat reacting with sodium hydroxide, and mixing zinc with hydrogen chloride.] [Assessment Boundary: Assessment is limited to analysis of the following properties: density, melting point, boiling point, solubility, flammability, and odor.] (MS-PS1-2)

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Developing and Using Models

Analyzing and Interpreting Data

PS1.A: Structure and Properties of Matter

PS1.B: Chemical Reactions

Scale, Proportion, and Quantity

Patterns

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

         Connections to Nature of Science

 Scientific Knowledge is Based on Empirical Evidence

  • Science knowledge is based upon logical and conceptual connections between evidence and explanations. (MS-PS1-2)

English Language Arts

Mathematics

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content.

Career Readiness Practices

CRP2. Apply appropriate academic and technical skills.

CRP6. Demonstrate creativity and innovation.

CRP8. Utilize critical thinking to make sense of problems.

CRP11. Use technology to enhance productivity.


Unit 2 Summary:  Interactions of Matter

Students build understandings of what occurs at the atomic and molecular scale. Students apply their understanding that pure substances have characteristic properties and are made from a single type of atom or molecule. They also provide a molecular level accounts to explain states of matter and changes between states. The crosscutting concepts of cause and effect, scale, proportion and quantity, structure and function, interdependence of science, engineering, and technology,  and the influence of science, engineering and technology on society and the natural world provide a framework for understanding the disciplinary core ideas. Students demonstrate grade appropriate proficiency in developing and using models, and obtaining, evaluating, and communicating information. Students are also expected to use the scientific and engineering practices to demonstrate understanding of the core ideas.

Student Learning Objectives

Gather and make sense of information to describe that synthetic materials come from natural resources and impact society. [Clarification Statement: Emphasis is on natural resources that undergo a chemical process to form the synthetic material. Examples of new materials could include new medicine, foods, and alternative fuels.] [Assessment Boundary: Assessment is limited to qualitative information.] (MS-PS1-3) (CRP5) (CRP7) (CRP8) (CRP11)

Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed. [Clarification Statement: Emphasis is on qualitative molecular-level models of solids, liquids, and gases to show that adding or removing thermal energy increases or decreases kinetic energy of the particles until a change of state occurs. Examples of models could include drawings and diagrams. Examples of particles could include molecules or inert atoms. Examples of pure substances could include water, carbon dioxide, and helium.] (MS-PS1-4)  (CRP6) (CRP11)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 4 

Connecting with ELA/Literacy and Math p. 4

Modifications p. 5

Research on Learning p. 6

Prior Learning p. 5 

Connections to Other Units p. 8

Sample Open Education Resources p. 9

Appendix A: NGSS and Foundations p. 9


                                       Unit Sequence

Part A: How can you tell what the molecules are doing in a substance?

Concepts

Formative Assessment

  • Changes in particle motion, temperature, and state of a pure substance occur when thermal energy is added or removed.
  • Qualitative molecular-level models of solids, liquids, and gases can be used to show that adding or removing thermal energy increases or decreases the kinetic energy of the particles until a change of state occurs.
  • Gases and liquids are made of molecules or inert atoms that are moving about relative to each other.
  • In a liquid, the molecules are constantly in contact with others.
  • In a gas, the molecules are widely spaced except when they happen to collide.
  • In a solid, atoms are closely spaced and may vibrate in position but do not change relative locations.
  • The changes of state that occur with variations in temperature or pressure can be described and predicted using models of matter.
  • The term heat as used in everyday language refers both to thermal energy and the transfer of that thermal energy from one object to another.
  • Thermal energy is the motion of atoms or molecules within a substance.
  • In science, heat is used to refer to the energy transferred due to the temperature difference between two objects.
  • The temperature of a system is proportional to the average internal kinetic energy and potential energy per atom or molecule (whichever is the appropriate building block for the system’s material).
  • The details of the relationship between the average internal kinetic energy and the potential energy per atom or molecule depend on the type of atom or molecule and the interactions among the atoms in the material.
  • Temperature is not a direct measure of a system’s total thermal energy.
  • The total thermal energy (sometimes called the total internal energy) of a system depends jointly on the temperature, the total number of atoms in the system, and the state of the material.
  • Cause-and-effect relationships may be used to predict and describe changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed in natural systems.

Students who understand the concepts are able to:

  • Develop a model that predicts and describes changes in particle motion that could include molecules or inert atoms or pure substances.
  • Use cause-and-effect relationships to predict changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed in natural or designed systems.                        

                                       Unit Sequence

Part B: How can we trace synthetic materials back to natural ingredients?

Concepts

Formative Assessment

  • Each pure substance has characteristic physical and chemical properties that can be used to identify it.
  • Substances react chemically in characteristic ways.
  • In a chemical process, the atoms that make up the original substances are regrouped into different molecules.
  • New substances that result from chemical processes have different properties from those of the reactants.
  • Natural resources can undergo a chemical process to form synthetic material.
  • Structures can be designed to serve particular functions by taking into account properties of different materials and how materials can be shaped and used.
  • Engineering advances have led to discoveries of important synthetic materials, and scientific discoveries have led to the development of entire industries and engineered systems using these materials.
  • Technology use varies from region to region and over time.
  • The uses of technologies (engineered/synthetic materials) and any limitations on their use are driven by individual or societal needs, desires, and values.
  • The uses of technologies (engineered/synthetic materials) and any limitations on their use are driven by the findings of scientific research and by differences in such factors as climate, natural resources, and economic conditions.

Students who understand the concepts are able to:

  • Obtain, evaluate, and communicate information to show that synthetic materials come from natural resources and affect society.
  • Gather, read, and synthesize information about how synthetic materials formed from natural resources affect society.
  • Assess the credibility, accuracy, and possible bias of each publication and methods used within the publication.
  • Describe how information about how synthetic materials formed from natural resources affect society is supported or not supported by evidence.

What It Looks Like in the Classroom

Students will locate information that describes changes in particle motion, changes in temperature, or changes in state as thermal energy is added to or removed from a pure substance. Students will then use models to predict and describe the changes in particle motion, temperature, and state of a pure substance. An example could include the change of state of water from its solid (ice) to liquid and vapor with the addition of thermal energy. Students will come to understand that this process is reversible through the removal of thermal energy, where the pure substance can return from a vapor to a liquid and back to a solid state.

Students who accurately demonstrate understanding will be able to develop qualitative molecular-level models of solids, liquids, and gases to show the cause-and-effect relationships of adding or removing thermal energy, which increases or decreases the kinetic energy of the particles until a change of state occurs. Models could include drawings and diagrams.

Students will also need to use mathematics to demonstrate their understanding of the particle motion that is taking place during these changes in state. They will use positive and negative numbers to represent the changes in particle motion and temperature as thermal energy is added or removed. They will then integrate an expression of that same quantitative information in a visual format.

It is important to note that students will need to be responsible for developing the models that they use. It is possible that the teacher could model the process with one type of model and provide opportunities for students to use different types of model to illustrate the same process. After students have a firm understanding of the motion of particles during a phase change, they will be able to move to the next section of this unit. In this portion of the unit of study, students will apply their understanding of particle and chemical change from Unit 1 to make sense of how natural resources react chemically to produce new substances. Students will explain that as a result of the rearrangement of atoms during a chemical process, the synthetic substance has different characteristic properties than the original pure substance. For example, pure substances like methane, carbon monoxide, and carbon dioxide can be combined chemically to form synthetic fuel. The synthetic fuel would have different characteristic properties than the original pure substances.

Within this unit, students will gather, read, and synthesize qualitative information from multiple sources about the use of natural resources to form synthetic materials and how these new materials affect society. Examples of new materials could include new medicine, foods, and alternative fuels. Some sources could include journals, articles, brochures, or digital media from government publications and/or private industries. Students will cite some of these sources to support the analysis of evidence that these synthetic materials were formed from natural resources and have an impact on society. They will pay special attention to the precise details of explanations or descriptions of how these new substances affect society. Students will also include relevant information from multiple print and digital sources about these impacts. While gathering this information, they will use search terms effectively, assess the credibility and accuracy of each source, and quote or paraphrase the data and conclusions of others while avoiding plagiarism and following a standard format for citation.

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts/Literacy

  • Cite specific text to support the analysis of evidence that synthetic materials formed from natural resources affect society. Attend to the precise details of explanations or descriptions.
  • Gather relevant information from multiple print and digital sources about the impact on society of synthetic materials that are formed from natural resources. Use search terms effectively, assess the credibility and accuracy of each source, and quote or paraphrase the data and conclusions of others while avoiding plagiarism and following a standard format for citation.

Mathematics

  • Integrate quantitative information about changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed that is expressed in words with a version of that information that is expressed visually.
  • Understand that positive and negative numbers are used together to describe quantities having opposite directions or values. Use positive and negative numbers to represent changes in particle motion and temperature when thermal energy s added or removed, explaining the meaning of zero in each situation.

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.


Research on Student Learning

Students may think everything that exists is matter, including heat, light, and electricity.  Alternatively, they may believe that matter does not include liquids and gases or they are weightless materials. With specially designed instruction, some middle school students can learn the scientific notion of matter.

Students are deeply committed to a theory of continuous matter.  Although some students may think that substances can be divided up into small particles, they do not recognize the particles as building blocks, but as formed as basically continuous substances under certain conditions.

Students at beginning of middle school may be at different points in their conceptualization of a "theory" of matter. Although some 5th graders may start seeing weight as a fundamental property of all matter, many students in 6th and 7th grade still appear to think of weight simply as "felt weight" -- something whose weight they can't feel is considered to have no weight at all. Accordingly, some students believe that if one keeps dividing a piece of Styrofoam, one would soon obtain a piece that weighed nothing.

Students of all ages show a wide range of beliefs about the nature and behavior of particles. They lack an appreciation of the very small size of particles; attribute macroscopic properties to particles; believe there must be something in the space between particles; have difficulty in appreciating the intrinsic motion of particles in solids, liquids and gases; and have problems in conceptualizing forces between particles.  Despite these difficulties, there is some evidence that carefully designed instruction carried out over a long period of time may help middle-school students develop correct ideas about particles. (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

Future Learning

Chemistry

  • Each atom has a charged substructure consisting of a nucleus made of protons and neutrons surrounded by electrons.
  • The periodic table orders elements horizontally by the number of protons in nucleus of the element’s atoms and arranges elements with similar chemical properties vertically in columns. The repeating patterns of this table reflect patterns of outer electron states.
  • Electrical forces within and between atoms determine the structure and interactions of matter at the bulk scale.
  • A stable molecule has less energy than the same set of atoms separated; at least this energy must be provided in order to take the molecule apart.
  • Chemical processes, their rates, and whether or not they store ore release energy can be understood in terms of the collisions of molecules and the rearrangements of atoms into new molecules, with in kinetic energy.
  • In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present.
  • The fact that atoms are conserved, together with knowledge of the chemical properties of the elements involved, can be used to describe and predict chemical reactions.

Physics

  • Energy is a quantitative property of a system that depends on the motion and interactions of matter and radiation within that system. That there is a single quantity called energy is due to the fact that a system’s total energy is conserved even as, within the system, energy is continually transferred from one object to another and between its various possible forms.
  • At the macroscopic scale, energy manifests itself in multiple ways, such as in motion, sound, light, and thermal energy. These relationships are better understood at the microscopic scale, at which all of the different manifestations of energy can be modeled as a combination of energy associated with the motion of particles and energy associated with the configuration (relative position) of the particles.
  • In some cases the relative position of energy can be thought of as stored in fields (which mediate interactions between particles). This last concept includes radiation, a phenomenon in which energy stored in fields moves across space.

Life science

  • Ecosystems have carrying capacities, which are limits to the numbers of organisms and populations they can support. These limits result from such factors as the availability of living and nonliving resources and from such challenges such as predation, competition, and disease. Organisms would have the capacity to produce populations of great size were it not for the fact that environments and resources are finite. This fundamental tension affects the abundance (number of individuals) of species in any given ecosystem.
  • Biodiversity is increased by the formation of new species (speciation) and decreased by the loss of species (extinction).
  • Humans depend on the living world for resources and other benefits provided by biodiversity. But human activity is also having adverse impacts on biodiversity through overpopulation, overexploitation, habitat destruction, pollution, introduction of invasive species, and climate change. Thus sustaining biodiversity so that ecosystem functioning and productivity are maintained is essential to supporting and enhancing life on Earth. Sustaining biodiversity also aids humanity by preserving landscapes of recreational or inspirational value.
  • Resource availability has guided the development of human society.
  • All forms of energy production and other resource extraction have associated economic, social, environmental, and geopolitical costs and risks as well as benefits. New technologies and social regulations can change the balance of these factors.

