Biology Standards.

1. (1) From Molecules to Organisms: Structures and Processes.
2. (A) Performance expectation 1. Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential functions of life through systems of specialized cells.