Connections to Other Units

Grade 7 Unit 1: Properties of Matter

  • Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.
  • Solids may be formed from molecules, or they may be extended structures with repeating subunits (e.g., crystals).
  • Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it.
  • Substances react chemically in characteristic ways. In a chemical process, the atoms that make up the original substances are regrouped into different molecules, and these new substances have different properties from those of the reactants.

Grade 7 Unit 3: Chemical Reactions


Appendix A: NGSS and Foundations for the Unit

Gather and make sense of information to describe that synthetic materials come from natural resources and impact society. [Clarification Statement: Emphasis is on natural resources that undergo a chemical process to form the synthetic material. Examples of new materials could include new medicine, foods, and alternative fuels.] [Assessment Boundary: Assessment is limited to qualitative information.] (MS-PS1-3)

Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed. [Clarification Statement: Emphasis is on qualitative molecular-level models of solids, liquids, and gases to show that adding or removing thermal energy increases or decreases kinetic energy of the particles until a change of state occurs. Examples of models could include drawings and diagrams. Examples of particles could include molecules or inert atoms. Examples of pure substances could include water, carbon dioxide, and helium.] (MS-PS1-4)

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Obtaining, Evaluating, and Communicating Information

Developing and Using Models

PS1.A: Structure and Properties of Matter

PS1.B: Chemical Reactions

PS3.A: Definitions of Energy

Structure and Function

Cause and Effect

   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

        Connections to Engineering, Technology,

                     and Applications of Science

 Interdependence of Science, Engineering, and Technology

  • Engineering advances have led to important discoveries in virtually every field of science, and scientific discoveries have led to the development of entire industries and engineered systems. (MS-PS1-3)

Influence of Science, Engineering and Technology on Society and the Natural World

English Language Arts

Mathematics

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content.

Career Readiness Practices

.

CRP5. Consider the environmental, social and economic impacts of decisions.

CRP6. Demonstrate creativity and innovation.

CRP7. Employ valid and reliable research strategies.

CRP8. Utilize critical thinking to make sense of problems.

CRP11. Use technology to enhance productivity.

Unit 3 Summary:  Chemical Reactions

How do substances combine or change (react) to make new substances?

Students provide molecular-level accounts of states of matters and changes between states, of how chemical reactions involve regrouping of atoms to form new substances, and of how atoms rearrange during chemical reactions. Students also apply their understanding of optimization design and process in engineering to chemical reaction systems. The crosscutting concept of energy and matter provides a framework for understanding the disciplinary core ideas. Students are expected to demonstrate proficiency in developing and using models, analyzing and interpreting data, designing solutions, and obtaining, evaluating, and communicating information. Students are also expected to use these science and engineering practices to demonstrate understanding of the disciplinary core ideas.

Student Learning Objectives

Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved. [Clarification Statement: Emphasis is on law of conservation of matter and on physical models or drawings, including digital forms, that represent atoms.] [Assessment Boundary: Assessment does not include the use of atomic masses, balancing symbolic equations, or intermolecular forces.] (MS-PS1-5) (CRP2) (CRP6) (CRP7)

Undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes.* [Clarification Statement: Emphasis is on the design, controlling the transfer of energy to the environment, and modification of a device using factors such as type and concentration of a substance. Examples of designs could involve chemical reactions such as dissolving ammonium chloride or calcium chloride.] [Assessment Boundary: Assessment is limited to the criteria of amount, time, and temperature of substance in testing the device.] (MS-PS1-6) (CRP2) (CRP4) (CRP6) (CRP7) (CRP8)

Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success. (MS-ETS1-3) (CRP8) (CRP11)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 3 

Connecting with ELA/Literacy and Math p. 4

Modifications p. 5

Research on Learning p. 6

Prior Learning p. 6 

Connections to Other Units p. 7

Sample Open Education Resources p. 8

Appendix A: NGSS and Foundations p. 9


                                       Unit Sequence

Part A: What happens to the atoms when I bake a cake?

Concepts

Formative Assessment

  • Substances react chemically in characteristic ways.
  • In a chemical process, the atoms that make up the original substances are regrouped into different molecules.
  • New substances created in a chemical process have different properties from those of the reactants.
  • The total number of each type of atom in a chemical process is conserved, and thus the mass does not change (the law of conservation of matter).
  • Matter is conserved because atoms are conserved in physical and chemical processes.
  • The law of conservation of mass is a mathematical description of natural phenomena.

Students who understand the concepts are able to:

  • Use physical models or drawings, including digital forms, to represent atoms in a chemical process.
  • Use mathematical descriptions to show that the number of atoms before and after a chemical process is the same.                

                                       Unit Sequence

Part B: How can a device be designed, constructed, tested, and modified that either releases or absorbs thermal energy by chemical processes?

Concepts

Formative Assessment

  • Some chemical reactions release energy, while others store energy.
  • The transfer of thermal energy can be tracked as energy flows through a designed or natural system.
  • Models of all kinds are important for testing solutions.
  • There are systematic processes for evaluating solutions with respect to how well they meet the criteria and constraints of a problem.
  • The iterative process of testing the most promising solutions and modifying what is proposed on the basis of the test results leads to greater refinement and ultimately to an optimal solution.
  • A solution needs to be tested and then modified on the basis of the test results in order to for it to be improved.
  • Although one design may not perform the best across all tests, identifying the characteristics of the design that performed the best in each test can provide useful information for the redesign process.
  • Some of the characteristics identified as having the best performance may be incorporated into the new design.

Students who understand the concepts are able to:

  • Undertake a design project, engaging in the design cycle, to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes.
  • Specific criteria are limited to amount, time, and temperature of a substance.
  • Analyze and interpret data for the amount, time, and temperature of a substance in testing a device that either releases or absorbs thermal energy by chemical processes to determine similarities and differences in findings.
  • Develop a model to generate data for testing a device that either releases or absorbs thermal energy by chemical processes, including those representing inputs and outputs of thermal energy.
  • Track the transfer of thermal energy as energy flows through a designed system that either releases or absorbs thermal energy by chemical processes.

What It Looks Like in the Classroom

Students begin by gaining understanding that substances react chemically in very characteristic ways. To develop this understanding, students will follow precisely a multistep procedure when carrying out experiments that involve chemical reactions that release energy and chemical reactions that absorb energy. As part of their data analysis, students will integrate quantitative information about atoms before and after the chemical reaction. The analysis will include translating written information into information that is expressed in a physical model or drawing or in digital forms. Reasoning both quantitatively and abstractly to communicate their understanding of these reactions, students will model the law of conservation of matter.

They will use ratio and rate to demonstrate that the total number of atoms involved in the chemical reactions does not change and therefore mass is conserved. Within this unit, students will develop a model of the reactions they observe to describe how the total number of atoms does not change in a chemical reaction. Examples of models could include physical models, drawings, or digital forms that represent atoms. Student models ideally should have the ability to be manipulated to represent the rearrangement of reactants to products as a way to demonstrate that matter is conserved during chemical processes. Students will show how their model provides evidence that the law of conservation of matter is a mathematical description of what happens in nature.

In prior units of study, students have learned about the behavior of particles of matter during a change of state and about characteristic chemical and physical properties of matter. This unit will leverage that prior learning by having students undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes. For example, students could design a device that releases heat in a way similar to how heat is released when powdered laundry detergent is mixed with water to form a paste. Students will need to be able to track energy transfer as heat energy is either released to the environment or absorbed from the environment. Students could also design a device that absorbs and stores heat from the environment.

The design problem has already been identified; therefore, the emphasis is on designing the device, controlling the transfer of energy to the environment, and modifying the device according to factors such as type and concentration of substance. The criteria for a successful design have not been determined; therefore, teachers will need to work with students to determine criteria for a successful design. Before attempting to determine criteria, students will conduct a short research project to familiarize themselves with scientific information they can use when designing the device. Students must draw on several sources and generate additional focused questions that allow for further avenues of exploration.

After completing their research, students will compare and contrast the information gained from experiments, simulations, videos, or multimedia sources with that gained from their reading about the design of the device. Students, with the support of the teacher, will then write design criteria.

Students are now at a point where they can begin the design process. Prior to construction, students should develop a probability model and use it as part of the process for testing their device. They will use the probability model to determine which designs have the greatest probability of success.

It is important that students use mathematics appropriately when analyzing their test results. They must apply properties of operations to calculate numerical data with numbers in any form, convert between forms as appropriate, and assess the reasonableness of answers using mental computations and estimation strategies.

Students will collect and analyze these numerical data to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts

  • Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks related to chemical reactions that release energy and some that store energy.
  • Cite specific textual evidence to support analysis of science and technical texts on the design and modification of a device that controls the transfer of energy to the environment using factors such as type and concentration of a substance.
  • Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the design and modification of a device that controls the transfer of energy to the environment using factors such as type and concentration of a substance.
  • Conduct research on the design and modification of a device that controls the transfer of energy to the environment using factors such as type and concentration of a substance to answer a question (including a self-generated question), drawing on several sources and generating additional related, focused questions that allow for multiple avenues of exploration.
  • Draw evidence from informational texts to support analysis, reflection, and research on the design and modification of a device that controls the transfer of energy to the environment using factors such as type and concentration of a substance.
  • Include multimedia components and visual displays in presentations to clarify claims and findings and emphasize salient points on the design and modification of a device that controls the transfer of energy to the environment.

Mathematics

  • Integrate quantitative information expressed in words about atoms before and after a chemical process with a version of that information expressed in a physical model or drawing, including digital forms.
  • Reason quantitatively and abstractly during communication about melting or boiling points.
  • Use mathematics to model the law of conservation of matter.
  • Use ratio and rate reasoning to describe how the total number of atoms does not change in a chemical reaction, and thus mass is conserved.
  • Reason quantitatively and abstractly: Reason quantitatively using numbers to represent the criteria (amount, time, and temperature of substance) when testing a device that either releases or absorbs thermal energy by chemical processes; reason abstractly by assigning labels or symbols.
  • Collect and analyze numerical data from tests of a device that either releases or absorbs thermal energy by chemical processes. Determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success. Pose problems with positive and negative rational numbers in any form, using tools strategically. Apply properties of operations to calculate the numerical data with numbers in any form, convert between forms as appropriate, and assess the reasonableness of answers using mental computations and estimation strategies.
  • Develop a probability model and use it as part of an iterative process for testing to find the probability that a promising design solution will lead to an optimal solution. Compare probabilities from a model to observed frequencies; if the agreement is not good, explain possible sources of the discrepancy in order to ultimately develop an optimal design.

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.


Research on Student Learning

Students may think everything that exists is matter, including heat, light, and electricity.  Alternatively, they may believe that matter does not include liquids and gases or they are weightless materials. With specially designed instruction, some middle school students can learn the scientific notion of matter.

Students are deeply committed to a theory of continuous matter.  Although some students may think that substances can be divided up into small particles, they do not recognize the particles as building blocks, but as formed as basically continuous substances under certain conditions.

Students at beginning of middle school may be at different points in their conceptualization of a "theory" of matter. Although some 5th graders may start seeing weight as a fundamental property of all matter, many students in 6th and 7th grade still appear to think of weight simply as "felt weight" -- something whose weight they can't feel is considered to have no weight at all. Accordingly, some students believe that if one keeps dividing a piece of Styrofoam, one would soon obtain a piece that weighed nothing.

Students of all ages show a wide range of beliefs about the nature and behavior of particles. They lack an appreciation of the very small size of particles; attribute macroscopic properties to particles; believe there must be something in the space between particles; have difficulty in appreciating the intrinsic motion of particles in solids, liquids and gases; and have problems in conceptualizing forces between particles.  Despite these difficulties, there is some evidence that carefully designed instruction carried out over a long period of time may help middle-school students develop correct ideas about particles. (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

  • When two or more different substances are mixed, a new substance with different properties may be formed.
  • No matter what reaction or change in properties occurs, the total weight of the substances does not change. (Boundary: Mass and weight are not distinguished in fifth grade.)

Future Learning

Physical science

  • Each atom has a charged substructure consisting of a nucleus made of protons and neutrons and surrounded by electrons.
  • The periodic table orders elements horizontally according to the number of protons in nucleus of an element’s atoms and places elements with similar chemical properties in columns. The repeating patterns of this table reflect patterns of outer electron states.
  • Electrical forces within and between atoms determine the structure and interactions of matter at the bulk scale.
  • A stable molecule has less energy than the same set of atoms separated; at least this much energy must be provided in order to take the molecule apart.
  • Chemical processes, their rates, and whether or not they store or release energy can be understood in terms of the collisions of molecules and the rearrangements of atoms into new molecules, with consequent changes in the sum of all bond energies in the set of molecules that are matched by changes in kinetic energy.
  • In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present.
  • The fact that atoms are conserved, together with knowledge of the chemical properties of the elements involved, can be used to describe and predict chemical reactions.
  • Energy is a quantitative property of a system that depends on the motion and interactions of matter and radiation within that system. That there is a single quantity called energy is due to the fact that a system’s total energy is conserved even as, within the system, energy is continually transferred from one object to another and between its various possible forms.
  • At the macroscopic scale, energy manifests itself in multiple ways, such as in motion, sound, light, and thermal energy. These relationships are better understood at the microscopic scale, at which all of the different manifestations of energy can be modeled as a combination of energy associated with the motion of particles and energy associated with the configuration (relative position) of the particles.
  • In some cases, the relative position of energy can be thought of as stored in fields (which mediate interactions between particles). This last concept includes radiation, a phenomenon in which energy stored in fields moves across space.
  • Conservation of energy means that the total change of energy in any system is always equal to the total energy transferred into or out of the system.
  • Energy cannot be created or destroyed, but it can be transported from one place to another and transferred between systems.
  • Mathematical expressions, which quantify how the stored energy in a system depends on its configuration (e.g., relative positions of charged particles, compression of a spring) and how kinetic energy depends on mass and speed, allow the concept of conservation of energy to be used to predict and describe system behavior.
  • The availability of energy limits what can occur in any system.
  • Uncontrolled systems always evolve toward more stable states—that is, toward more uniform energy distribution (e.g., water flows downhill, objects hotter than their surrounding environment cool down).
  • Although energy cannot be destroyed, it can be converted to less useful forms—for example, to thermal energy in the surrounding environment.

Connections to Other Units

Grade 7 Unit 1: Properties of Matter

  • Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.
  • Solids may be formed from molecules, or they may be extended structures with repeating subunits (e.g., crystals).
  • Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it.
  • Substances react chemically in characteristic ways. In a chemical process, the atoms that make up the original substances are regrouped into different molecules, and these new substances have different properties from those of the reactants.

Grade 7 Unit 2: Interactions of Matter


Appendix A: NGSS and Foundations for the Unit

Develop and use a model to describe how the total number of atoms does not change in a chemical reaction and thus mass is conserved. [Clarification Statement: Emphasis is on law of conservation of matter and on physical models or drawings, including digital forms, that represent atoms.] [Assessment Boundary: Assessment does not include the use of atomic masses, balancing symbolic equations, or intermolecular forces.] (MS-PS1-5)

Undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes.* [Clarification Statement: Emphasis is on the design, controlling the transfer of energy to the environment, and modification of a device using factors such as type and concentration of a substance. Examples of designs could involve chemical reactions such as dissolving ammonium chloride or calcium chloride.] [Assessment Boundary: Assessment is limited to the criteria of amount, time, and temperature of substance in testing the device.] (MS-PS1-6)

Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success. (MS-ETS1-3).

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Developing and Using Models

Constructing Explanations and Designing Solutions

Analyzing and Interpreting Data

PS1.B: Chemical Reactions

ETS1.B: Developing Possible Solutions

ETS1.C: Optimizing the Design Solution

Energy and Matter

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

         Connections to Nature of Science

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

  • Laws are regularities or mathematical descriptions of natural phenomena. (MS-PS1-5)

English Language Arts

Mathematics

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content

Career Readiness Practices

CRP2 Apply appropriate academic and technical skills.

CRP4 Communicate clearly and effectively and with reason

CRP5. Consider the environmental, social and economic impacts of decisions.

CRP6. Demonstrate creativity and innovation.

CRP7. Employ valid and reliable research strategies.

CRP8 Utilize critical thinking to make sense of problems.

CRP11. Use technology to enhance productivity.


Unit 4 Summary:  Structure and Function

How do cells contribute to the functioning of an organism?

Students demonstrate age appropriate abilities to plan and carry out investigations to develop evidence that living organisms are made of cells. Students gather information to support explanations of the relationship between structure and function in cells. They are able to communicate an understanding of cell theory and understand that all organisms are made of cells. Students understand that special structures are responsible for particular functions in organisms. They then are able to use their understanding of cell theory to develop and use physical and conceptual models of cells. The crosscutting concepts of scale, proportion, and quantity and structure and function provide a framework for understanding the disciplinary core ideas. Students are expected to demonstrate proficiency in planning and carrying out investigations, analyzing and interpreting data, and developing and using models, Students are also expected to use these to use these science and engineering practices to demonstrate understanding of the disciplinary core ideas.

Student Learning Objectives

Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. [Clarification Statement: Emphasis is on developing evidence that living things are made of cells, distinguishing between living and non-living things, and understanding that living things may be made of one cell or many and varied cells.] (MS-LS1-1)  (CRP4) (CRP7) (CRP8)

Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function. [Clarification Statement: Emphasis is on the cell functioning as a whole system and the primary role of identified parts of the cell, specifically the nucleus, chloroplasts, mitochondria, cell membrane, and cell wall.] [Assessment Boundary: Assessment of organelle structure/function relationships is limited to the cell wall and cell membrane. Assessment of the function of the other organelles is limited to their relationship to the whole cell. Assessment does not include the biochemical function of cells or cell parts.] (MS-LS1-2) (CRP6) (CRP11)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 3 

Connecting with ELA/Literacy and Math p. 3

Modifications p. 4

Research on Learning p. 6

Prior Learning p. 5 

Connections to Other Courses p. 7

Sample Open Education Resources p. 8

Appendix A: NGSS and Foundations p. 9


                                       Unit Sequence

Part A: How will astrobiologists know if they have found life elsewhere in the solar system?

Concepts

Formative Assessment

  • Distinguish between living and nonliving things.
  • Cells are the smallest unit of life that can be said to be alive.
  • All living things are made up of cells, either one cell or many different numbers and types of cells.
  • Organisms may consist of one single cell (unicellular).
  • Nonliving things can be composed of cells.
  • Organisms may consist of many different numbers and types of cells (multicellular).
  • Cells that can be observed at one scale may not be observable at another scale.
  • Engineering advances have led to important discoveries in the field of cell
  • biology, and scientific discoveries have led to the development of entire industries and engineered systems.

Students who understand the concepts are able to:

  • Conduct an investigation to produce data that provides evidence distinguishing between living and nonliving things.
  • Conduct an investigation to produce data supporting the concept that living things may be made of one cell or many and varied cells.
  • Distinguish between living and nonliving things.
  • Observe different types of cells that can be found in the makeup of living things.                

                                       Unit Sequence

Part B: How do the functions of cells support an entire organism?

Concepts

Formative Assessment

  • The cell functions as a whole system.
  • Identify parts of the cell, specifically the nucleus, chloroplasts, mitochondria, cell membrane, and cell wall.
  • Within cells, special structures are responsible for particular functions.
  • Within cells, the cell membrane forms the boundary that controls what enters and leaves the cell.
  • Complex and microscopic structures and systems in cells can be visualized, modeled, and used to describe how the function of the cell depends on the relationships among its parts.
  • Complex natural structures/systems can be analyzed to determine how they function.
  • A model can be used to describe the function of a cell as a whole.
  • A model can be used to describe how parts of cells contribute to the cell’s function.
  • The structures of the cell wall and cell membrane are related to their function.

Students who understand the concepts are able to:

  • Develop and use a model to describe the function of a cell as a whole.
  • Develop and use a model to describe how parts of cells contribute to the cell’s function.
  • Develop and use models to describe the relationship between the structure and function of the cell wall and cell membrane.

What It Looks Like in the Classroom

This unit of study begins with students distinguishing between living and nonliving things. Students will conduct investigations examining both living and nonliving things and using the data they collect as evidence for making this distinction. During this investigation, students will study living things that are made of cells, either one cell or many different numbers and types of cells.

Students will also study nonliving things, some of which are made up of cells. Students will understand that life is a quality that distinguishes living things—composed of living cells—from once-living things that have died or things that never lived. Emphasis is on students beginning to understand the cell theory by developing evidence that living things are made of cells, distinguishing between living and nonliving things, and understanding that living things may be made of one cell or many and varied cells.

Students will pose a question drawn from their investigations and draw on several sources to generate additional related, focused questions that allow for multiple avenues of exploration. They will conduct a short research project to collect evidence to develop and support their answers to the questions they generate. The report created from their research will integrate multimedia and visual displays of cells and specific cell parts into a presentation that will clarify the answers to their questions. Students will include in their reports variables representing two quantities, such as the number of cells that makes up an organism and units representing the size or type of the organism, and their conclusion about the relationship between these two variables. They will write an equation to express one quantity, thought of as the dependent variable, in terms of the other quantity, thought of as the independent variable. Students will analyze the relationship between the dependent and independent variables using graphs and tables and relate the graphs and tables to the equation.

As a continuation of their study of the cell, students will study the structure of the cell. This study begins with thinking of the cell as a system that is made up of parts, each of which has a function that contributes to the overall function of the cell. Students will learn that within cells, special structures—such as the nucleus, chloroplasts, mitochondria, cell membrane, and cell wall—are responsible for particular functions. It is important to remember that students are required only to study the functions of these organelles in terms of how they contribute to the overall function of the cell, not in terms of their biochemical functions.

As part of their learning about the structure of the cell, students use models as a way of visualizing and representing structures that are microscopic. Students will develop and use a model to describe the function of the cell as a whole and the ways parts of the cell contribute to the cell’s function. Models can be made of a variety of materials, including student-generated drawings, digital representations, or 3-D structures.

Students will examine the structure and function relationship of the cell membrane and the cell wall. They will learn that the structure of the cell membrane makes it possible for it to form the boundary that controls what enters and leaves the cell. They will also learn that the structure of the cell wall makes it possible for it to serve its function. This study of the relationship between structure and function will be limited to the cell wall and cell membrane. Students will use variables to represent two quantities that describe some attribute of at least one structure of the cell—for example, how the surface area of a cell changes in relation to a change in the volume cell’s volume. Students will write an equation to express the dependent variable in terms of the independent variable, and they will analyze the relationship between the dependent and independent variables using graphs and tables and relate these to the equation.

Throughout this unit, students will learn that some of the structures of the cell are visible when studied under certain magnification while others are and that engineering discoveries are making many new industries possible.

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts

  • Conduct a short research project collecting evidence that living things are made of cells to answer a question (including a self-generated question). Draw on several sources and generate additional related, focused questions that allow for multiple avenues of exploration.
  • Integrate multimedia and visual displays of cells and specific cell parts into presentations to clarify information, strengthen claims and evidence, and add interest.

Mathematics

  • Use variables to represent two quantities, such as the number of cells that makes up an organism and units representing the size or type of the organism, and determine the relationship between these two variables.
  • Write an equation to express one quantity, thought of as the dependent variable, in terms of the other quantity, thought of as the independent variable. Analyze the relationship between the dependent and independent variables using graphs and tables, and relate these to the equation.
  • Use variables to represent two quantities in a real-world problem that change in relationship to one another—for example, determining the ratio of a cell’s surface area to its volume. Write an equation to express one quantity, thought of as the dependent variable, in terms of the other quantity, thought of as the independent variable. Analyze the relationship between the dependent and independent variables using graphs and tables, and relate these to the equation.

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.

Research on Student Learning

Preliminary research indicates that it may be easier for students to understand that the cell is the basic unit of structure (which they can observe) than that the cell is the basic unit of function (which has to be inferred from experiments). Research also shows that high-school students may hold various misconceptions about cells after traditional instruction. (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

  • Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction.

Future Learning

Life science

  • Systems of specialized cells within organisms help cells perform the essential functions of life.
  • All cells contain genetic information in the form of DNA molecules. Genes are regions in the DNA that contain the instructions that code for the formation of proteins, which carry out most of the work of cells.
  • Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level.
  • Feedback mechanisms maintain a living system’s internal conditions within certain limits and mediate behaviors, allowing the system to remain alive and functional even as external conditions change within some range. Feedback mechanisms can encourage (through positive feedback) or discourage (through negative feedback) what is going on inside the living system.

Connections to Other Units

Grade 7 Unit 6: Inheritance and Variation of Traits

Grade 7 Unit 8: Earth Systems


Appendix A: NGSS and Foundations for the Unit

Conduct an investigation to provide evidence that living things are made of cells; either one cell or many different numbers and types of cells. [Clarification Statement: Emphasis is on developing evidence that living things are made of cells, distinguishing between living and non-living things, and understanding that living things may be made of one cell or many and varied cells.] (MS-LS1-1)

Develop and use a model to describe the function of a cell as a whole and ways parts of cells contribute to the function. [Clarification Statement: Emphasis is on the cell functioning as a whole system and the primary role of identified parts of the cell, specifically the nucleus, chloroplasts, mitochondria, cell membrane, and cell wall.] [Assessment Boundary: Assessment of organelle structure/function relationships is limited to the cell wall and cell membrane. Assessment of the function of the other organelles is limited to their relationship to the whole cell. Assessment does not include the biochemical function of cells or cell parts.] (MS-LS1-2)

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Planning and Carrying Out Investigations

LS1.A: Structure and Function

Scale, Proportion, and Quantity

Structure and Function

   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

Connections to Engineering, Technology and Applications of Science

Interdependence of Science, Engineering, and Technology

  • Engineering advances have led to important discoveries in virtually every field of science, and scientific discoveries have led to the development of entire industries and engineered systems. (MS-LS1-1)

English Language Arts

Mathematics

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content

Career Readiness Practices

CRP4. Communicate clearly and effectively and with reason.

CRP6. Demonstrate creativity and innovation.

CRP8. Utilize critical thinking to make sense of problems.

CRP11. Use technology to enhance productivity.


Unit 5 Summary:  Body Systems

What are humans made of?

Students develop a basic understanding of the role of cells in body systems and how those systems work to support the life functions of the organism. Students will construct explanations for the interactions of systems in cells and organisms. Students understand that special structures are responsible for particular functions in organisms, and that for many organisms, the body is a system of multiple-interaction subsystems that form a hierarchy, from cells to the body. Students construct explanations for the interactions of systems in cells and organisms and for how organisms gather and use information from the environment. The crosscuttings concepts of systems and system models and cause and effect provide a framework for understanding the disciplinary core ideas. Students are expected to demonstrate proficiency in engaging in argument from evidence and obtaining, evaluating, and communicating information. Students use these science and engineering practices to demonstrate understanding of the disciplinary core ideas.

Student Learning Objectives

Use argument supported by evidence for how the body is a system of interacting subsystems composed of groups of cells. [Clarification Statement: Emphasis is on the conceptual understanding that cells form tissues and tissues form organs specialized for particular body functions. Examples could include the interaction of subsystems within a system and the normal functioning of those systems.] [Assessment Boundary: Assessment does not include the mechanism of one body system independent of others. Assessment is limited to the circulatory, excretory, digestive, respiratory, muscular, and nervous systems.] (MS-LS1-3) (CRP2) (CRP4) (CRP11)

Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories. [Assessment Boundary: Assessment does not include mechanisms for the transmission of this information.] (MS-LS1-8) (CRP 7) (CRP8) (CRP11)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 3 

Connecting with ELA/Literacy and Math p. 3

Modifications p. 4

Research on Learning p. 6

Prior Learning p. 5 

Connections to Other Courses p. 7

Sample Open Education Resources p. 8

Appendix A: NGSS and Foundations p. 9


                                       Unit Sequence

Part A: What is the evidence that a body is actually a system of interacting subsystems composed of groups of interacting cells?

Concepts

Formative Assessment

  • In multicellular organisms, the body is a system of multiple, interacting subsystems.
  • Subsystems are groups of cells that work together to form tissues.
  • Organs are groups of tissues that work together to perform a particular body function.
  • Tissues and organs are specialized for particular body functions.
  • Systems may interact with other systems.
  • Systems may have subsystems and be part of larger complex systems.
  • Interactions are limited to the circulatory, excretory, digestive, respiratory, muscular, and nervous systems.
  • Scientists and engineers are guided by habits of mind such as intellectual honesty, tolerance of ambiguity, skepticism, and openness to new ideas.

Students who understand the concepts are able to:

  • Use an oral and written argument supported by evidence to support or refute an explanation or a model of how the body is a system of interacting subsystems composed of groups of cells.                

                                       Unit Sequence

Part B: How do organisms receive and respond to information from their environment?

Concepts

Formative Assessment

  • Sense receptors respond to different inputs (electromagnetic, mechanical, chemical).
  • Sense receptors transmit responses as signals that travel along nerve cells to the brain.
  • Signals are then processed in the brain.
  • Brain processing results in immediate behaviors or memories.
  • Cause-and-effect relationships may be used to predict response to stimuli in natural systems.

Students who understand the concepts are able to:

  • Gather, read, and synthesize information from multiple appropriate sources about sensory receptors’ response to stimuli.
  • Assess the credibility, accuracy, and possible bias of each publication and methods used.
  • Describe how publications and methods used are supported or not supported by evidence.

What It Looks Like in the Classroom

 Within this unit, students will use informational text and models to support their understanding that the body is a system of interacting subsystems. Instruction should begin with students understanding that the cell is a specialized structure that is a functioning system. Students will need to understand that different types of cells have different functions; therefore, each cell system is specialized to perform its particular function. Building on this understanding, students learn that different types of cells serve as subsystems for larger systems called tissues. Groups of specialized tissues serve as subsystems for organs that then serve as subsystems for body systems such as the circulatory, excretory, digestive, respiratory, muscular, and nervous systems. Students need to understand how each body system interacts with other body systems. Emphasis is on the conceptual understanding that each system and subsystem is specialized for particular body functions; it does not include the mechanisms of one body system independent of others.

As part of their investigation of how body systems are interrelated, students should use variables to represent two quantities that describe how the inputs or outputs of one system change in relationship to another. They should write an equation to express one quantity, thought of as the dependent variable, in terms of the other quantity, thought of as the independent variable; analyze the relationship using graphs and tables; and relate these to the equation. For example, students can find the relationship between increased activity of the muscular system and the related increase in the activity of the circulatory or respiratory system and express this relationship as an equation.

Students will demonstrate their understanding of this concept by writing an argument, supported by evidence, to support an explanation of how the body is a system of interacting subsystems. As part of their preparation for this written argument, students will read science resources and analyze the evidence used to support arguments in these resources. While gathering evidence, it is important that students connect to the nature of science by demonstrating scientific habits. They should be sure to display intellectual honesty by ensuring that whenever they cite specific textual information and quote or paraphrase the data and conclusions of others, they avoid plagiarism and provide basic bibliographic information for sources.

Students will deepen their understanding of subsystems by gathering and synthesizing information about sensory receptors. Students will understand that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories. Each sensory receptor responds to different inputs (electromagnetic, mechanical, chemical), transmitting them as signals that travel along nerve cells to the brain. Each response can be examined as a cause-and-effect relationship that can be used to predict response to stimuli in natural systems. Each step in the stimulus/response pathway can be connected to students’ previous study of systems and subsystems. For example, the nervous system includes receptors that are subsystems that respond to stimuli by sending messages to the brain.

Using multiple appropriate sources, students will read and synthesize information and will assess the credibility, accuracy, and possible bias of publications and methods used, and describe how the information they read is or is not supported by evidence. For example, students could participate in class discussions in which they can investigate whether information they have read in publications agree with scientific findings or seem to be biased in order to advertise a product or support a position.

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts

  • Cite specific textual evidence to support analysis of science and technical texts that provide evidence for how the body is a system of interacting subsystems composed of cells.
  • Trace and evaluate a text’s argument that the body is a system of interacting subsystems composed of cells, distinguishing claims that are supported by reasons and evidence from claims that are not.
  • Write arguments, supported by evidence, for how the body is a system of interacting subsystems composed of groups of cells.
  • Gather relevant information concerning how sensory receptors function by responding to stimuli, then sending messages to the brain, which responds immediately through some form or behavior or by storing the messages as memory. Quote or paraphrase the data and conclusions of others while avoiding plagiarism and providing basic bibliographic information for sources.

Mathematics

  • N/A

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.

Research on Student Learning

Preliminary research indicates that it may be easier for students to understand that the cell is the basic unit of structure (which they can observe) than that the cell is the basic unit of function (which has to be inferred from experiments). Research also shows that high-school students may hold various misconceptions about cells after traditional instruction (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

  • Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction.

Future Learning

Life science

  • Systems of specialized cells within organisms help the organisms perform the essential functions of life.
  • All cells contain genetic information in the form of DNA molecules. Genes are regions in DNA that contain the instructions that code for the formation of proteins, which carry out most of the work of cells.
  • Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level.
  • Feedback mechanisms maintain a living system’s internal conditions within certain limits and mediate behaviors, allowing the living systems to remain alive and functional even as external conditions change, within some range. Feedback mechanisms can encourage (through positive feedback) or discourage (through negative feedback) what is going on inside the living system.

Connections to Other Units

Grade 7 Unit 4: Structure and Function

Grade 7 Unit 6: Inheritance and Variation of Traits


Appendix A: NGSS and Foundations for the Unit

Use argument supported by evidence for how the body is a system of interacting subsystems composed of groups of cells. [Clarification Statement: Emphasis is on the conceptual understanding that cells form tissues and tissues form organs specialized for particular body functions. Examples could include the interaction of subsystems within a system and the normal functioning of those systems.] [Assessment Boundary: Assessment does not include the mechanism of one body system independent of others. Assessment is limited to the circulatory, excretory, digestive, respiratory, muscular, and nervous systems.] (MS-LS1-3)

Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories. [Assessment Boundary: Assessment does not include mechanisms for the transmission of this information.] (MS-LS1-8)

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Obtaining, Evaluating, and Communicating Information

Engaging in Argument from Evidence

LS1.A: Structure and Function

LS1.D: Information Processing

Systems and System Models

Cause and Effect

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

         Connections to Nature of Science

 Science is a Human Endeavor

  • Scientists and engineers are guided by habits of mind such as intellectual honesty, tolerance of ambiguity, skepticism, and openness to new ideas. (MS-LS1-3)

English Language Arts

Mathematics

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content.

N/A

Career Readiness Practices

CRP2. Apply appropriate academic and technical skills.

CRP4. Communicate clearly and effectively and with reason. .

CRP7. Employ valid and reliable research strategies.

CRP8. Utilize critical thinking to make sense of problems.

CRP11. Use technology to enhance productivity.


Unit 6 Summary:  Inheritance and Variations of Traits

Why do kids look similar to their parents?

Students develop and use models to describe how gene mutations and sexual reproduction contribute to genetic variation. Students understand how genetic factors determine the growth of an individual organism. They also demonstrate understanding of the genetic implications of sexual and asexual reproduction. The crosscutting concepts of cause and effect and structure and function provide a framework for understanding how gene structure determines differences in the functioning of organisms. Students are expected to demonstrate proficiency in developing and using models. Students use these science and engineering practices to demonstrate understanding of the disciplinary core ideas.

Student Learning Objectives

Develop and use a model to describe why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism. [Clarification Statement: Emphasis is on conceptual understanding that changes in genetic material may result in making different proteins.] [Assessment Boundary: Assessment does not include specific changes at the molecular level, mechanisms for protein synthesis, or specific types of mutations.] (MS-LS3-1) (CRP2) (CRP5) (CRP7) (CRP11)

Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation. [Clarification Statement: Emphasis is on using models such as Punnett squares, diagrams, and simulations to describe the cause and effect relationship of gene transmission from parent(s) to offspring and resulting genetic variation.] (MS-LS3-2) (CRP2) (CRP5) (CRP7) (CRP11)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 3 

Connecting with ELA/Literacy and Math p. 3

Modifications p. 4

Research on Learning p. 6

Prior Learning p. 5 

Connections to Other Courses p. 7

Sample Open Education Resources p. 8

Appendix A: NGSS and Foundations p. 9

                                       Unit Sequence

Part A: How do structural changes to genes (mutations) located on chromosomes affect proteins or affect the structure and function of an organism?

Concepts

Formative Assessment

  • Complex and microscopic structures and systems, such as genes located on chromosomes, can be visualized, modeled, and used to describe how their function depends on the shapes, composition, and relationships among the parts of the system; therefore, complex natural structures/systems can be analyzed to determine how they function.
  • Genes are located in the chromosomes of cells, with each chromosome pair containing two variants of each of many distinct genes.
  • Each distinct gene chiefly controls the production of specific proteins, which in turn affect the traits of the individual.
  • In addition to variations that arise from sexual reproduction, genetic information can be altered due to mutations.
  • Some changes to genetic material are beneficial, others harmful, and some neutral to the organism.
  • Changes in genetic material may result in the production of different proteins.
  • Changes (mutations) to genes can result in changes to proteins, which can affect the structures and functions of the organism and thereby change traits.
  • Structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism
  • Though rare, mutations may result in changes to the structure and function of proteins.

Students who understand the concepts are able to:

  • Develop and use a model to describe why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism.                

                                       Unit Sequence

Part B: How do asexual reproduction and sexual reproduction affect the genetic variation of offspring?

Concepts

Formative Assessment

  • Organisms reproduce either sexually or asexually and transfer their genetic information to their offspring.
  • Asexual reproduction results in offspring with identical genetic information.
  • Sexual reproduction results in offspring with genetic variation.
  • Variations of inherited traits between parent and offspring arise from genetic differences that result from the subset of chromosomes (and therefore genes) inherited.
  • In sexually reproducing organisms, each parent contributes half of the genes acquired (at random) by the offspring.
  • Individuals have two of each chromosome and hence two alleles of each gene, one acquired from each parent. These versions may be identical or may differ from each other.
  • Punnett squares, diagrams, and simulations can be used to describe the cause-and-effect relationship of gene transmission from parent(s) to offspring and resulting genetic variation.

Students who understand the concepts are able to:

  • Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information.
  • Develop and use a model to describe why sexual reproduction results in offspring with genetic variation.
  • Use models such as Punnett squares, diagrams, and simulations to describe the cause-and effect-relationship of gene transmission from parent(s) to offspring and resulting genetic variation.

What It Looks Like in the Classroom

Using models, such as electronic simulations, physical models, or drawings, students will learn that genes are located in the chromosomes of cells and each chromosome pair contains two variants of each gene. Students will need to make distinctions between chromosomes and genes and understand the connections between them. DNA will be introduced in high school. Students will learn that chromosomes are the genetic material that is found in the nucleus of the cell and that chromosomes are made up of genes. They will also learn that each gene chiefly controls the production of specific proteins, which in turn affect the traits of the individual.

Students should be given opportunities to use student-developed conceptual models to visualize how a mutation of genetic material could have positive, negative, or neutral impact on the expression of traits in organisms. Emphasis in this unit is on conceptual understanding that mutations of the genetic material may result in making different proteins; therefore, models and activities that focus on the expression of genetic traits, rather than on the molecular-level mechanisms for protein synthesis or specific types of mutations, are important for this unit of study. For example, models that assign genetic information to specific segments of model chromosomes could be used. Students could add, remove, or exchange genes located on the chromosomes and see that changing or altering a gene can result in a change in gene expression (proteins and therefore traits).

Students will continue this unit of study by describing two of the most common sources of genetic variation, sexual and asexual reproduction. Students will be able to show that in sexual reproduction, each parent contributes half of the genes acquired by offspring, whereas in asexual reproduction, a single parent contributes the genetic makeup of offspring. Using models such as Punnett squares, diagrams, and simulations, students will describe the cause-and-effect relationship between gene transmission from parents(s) to offspring and the resulting genetic variation. Using symbols to represent the two alleles of a gene, one acquired from each parent, students can use Punnett squares to model how sexual reproduction results in offspring that may or may not have a genetic makeup that is different from either parent. Students can observe the same mixing of genetic information using colored counters or electronic simulations. Using other models, students can show that asexual reproduction results in offspring with the same combination of genetic information as the parents.

Students can summarize the numerical data they collect during these activities as part of their description of why asexual reproduction results in offspring with identical genetic combinations and sexual reproduction results in offspring with genetic variations. As a culmination of this unit of study, students could make multimedia presentations to demonstrate their understanding of the key concepts. Students could participate in a short research project and cite the specific textual evidence used to support the analysis of any scientific information they gather. They could integrate quantitative or technical information as part of their presentation. For example, students can take data collected during investigations of genetic mutations and provide a narrative description of their results. They could use data collected during their investigation of sexual and asexual reproduction. They could also include diagrams, graphs, or tables to clarify their data.

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts

  • Cite specific textual evidence to support analysis of science and technical texts about structural changes to genes (mutations) located on chromosomes that may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism.
  • Determine the meaning of symbols, key terms, and other domain-specific phrases as they are used to describe why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism.
  • Integrate quantitative or technical information about why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism that is expressed in words with a version of that information expressed visually in a flowchart, diagram, model, graph, or table.
  • Include multimedia components and visual displays in presentations about structural changes to genes (mutations) located on chromosomes that may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism to clarify claims and findings and emphasize salient points.
  • Cite specific textual evidence for why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation to support analysis of science and technical texts.
  • Determine the meaning of symbols, key terms, and other domain-specific phrases as they are used to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation.
  • Integrate quantitative or technical information that describes why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation that is expressed in words with a version of that information that is expressed visually in a flowchart, diagram, model, graph, or table.
  • Include multimedia components and visual displays in presentations that describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation to clarify claims and findings and emphasize salient points.

Mathematics

  • Use mathematics to model why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation.
  • Summarize numerical data sets that describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation in relation to their context.

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.

Research on Student Learning

When asked to explain how physical traits are passed from parents to offspring, elementary-school, middle-school, and some high-school students express the following misconceptions: Some students believe that traits are inherited from only one of the parents (for example, the traits are inherited from the mother, because she gives birth or has most contact as children grow up; or the same-sex parent will be the determiner). Other students believe that certain characteristics are always inherited from the mother and others come from the father. Some students believe in a "blending of characteristics." It may not be until the end of 5th grade that some students can use arguments based on chance to predict the outcome of inherited characteristics of offspring from observing those characteristics in the parents.

Early middle-school students explain inheritance only in observable features, but upper middle-school and high-school students have some understanding that characteristics are determined by a particular genetic entity which carries information translatable by the cell. Students of all ages believe that some environmentally produced characteristics can be inherited, especially over several generations.

By the end of 5th grade, students know that babies result from the fusion of sperm and eggs. However, they often don't understand how the fusion brings new life. Before students have an early understanding of genetics, they may believe that the baby exists in the sperm but requires the egg for food and protection, or that the baby exists in the egg and requires the sperm as trigger to growth (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

  • Many characteristics of organisms are inherited from parents.
  • Other characteristics result from individuals’ interactions with the environment, which can range from diet to learning. Many characteristics involve both inheritance and environment.
  • Different organisms vary in how they look and function because they have different inherited information.
  • The environment also affects the traits that an organism develops.

Future Learning

Life science

  • Systems of specialized cells within organisms help the organisms perform the essential functions of life.
  • All cells contain genetic information in the form of DNA molecules. Genes are regions in the DNA that contain the instructions that code for the formation of proteins, which carry out most of the work of cells.
  • Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level.
  • Feedback mechanisms maintain a living system’s internal conditions, within certain limits, and mediate behaviors, allowing the system to remain alive and functional even as external conditions change, within some range. Feedback mechanisms can encourage (through positive feedback) or discourage (through negative feedback) what is going on inside the living system.
  • In multicellular organisms, individual cells grow and then divide via a process called mitosis, thereby allowing the organism to grow. The organism begins as a single cell (fertilized egg) that divides successively to produce many cells, with each parent cell passing identical genetic material (two variants of each chromosome pair) to both daughter cells. Cellular division and differentiation produce and maintain a complex organism, composed of systems of tissues and organs that work together to meet the needs of the whole organism.
  • Each chromosome consists of a single, very long DNA molecule, and each gene on the chromosome is a particular segment of that DNA. The instructions for forming species’ characteristics are carried in DNA. All cells in an organism have the same genetic content, but the genes used (expressed) by the cell may be regulated in different ways. Not all DNA codes for a protein; some segments of DNA are involved in regulatory or structural functions, and some have, as yet, no known function.
  • In sexual reproduction, chromosomes can sometimes swap sections during the process of meiosis (cell division), thereby creating new genetic combinations and thus more genetic variation. Although DNA replication is tightly regulated and remarkably accurate, errors do occur and result in mutations, which are also a source of genetic variation. Environmental factors can also cause mutations in genes, and viable mutations are inherited.
  • Environmental factors also affect expression of traits, and hence affect the probability of occurrences of traits in a population. Thus the variation and distribution of traits observed depends on both genetic and environmental factors.

Connections to Other Units

Grade 6 Unit 1: Growth, Development and Reproduction of Organisms

Grade 7 Unit 4: Structure and Function

Grade 8 Unit 2: Selection and Adaptation


Appendix A: NGSS and Foundations for the Unit

Develop and use a model to describe why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism. [Clarification Statement: Emphasis is on conceptual understanding that changes in genetic material may result in making different proteins.] [Assessment Boundary: Assessment does not include specific changes at the molecular level, mechanisms for protein synthesis, or specific types of mutations.] (MS-LS3-1)

Develop and use a model to describe why asexual reproduction results in offspring with identical genetic information and sexual reproduction results in offspring with genetic variation. [Clarification Statement: Emphasis is on using models such as Punnett squares, diagrams, and simulations to describe the cause and effect relationship of gene transmission from parent(s) to offspring and resulting genetic variation.] (MS-LS3-2)

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Developing and Using Models

  • Develop and use a model to describe phenomena. (MS-LS3-1),(MS-LS3-2)

LS1.B: Growth and Development of Organisms

LS3.A: Inheritance of Traits

LS3.B: Variation of Traits

Structure and Function

Cause and Effect

English Language Arts

Mathematics

  • Cite specific textual evidence to support analysis of science and technical texts. (MS-LS3-1),(MS-LS3-2) RST.6-8.1
  • Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6-8 texts and topics. (MS-LS3-1),(MS-LS3-2) RST.6-8.4
  • Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table). (MS-LS3-1),(MS-LS3-2) RST.6-8.7
  • Integrate multimedia and visual displays into presentations to clarify information, strengthen claims and evidence, and add interest. (MS-LS3-1),(MS-LS3-2) SL.8.5

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content.

Career Readiness Practices

CRP2. Apply appropriate academic and technical skills.

CRP5. Consider the environmental, social and economic impacts of decisions.

CRP7. Employ valid and reliable research strategies.

CRP11. Use technology to enhance productivity.


Unit 7 Summary:  Organization of Matter and Energy Flow in Organisms

How do some organisms turn electromagnetic radiation into matter and energy?

Students provide a mechanistic account for how cells provide a structure for the plant process of photosynthesis in the movement of matter and energy needed for the cell. Students use conceptual and physical models to explain the transfer of energy and cycling of matter as they construct explanations for the role of photosynthesis in cycling matter in ecosystems. They construct scientific explanations for the cycling of matter in organisms and the interactions of organisms to obtain matter and energy from an ecosystem to survive and grow. They understand that sustaining life requires substantial energy and matter inputs, and that the structure and functions of organisms contribute to the capture, transformation, transport, release, and elimination of matter and energy. The crosscutting concepts of matter and energy and structure and function provide a framework for understanding of the cycling of matter and energy flow into and out of organisms. Students are also expected to demonstrate proficiency in developing and using models. Students use these science and engineering practices to demonstrate understanding of the disciplinary core ideas. 

Student Learning Objectives

Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms. [Clarification Statement: Emphasis is on tracing movement of matter and flow of energy.] [Assessment Boundary: Assessment does not include the biochemical mechanisms of photosynthesis.] (MS-LS1-6) (CRP2) (CRP4) (CRP7) (CRP11)

Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism. [Clarification Statement: Emphasis is on describing that molecules are broken apart and put back together and that in this process, energy is released.] [Assessment Boundary: Assessment does not include details of the chemical reactions for photosynthesis or respiration.] (MS-LS1-7) (CRP2) (CRP6) (CRP7)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 3 

Connecting with ELA/Literacy and Math p. 3

Modifications p. 4

Research on Learning p. 6

Prior Learning p. 5 

Connections to Other Courses p. 7

Sample Open Education Resources p. 8

Appendix A: NGSS and Foundations p. 9

                                       Unit Sequence

Part A: What is the role of photosynthesis in the cycling of matter and flow of energy into and out of an organism?

Concepts

Formative Assessment

  • Photosynthesis has a role in the cycling of matter and flow of energy into and out of organisms.
  • The flow of energy and cycling of matter can be traced.
  • 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.
  • 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.
  • Sugars produced by plants can be used immediately or stored for growth or later use.
  • Within a natural system, the transfer of energy drives the motion and/or cycling of matter.

Students who understand the concepts are able to:

  • Construct a scientific explanation for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms based on valid and reliable evidence obtained from sources (including the students’ own experiments).
  • Construct a scientific explanation for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms based on 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.        

                                       Unit Sequence

Part B: How is food rearranged through chemical reactions to form new molecules that support growth and/or release energy as this matter moves through an organism?

Concepts

Formative Assessment

  • Food is rearranged through chemical reactions, forming new molecules that support growth.
  • Food is rearranged through chemical reactions, forming new molecules that release energy as this matter moves through an organism.
  • Molecules are broken apart and put back together to form new substances, and in this process, energy is released.
  • Cellular respiration in plants and animals involves chemical reactions with oxygen that release stored energy.
  • In cellular respiration, complex molecules containing carbon react with oxygen to produce carbon dioxide and other materials.
  • 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.
  • Matter is conserved during cellular respiration because atoms are conserved in physical and chemical processes.

Students who understand the concepts are able to:

  • Develop and use a model to describe how food is rearranged through chemical reactions.

What It Looks Like in the Classroom

Students will construct explanations about the role of photosynthesis using evidence obtained from sources, including the students’ own experiments or outside sources. Student-constructed informative/explanatory responses will cite specific textual evidence, determine the central ideas to support their analysis, and provide an accurate summary distinct from their own prior knowledge or opinions. Some experiments could include observing elodea releasing oxygen, depriving a plant of sunlight or water, or using glucose test strips. In this unit of study, emphasis is on the transfer of energy that drives the motion and/or cycling of matter.

Students can represent the matter and energy involved in the process of photosynthesis using the equation for this reaction. Using this equation, students can build ball-and-stick models to show how carbon dioxide and water are rearranged to form glucose. Students can also draw conclusions about the cycling of matter and the flow of energy by observing plants such as elodea. By contrasting elodea plants in a variety of controlled environments, students can draw conclusions about how carbon dioxide and oxygen enter and leave organisms.

Students could also perform investigations where the input of light energy is manipulated. In these investigations, students can observe that even if the matter required for photosynthesis is present, the process will not proceed if light energy is not available. If light is available, students will be able to test the leaves of certain plants for the presence of stored sugar in the form of starch. If light is not available, students will observe that the sugars are not stored as starch in the leaves. This will emphasize that the transfer of light energy drives the cycling of matter into chemical energy. Students can also trace the flow of energy using models such as energy pyramids.

Using the data collected during their investigations and observations of simulations, students construct an explanation for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms. They could participate in s short research project in which they will use textual evidence to support their analysis. As part of their research, students will provide an accurate summary of the text they use and determine the central ideas or conclusions of the text. They can they write informative or explanatory texts to explain the process. As a result of their research, students should be able to observe that the information they gather through research supports their scientific observations. They could then make predictions about the impact of different environmental changes on the cycling of matter and flow of energy. For example, students could make predictions about the impact that volcanic eruptions that produce massive clouds of sunlight-blocking ash that linger long periods of time could have on life in the affected area.

Student learning will progress to developing and using models to describe how food is rearranged through chemical reactions. These reactions form new molecules that support growth and/or release energy as the matter moves through an organism. Students can integrate multimedia and visual displays into models to clarify information, strengthen claims and evidence, and add interest. Emphasis is on describing that molecules are broken apart and reassembled and that in this process, energy is released. Student models will demonstrate that matter is conserved in cell respiration. Models can be created using materials similar to those used in students’ photosynthesis models, thereby emphasizing the complementary nature of photosynthesis and cellular respiration. Students can also act out the roles of variables within the chemical-reaction rearrangement to deepen their understanding.

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts

  • Cite specific textual evidence to support analysis of science and technical texts about the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.
  • Determine the central ideas about the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms or conclusions of a text; provide an accurate summary of the text distinct from prior knowledge or opinion.
  • Write informative/explanatory texts to examine the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms, and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content.
  • Draw evidence from informational texts to support analysis, reflection, and research about the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.
  • Integrate multimedia and visual displays into presentations about how food is rearranged through chemical reactions to form new molecules that support growth and/or release energy as the matter moves through an organism to clarify information, strengthen claims and evidence, and add interest.

Mathematics

  • Use variables to represent two quantities involved in the process whereby photosynthesis plays a part in the cycling of matter and energy into and out of organisms. Write an equation to express one quantity, thought of as the dependent variable, in terms of the other quantity, thought of as the independent variable. Analyze the relationship between the dependent and independent variables using graphs and tables, and relate these to the equation.

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.

Research on Student Learning

Students of all ages see food as substances (water, air, minerals, etc.) that organisms take directly in from their environment. In addition, some students of all ages think food is a requirement for growth, rather than a source of matter for growth. They have little knowledge about food being transformed and made part of a growing organism's body.

Some students of all ages hold misconceptions about plant nutrition. They think plants get their food from the environment rather than manufacturing it internally, and that food for plants is taken in from the outside. These misconceptions are particularly resistant to change. Even after traditional instruction, students have difficulty accepting that plants make food from water and air, and that this is their only source of food. Understanding that the food made by plants is very different from other nutrients such as water or minerals is a prerequisite for understanding the distinction between plants as producers and animals as consumers (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

  • The energy released [from] food was once energy from the sun that was captured by plants in the chemical process that forms plant matter (from air and water).
  • Food provides animals with the materials they need for body repair and growth and the energy they need to maintain body warmth and for motion.
  • The food of almost any kind of animal can be traced back to plants.
  • Organisms are related in food webs in which some animals eat plants for food and other animals eat the animals that eat plants.
  • Some organisms, such as fungi and bacteria, break down dead organisms (both plants or plants parts and animals) and therefore operate as “decomposers.” Decomposition eventually restores (recycles) some materials back to the soil.
  • Organisms can survive only in environments in which their particular needs are met.
  • A healthy ecosystem is one in which multiple species of different types are each able to meet their needs in a relatively stable web of life.
  • Newly introduced species can damage the balance of an ecosystem.
  • Matter cycles between the air and soil and among plants, animals, and microbes as these organisms live and die.
  • Organisms obtain gases and water from the environment and release waste matter (gas, liquid, or solid) back into the environment.

Future Learning

Physical science

  • Chemical processes, their rates, and whether or not energy is stored or released can be understood in terms of the collisions of molecules and the rearrangements of atoms into new molecules, with consequent changes in the sum of all bond energies in the set of molecules that are matched by changes in kinetic energy.
  • In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present.
  • The fact that atoms are conserved, together with knowledge of the chemical properties of the elements involved, can be used to describe and predict chemical reactions.

Life science

  • The process of photosynthesis converts light energy into stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.
  • The sugar molecules thus formed contain carbon, hydrogen, and oxygen; their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules (such as proteins or DNA), used, for example, to form new cells.
  • As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.
  • As a result of these chemical reactions, energy is transferred from one system of interacting molecules to another.
  • Cellular respiration is a chemical process in which the bonds of food molecules and oxygen molecules are broken and new compounds that can transport energy to muscles are formed.
  • Cellular respiration releases the energy needed to maintain body temperature despite ongoing energy transfer to the surrounding environment.
  • Photosynthesis and cellular respiration (including anaerobic processes) provide most of the energy for life processes.
  • Plants or algae form the lowest level of the food web.
  • At each link upward in a food web, only a small fraction of the matter consumed at the lower level is transferred upward to produce growth and release energy in cellular respiration at the higher level. Given this inefficiency, there are generally fewer organisms at higher levels of a food web.
  • Some matter reacts to release energy for life functions, some matter is stored in newly made structures, and much is discarded.
  • The chemical elements that make up the molecules of organisms pass through food webs and into and out of the atmosphere and soil, and they are combined and recombined in different ways.
  • At each link in an ecosystem, matter and energy are conserved.
  • Photosynthesis and cellular respiration are important components of the carbon cycle, in which carbon is exchanged among the biosphere, atmosphere, oceans, and geosphere through chemical, physical, geological, and biological processes.

Earth and space science

  • The foundation for Earth’s global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, ocean, and land systems, and this energy’s re-radiation into space.
  • Gradual atmospheric changes were due to plants and other organisms that captured carbon dioxide and released oxygen.
  • Changes in the atmosphere due to human activity have increased carbon dioxide concentrations and thus affect climate.

Connections to Other Units

Grade 7 Unit 3: Chemical Reactions

Grade 7 Unit 4: Structure and Function

Grade 7 Unit 8: Earth Systems


Appendix A: NGSS and Foundations for the Unit

Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms. [Clarification Statement: Emphasis is on tracing movement of matter and flow of energy.] [Assessment Boundary: Assessment does not include the biochemical mechanisms of photosynthesis.] (MS-LS1-6)

Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism. [Clarification Statement: Emphasis is on describing that molecules are broken apart and put back together and that in this process, energy is released.] [Assessment Boundary: Assessment does not include details of the chemical reactions for photosynthesis or respiration.] (MS-LS1-7)

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Developing and Using Models

Constructing Explanations and Designing Solutions

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

         Connections to Nature of Science 

Scientific Knowledge is Based on Empirical Evidence

  • Science knowledge is based upon logical connections between evidence and explanations. (MS-LS1-6)

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

PS3.D: Energy in Chemical Processes and Everyday Life

Energy and Matter

English Language Arts

Mathematics

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content.

Career Readiness Practices

.

CRP2. Apply appropriate academic and technical skills.

CRP4. Communicate clearly and effectively and with reason.

CRP6. Demonstrate creativity and innovation.  

CRP8. Utilize critical thinking to make sense of problems.

CRP11. Use technology to enhance productivity.


Unit  8 Summary:  Earth Systems

If no one was there, how do we know the Earth’s history?

What provides the forces that drive Earth’s systems?

Students examine geoscience data in order to understand processes and events in Earth’s history. Important crosscutting concepts in this unit are scale, proportion, and quantity, stability and change, and patterns in relation to the different ways geologic processes operate over geologic time. An important aspect of the history of Earth is that geologic events and conditions have affected the evolution of life, but different life forms have also played important roles in altering Earth’s systems. Students understand how Earth’s geosystems operate by modeling the flow of energy and cycling of matter within and among different systems. Students investigate the controlling properties of important materials and construct explanations based on the analysis of real geoscience data. Students are expected to demonstrate proficiency in analyzing and interpreting data and constructing explanations. They are also expected to use these practices to demonstrate understanding of the core ideas.

Student Learning Objectives

Construct a scientific explanation based on evidence from rock strata for how the geologic time scale is used to organize Earth's 4.6-billion-year-old history. [Clarification Statement: Emphasis is on how analyses of rock formations and the fossils they contain are used to establish relative ages of major events in Earth’s history. Examples of Earth’s major events could range from being very recent (such as the last Ice Age or the earliest fossils of homo sapiens) to very old (such as the formation of Earth or the earliest evidence of life). Examples can include the formation of mountain chains and ocean basins, the evolution or extinction of particular living organisms, or significant volcanic eruptions.] [Assessment Boundary: Assessment does not include recalling the names of specific periods or epochs and events within them.] (MS-ESS1-4) (CRP2) (CRP4) (CRP7) (CRP11)

Develop a model to describe the cycling of Earth's materials and the flow of energy that drives this process. [Clarification Statement: Emphasis is on the processes of melting, crystallization, weathering, deformation, and sedimentation, which act together to form minerals and rocks through the cycling of Earth’s materials.] [Assessment Boundary: Assessment does not include the identification and naming of minerals.] (MS-ESS2-1) (CRP2) (CRP6) (CRP7)

Construct an explanation based on evidence for how geoscience processes have changed Earth's surface at varying time and spatial scales. [Clarification Statement: Emphasis is on how processes change Earth’s surface at time and spatial scales that can be large (such as slow plate motions or the uplift of large mountain ranges) or small (such as rapid landslides or microscopic geochemical reactions), and how many geoscience processes (such as earthquakes, volcanoes, and meteor impacts) usually behave gradually but are punctuated by catastrophic events. Examples of geoscience processes include surface weathering and deposition by the movements of water, ice, and wind. Emphasis is on geoscience processes that shape local geographic features, where appropriate.] (MS-ESS2-2) CRP2) (CRP4) (CRP7) (CRP11)

Analyze and interpret data on the distribution of fossils and rocks, continental shapes, and seafloor structures to provide evidence of the past plate motions. [Clarification Statement: Examples of data include similarities of rock and fossil types on different continents, the shapes of the continents (including continental shelves), and the locations of ocean structures (such as ridges, fracture zones, and trenches).]  [Assessment Boundary: Paleomagnetic anomalies in oceanic and continental crust are not assessed.] (MS-ESS2-3) (CRP8) (CRP11)

Quick Links

Unit Sequence p. 2

What it Looks Like in the Classroom p. 3 

Connecting with ELA/Literacy and Math p. 3

Modifications p. 4

Research on Learning p. 6

Prior Learning p. 5 

Connections to Other Courses p. 7

Sample Open Education Resources p. 8

Appendix A: NGSS and Foundations p. 9

                                       Unit Sequence

Part A: How do we know that the Earth is approximately 4.6-billion-year-old history?

Concepts

Formative Assessment

  • The geologic time scale is used to organize Earth’s 4.6-billion-year-old history.
  • Rock formations and the fossils they contain are used to establish relative ages of major events in Earth’s history.
  • The geologic time scale interpreted from rock strata provides a way to organize Earth’s history.
  • Analyses of rock strata and the fossil record provide only relative dates, not an absolute scale.
  • Time, space, and energy phenomena can be observed at various scales using models to study systems that are too large or too small.

Students who understand the concepts are able to:

  • Construct a scientific explanation based on valid and reliable evidence from rock strata obtained from sources (including the students’ own experiments).
  • Construct a scientific explanation based on rock strata and 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.        

                                       Unit Sequence

Part B: What drives the cycling of Earth’s materials?

Concepts

Formative Assessment

  • Energy drives the process that results in the cycling of Earth’s materials.
  • The processes of melting, crystallization, weathering, deformation, and sedimentation act together to form minerals and rocks through the cycling of Earth’s materials.
  • All Earth processes are the result of energy flowing and matter cycling within and among the planet’s systems.
  • Energy flowing and matter cycling within and among the planet’s systems derive from the sun and Earth’s hot interior.
  • Energy that flows and matter that cycles produce chemical and physical changes in Earth’s materials and living organisms.
  • Explanations of stability and change in Earth’s natural systems can be constructed by examining the changes over time and processes at different scales, including the atomic scale.

Students who understand the concepts are able to:

  • Develop a model to describe the cycling of Earth’s materials and the flow of energy that drives this process.

                                       Unit Sequence

Part C: Do all of the changes to Earth systems occur in similar time scales?

Concepts

Formative Assessment

  • Geoscience processes have changed Earth’s surface at varying time and spatial scales.
  • Processes change Earth’s surface at time and spatial scales that can be large or small; many geoscience processes usually behave gradually but are punctuated by catastrophic events.
  • Geoscience processes shape local geographic features.
  • The planet’s systems interact over scales that range from microscopic to global in size, and they operate over fractions of a second to billions of years.
  • Interactions among Earth’s systems have shaped Earth’s history and will determine its future.
  • Water’s movements—both on the land and underground—cause weathering and erosion, which change the land’s surface features and create underground formations.
  • Time, space, and energy phenomena within Earth’s systems can be observed at various scales using models to study systems that are too large or too small.

Students who understand the concepts are able to:

  • Construct a scientific explanation for how geoscience processes have changed Earth’s surface at varying time and spatial scales based on valid and reliable evidence obtained from sources (including the students’ own experiments).
  • Construct a scientific explanation for how geoscience processes have changed Earth’s surface at varying time and spatial scales based on 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.
  • Collect evidence about processes that change Earth’s surface at time and spatial scales that can be large (such as slow plate motions or the uplift of large mountain ranges).
  • Collect evidence about processes that change Earth’s surface at time and spatial scales that can be small (such as rapid landslides or microscopic geochemical reactions), and how many geoscience processes (such as earthquakes, volcanoes, and meteor impacts) usually behave gradually but are punctuated by catastrophic events.

                                       Unit Sequence

Part D: How is it possible for the same kind of fossils to be found in New Jersey and in Africa?

Concepts

Formative Assessment

  • Tectonic processes continually generate new sea floor at ridges and destroy old sea floor at trenches.
  • Maps of ancient land and water patterns, based on investigations of rocks and fossils, make clear how Earth’s plates have moved great distances, collided, and spread apart.
  • Patterns in rates of change and other numerical relationships can provide information about past plate motions.
  • The distribution of fossils and rocks, continental shapes, and sea floor structures to provide evidence of past plate motions.
  • Similarities of rock and fossil types on different continents, the shapes of the continents (including continental shelves), and the locations of ocean structures (such as ridges, fracture zones, and trenches) provide evidence of past plate motions.

Students who understand the concepts are able to:

  • • Analyze and interpret data such as distributions of fossils and rocks, continental shapes, and sea floor structures to provide evidence of past plate motions.
  • Analyze how science findings have been revised and/or reinterpreted based on new evidence about past plate motions.

What It Looks Like in the Classroom

Within this unit, students will use the geologic time scale to organize Earth’s 4.6-billion-year-old history. They will cite specific textual evidence from science and technical texts to support analysis of rock strata to show how the geologic time scale is used to organize Earth’s 4.6-billion-year-old history. They will use analysis of rock formations and the fossils they contain to establish relative ages of major events in Earth’s history. Examples of Earth’s major events could include the Ice Age or the earliest fossils of Homo sapiens, or the formation of Earth and the earliest evidence of life. Emphasis should be on analyses of rock strata providing only relative dates, not an absolute scale. Students can use variables to represent numbers or quantities and write expressions when solving problems while constructing their explanations. Examples can include the formation of mountain chains and ocean basins, the evolution or extinction of particular living organisms, or significant volcanic eruptions. [Note: Assessment does not include recalling the names of specific periods or epochs and events within them.]

Students will develop and use models to describe the cycling of Earth materials and the flow of energy that drives this process. This energy comes from the heat of the core of the Earth, which is transferred to the mantle. Convection currents within the mantle then drive the movement of tectonic plates. Emphasis is on the processes of melting, crystallization, weathering, deformation, and sedimentation, which act together to form minerals and rocks through the cycling of Earth’s materials. Students can generate models to demonstrate the rock cycle, with specific focus on the processes causing change. Students can analyze pictures and rock samples that demonstrate various processes of melting, crystallization, weathering, deformation, and sedimentation. [Note: Students are not identifying and naming minerals within this unit].

Students will construct an explanation based on evidence for how geoscience processes have changed Earth’s surface at varying time and spatial scales. Emphasis is on how processes change Earth’s surface at time and spatial scales that can be large (such as slow plate motions or the uplift of large mountain ranges) or small (such as rapid landslides or microscopic geochemical reactions). Further emphasis is on how many geoscience processes (such as earthquakes, volcanoes, and meteor impacts) usually behave gradually but are punctuated by catastrophic events. Students can gather data and plot volcanoes and earthquakes in order to collect evidence to support the idea that these interactions among Earth’s systems have shaped Earth’s history and will determine its future. Additional examples can include changes on Earth’s surface from weathering and deposition by the movements of water, ice, and wind. Emphasis is also on geoscience processes that shape local geographic features, such as New Jersey’s Ridge and Valley Province, Highlands, Piedmont, and Coastal Plain.

Students convey ideas, concepts, and information through the selection, organization, and analysis of relevant content, and they may use multimedia components and visual displays. Students can also compare and contrast the information gained from experiments, simulations, video, or multimedia sources showing evidence of past plate motion with that gained by reading a text on the same topic. They use informative/explanatory texts to examine evidence for how geoscience processes have changed and reason abstractly and quantitatively when analyzing this evidence. They may integrate quantitative or technical information expressed in a flowchart, diagram, model, graph, or table. They can also use variables to represent numbers or quantities and write expressions when solving problems while constructing their explanations.

Students will analyze and interpret data on the distribution of fossils and rocks, and they will look at the continental shapes and sea floor structures to provide evidence of past plate motions. Maps of ancient land and water patterns, based on investigations of rocks and fossils, make clear how Earth’s plates have moved great distances, collided, and spread apart. Tectonic processes continually generate new ocean sea floor at ridges and destroy old sea floor at trenches. Examples of the data include similarities of rock and fossil types on different continents, the shapes of the continents (including continental shelves), and the locations of ocean structures (such as ridges, fracture zones, and trenches). Students may use numerical relationships, symbols, and words while analyzing patterns in rates of change on Earth’s crust. Students can use variables to represent numerical data and write expressions or construct simple equations and inequalities when solving a problems involved in the analysis of data about past plate motions. Applying interpreted data on the distribution of fossils and rocks, continental shapes, and sea floor structures, students can provide evidence of past plate motions. [Note: Students are not analyzing paleomagnetic anomalies in oceanic and continental crust in this unit].

Connecting with English Language Arts/Literacy and Mathematics

English Language Arts

  • Cite specific textual evidence based on evidence from rock strata for how the geologic time scale is used to organize Earth’s 4.6-billion-year-old history to support analysis of science and technical texts.
  • Write informative/explanatory texts to examine evidence from rock strata for how the geologic time scale is used to organize Earth’s 4.6 billion-year-old history and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content.
  • Cite specific textual evidence for how geoscience processes have changed Earth’s surface at varying time and spatial scales to support analysis of science and technical texts.
  • Use informative/explanatory texts to examine evidence for how geoscience processes have changed Earth’s surface at varying time and spatial scales and convey ideas, concepts, and information through the selection, organization, and analysis of relevant content.
  • Include multimedia components and visual displays in presentations about evidence for how geoscience processes have changed Earth’s surface at varying time and spatial scales to clarify claims and findings and emphasize salient points.
  • Cite specific textual evidence of past plate motion to support analysis of science texts.
  • Integrate quantitative or technical information about evidence of past plate motions expressed in words in a text with a version of that information expressed in a flowchart, diagram, model, graph, or table.
  • Compare and contrast the information gained from experiments, simulations, video, or multimedia sources showing evidence of past plate motion with that gained from reading a text on the same topic.

Mathematics

  • Use variables to represent numbers and write expressions when solving problems while constructing explanations from evidence from rock strata for how the geologic time scale is used to organize Earth’s 4.6-billion-year-old history; understand that a variable can represent an unknown number or, depending on the purpose at hand, any number in a specific set.
  • Use variables to represent quantities in a real-world or mathematical problem when solving problems while constructing explanations from evidence from rock strata for how the geologic time scale is used to organize Earth’s 4.6-billion-year-old history, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
  • Reason abstractly and quantitatively when analyzing evidence for how geoscience processes have changed Earth’s surface at varying time and spatial scales.
  • Use variables to represent numbers and write expressions when solving a real-world or mathematical problem involving evidence for how geoscience processes have changed Earth’s surface at varying time and spatial scales. Understand that a variable can represent an unknown number or, depending on the purpose at hand, any number in a specified set.
  • Use variables to represent quantities in a real-world or mathematical problem involving evidence for how geoscience processes have changed Earth’s surface at varying time and spatial scales, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
  • Use numbers, symbols, and words while analyzing and interpreting data on the distribution of fossils and rocks, continental shapes, and sea floor structures to provide evidence of past plate motions.
  • Use variables to represent numerical data and write expressions when solving a problems involved in the analysis of data about past plate motions. Understand that a variable can represent an unknown number or, depending on the purpose at hand, any number in a specified set.
  • Use variables to represent quantities when analyzing data about past plate motions and construct simple equations and inequalities to solve problems by reasoning about the quantities.

Modifications

(Note: Teachers identify the modifications that they will use in the unit. See NGSS Appendix D: All Standards, All Students/Case Studies for vignettes and explanations of the modifications.)

  • Restructure lesson using UDL principals (http://www.cast.org/our-work/about-udl.html#.VXmoXcfD_UA)  
  • Structure lessons around questions that are authentic, relate to students’ interests, social/family background and knowledge of their community.
  • Provide students with multiple choices for how they can represent their understandings (e.g. multisensory techniques-auditory/visual aids; pictures, illustrations, graphs, charts, data tables, multimedia, modeling).  
  • Provide opportunities for students to connect with people of similar backgrounds (e.g. conversations via digital tool such as SKYPE, experts from the community helping with a project, journal articles, and biographies).
  • Provide multiple grouping opportunities for students to share their ideas and to encourage work among various backgrounds and cultures (e.g. multiple representation and multimodal experiences).
  • Engage students with a variety of Science and Engineering practices to provide students with multiple entry points and multiple ways to demonstrate their understandings.
  • Use project-based science learning to connect science with observable phenomena.
  • Structure the learning around explaining or solving a social or community-based issue.
  • Provide ELL students with multiple literacy strategies.
  • Collaborate with after-school programs or clubs to extend learning opportunities.

Research on Student Learning

Students of all ages may hold the view that the world was always as it is now, or that any changes that have occurred must have been sudden and comprehensive. The students in these studies did not, however, have any formal instruction on the topics investigated. Moreover, middle-school students taught by traditional means are not able to construct coherent explanations about the causes of volcanoes and earthquakes.

Few middle- and high-school students understand the molecular basis of heat conduction even after instruction. For example, students attribute to particles properties such as "hotness" and "coldness" or believe that heat is produced by particles rubbing against each other.

During instruction, upper elementary-school students use ideas that give heat an active drive or intent to explain observations of convection currents. They also draw parallels between evaporation and the water cycle and convection, sometimes explicitly explaining the upwards motion of convection currents as evaporation.

Students rarely think energy is measurable and quantifiable. Students' alternative conceptualizations of energy influence their interpretations of textbook representations of energy.

Middle- and high-school students tend to think that energy transformations involve only one form of energy at a time. Although they develop some skill in identifying different forms of energy, in most cases their descriptions of energy-change focus only on forms which have perceivable effects. The transformation of motion to heat seems to be difficult for students to accept, especially in cases with no temperature increase. Finally, it may not be clear to students that some forms of energy, such as light, sound, and chemical energy, can be used to make things happen.

The idea of energy conservation seems counterintuitive to middle- and high-school students who hold on to the everyday use of the term energy, but teaching heat dissipation ideas at the same time as energy conservation ideas may help alleviate this difficulty. Even after instruction, however, students do not seem to appreciate that energy conservation is a useful way to explain phenomena. A key difficulty students have in understanding conservation appears to derive from not considering the appropriate system and environment. In addition, middle- and high-school students tend to use their conceptualizations of energy to interpret energy conservation ideas. For example, some students interpret the idea that "energy is not created or destroyed" to mean that energy is stored up in the system and can even be released again in its original form. Or, students may believe that no energy remains at the end of a process, but may say that "energy is not lost" because an effect was caused during the process (for example, a weight was lifted). [17] Although teaching approaches which accommodate students' difficulties about energy appear to be more successful than traditional science instruction, the main deficiencies outlined above remain despite these approaches (NSDL, 2015).

Prior Learning

By the end of Grade 5, students understand that:

  • Some kinds of plants and animals that once lived on Earth are no longer found anywhere.
  • Fossils provide evidence about the types of organisms that lived long ago and also about the nature of their environments.
  • For any particular environment, some kinds of organisms survive well, some survive less well, and some cannot survive at all.
  • A variety of natural hazards result from natural processes.
  • Humans cannot eliminate natural hazards but can take steps to reduce their impacts.
  • Local, regional, and global patterns of rock formations reveal changes over time due to earth forces, such as earthquakes.
  • The presence and location of certain fossil types indicate the order in which rock layers were formed.
  • Water, ice, wind, living organisms, and gravity break rocks, soils, and sediments into smaller particles and move them around.
  • The locations of mountain ranges, deep ocean trenches, ocean floor structures, earthquakes, and volcanoes occur in patterns.
  • Most earthquakes and volcanoes occur in bands that are often along the boundaries between continents and oceans.
  • Major mountain chains form inside continents or near their edges. Maps can help locate the different land and water features of Earth.
  • Living things affect the physical characteristics of their regions.
  • A variety of hazards result from natural processes (e.g., earthquakes, tsunamis, volcanic eruptions).
  • Humans cannot eliminate the hazards but can take steps to reduce their impacts.

Future Learning

Physical science

  • Nuclear processes, including fusion, fission, and radioactive decays of unstable nuclei, involve release or absorption of energy.
  • The total number of neutrons plus protons does not change in any nuclear process.
  • Although energy cannot be destroyed, it can be converted to less useful forms—for example, to thermal energy in the surrounding environment.

Life science

  • Photosynthesis and cellular respiration (including anaerobic processes) provide most of the energy for life processes.
  • Plants or algae form the lowest level of the food web. At each link upward in a food web, only a small fraction of the matter consumed at the lower level is transferred upward to produce growth and release energy in cellular respiration at the higher level. Given this inefficiency, there are generally fewer organisms at higher levels of a food web.
  • Some matter reacts to release energy for life functions, some matter is stored in newly made structures, and much is discarded.
  • The chemical elements that make up the molecules of organisms pass through food webs and into and out of the atmosphere and soil, and they are combined and recombined in different ways.
  • At each link in an ecosystem, matter and energy are conserved.
  • Photosynthesis and cellular respiration are important components of the carbon cycle, in which carbon is exchanged among the biosphere, atmosphere, oceans, and geosphere through chemical, physical, geological, and biological processes.
  • Genetic information provides evidence of evolution. DNA sequences vary among species, but there are many overlaps; in fact, the ongoing branching that produces multiple lines of descent can be inferred by comparing the DNA sequences of different organisms. Such information is also derivable from the similarities and differences in amino acid sequences and from anatomical and embryological evidence.
  • Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment.
  • Natural selection leads to adaptation—that is, to a population dominated by organisms that are anatomically, behaviorally, and physiologically well suited to survive and reproduce in a specific environment. That is, the differential survival and reproduction of organisms in a population that have an advantageous heritable trait lead to an increase in the proportion of individuals in future generations that have the trait and to a decrease in the proportion of individuals that do not.
  • Adaptation also means that the distribution of traits in a population can change when conditions change.
  • Changes in the physical environment, whether naturally occurring or human induced, have thus contributed to the expansion of some species, the emergence of new distinct species as populations diverge under different conditions, and the decline—and sometimes the extinction—of some species.

Earth and space science

  • Continental rocks, which can be older than 4 billion years, are generally much older than the rocks of the ocean floor, which are less than 200 million years old.
  • Although active geologic processes, such as plate tectonics and erosion, have destroyed or altered most of the very early rock record on Earth, other objects in the solar system, such as lunar rocks, asteroids, and meteorites, have changed little over billions of years.
  • Studying these objects can provide information about Earth’s formation and early history.
  • Earth’s systems, being dynamic and interacting, cause feedback effects that can increase or decrease the original changes.
  • Evidence from deep probes and seismic waves, reconstructions of historical changes in Earth’s surface and its magnetic field, and an understanding of physical and chemical processes lead to a model of Earth with a hot but solid inner core, a liquid outer core, a solid mantle and crust. Motions of the mantle and its plates occur primarily through thermal convection, which involves the cycling of matter due to the outward flow of energy from Earth’s interior and gravitational movement of denser materials toward the interior.
  • The geological record shows that changes to global and regional climate can be caused by interactions among changes in the sun’s energy output or Earth’s orbit, tectonic events, ocean circulation, volcanic activity, glaciers, vegetation, and human activities.
  • These changes can occur on a variety of time scales from sudden (e.g., volcanic ash clouds) to intermediate (ice ages) to very long-term tectonic cycles.
  • The radioactive decay of unstable isotopes continually generates new energy within Earth’s crust and mantle, providing the primary source of the heat that drives mantle convection.
  • Plate tectonics can be viewed as the surface expression of mantle convection.
  • Plate tectonics is the unifying theory that explains the past and current movements of the rocks at Earth’s surface and provides a framework for understanding its geologic history.
  • Plate movements are responsible for most continental and ocean floor features and for the distribution of most rocks and minerals within Earth’s crust.
  • The abundance of liquid water on Earth’s surface and its unique combination of physical and chemical properties are central to the planet’s dynamics. These properties include water’s exceptional capacity to absorb, store, and release large amounts of energy, transmit sunlight, expand upon freezing, dissolve and transport materials, and lower the viscosities and melting points of rocks.
  • The foundation for Earth’s global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, ocean, and land systems, and this energy’s re-radiation into space.
  • Gradual atmospheric changes were due to plants and other organisms that captured carbon dioxide and released oxygen.
  • Changes in the atmosphere due to human activity have increased carbon dioxide concentrations and thus affect climate.

Connections to Other Units

Grade 7 Unit 1: Structure and Properties of Matter

  • Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.
  • Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it.
  • Solids may be formed from molecules, or they may be extended structures with repeating subunits (e.g., crystals).

Grade 7 Unit 2: Interactions of Matter

  • Gases and liquids are made of molecules or inert atoms that are moving about relative to each other.
  • In a liquid, the molecules are constantly in contact with others; in a gas, they are widely spaced except when they happen to collide. In a solid, atoms are closely spaced and may vibrate in position but do not change relative locations.
  • The changes of state that occur with variations in temperature or pressure can be described and predicted using these models of matter.
  • Substances react chemically in characteristic ways. In a chemical process, the atoms that make up the original substances are regrouped into different molecules, and these new substances have different properties from those of the reactants.

Grade 7 Unit 3: Chemical Reactions

  • The total number of each type of atom is conserved, and thus the mass does not change.
  • Some chemical reactions release energy, others store energy.

Grade 8 Unit 4: Human Impacts on Earth Systems and Global Climate Change

  • Human activities have significantly altered the biosphere, sometimes damaging or destroying natural habitats and causing the extinction of other species. But changes to Earth’s environments can have different impacts (negative and positive) for different living things.
  • Typically as human populations and per-capita consumption of natural resources increase, so do the negative impacts on Earth unless the activities and technologies involved are engineered otherwise.  

Grade 8 Unit 5: Relationships among Forms of Energy

  • A system of objects may also contain stored (potential) energy, depending on their relative positions.
  • Energy is spontaneously transferred out of hotter regions or objects and into colder ones.

 Grade 7 Unit 8: Earth Systems

  • All Earth processes are the result of energy flowing and matter cycling within and among the planet’s systems. This energy is derived from the sun and Earth’s hot interior. The energy that flows and matter that cycles produce chemical and physical changes in Earth’s materials and living organisms.
  • The planet’s systems interact over scales that range from microscopic to global in size, and they operate over fractions of a second to billions of years. These interactions have shaped Earth’s history and will determine its future.


Appendix A: NGSS and Foundations for the Unit

Construct a scientific explanation based on evidence from rock strata for how the geologic time scale is used to organize Earth's 4.6-billion-year-old history. [Clarification Statement: Emphasis is on how analyses of rock formations and the fossils they contain are used to establish relative ages of major events in Earth’s history. Examples of Earth’s major events could range from being very recent (such as the last Ice Age or the earliest fossils of homo sapiens) to very old (such as the formation of Earth or the earliest evidence of life). Examples can include the formation of mountain chains and ocean basins, the evolution or extinction of particular living organisms, or significant volcanic eruptions.] [Assessment Boundary: Assessment does not include recalling the names of specific periods or epochs and events within them.] (MS-ESS1-4)

Develop a model to describe the cycling of Earth's materials and the flow of energy that drives this process. [Clarification Statement: Emphasis is on the processes of melting, crystallization, weathering, deformation, and sedimentation, which act together to form minerals and rocks through the cycling of Earth’s materials.] [Assessment Boundary: Assessment does not include the identification and naming of minerals.] (MS-ESS2-1)

Construct an explanation based on evidence for how geoscience processes have changed Earth's surface at varying time and spatial scales. [Clarification Statement: Emphasis is on how processes change Earth’s surface at time and spatial scales that can be large (such as slow plate motions or the uplift of large mountain ranges) or small (such as rapid landslides or microscopic geochemical reactions), and how many geoscience processes (such as earthquakes, volcanoes, and meteor impacts) usually behave gradually but are punctuated by catastrophic events. Examples of geoscience processes include surface weathering and deposition by the movements of water, ice, and wind. Emphasis is on geoscience processes that shape local geographic features, where appropriate.] (MS-ESS2-2)

Analyze and interpret data on the distribution of fossils and rocks, continental shapes, and seafloor structures to provide evidence of the past plate motions. [Clarification Statement: Examples of data include similarities of rock and fossil types on different continents, the shapes of the continents (including continental shelves), and the locations of ocean structures (such as ridges, fracture zones, and trenches).]  [Assessment Boundary: Paleomagnetic anomalies in oceanic and continental crust are not assessed.] (MS-ESS2-3)

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Disciplinary Core Ideas

Crosscutting Concepts

Developing and Using Models

Constructing Explanations and Designing Solutions

Analyzing and Interpreting Data

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

         Connections to Nature of Science

Scientific Knowledge is Open to Revision in Light of New Evidence

  • Science findings are frequently revised and/or reinterpreted based on new evidence. (MS-ESS2-3)

ESS1.C: The History of Planet Earth

ESS2.A: Earth’s Materials and Systems

ESS2.B: Plate Tectonics and Large-Scale System Interactions

Stability and Change

Scale Proportion and Quantity

Patterns

English Language Arts

Mathematics

Technology Standards

8.1.8.A.1  Demonstrate knowledge of real world problems using digital tools.

8.1.8.A.3  Use and/or  develop simulations that provides and environment to solve a problem.

8.1.8.A.4  Graph and calculate data within a spreadsheet and present a summary of the results.

8.1.8.D.1  Model appropriate online behaviors related to cyber safety

including appropriate use of social media.

8.1.8.D.4  Asses the credibility and accuracy of digital content.

Career Readiness Practices

CRP2. Apply appropriate academic and technical skills.

CRP4. Communicate clearly and effectively and with reason.

CRP6. Demonstrate creativity and innovation.

CRP7. Employ valid and reliable research strategies.

CRP8. Utilize critical thinking to make sense of problems.

CRP11. Use technology to enhance productivity.

BOE  adopted Spring 2016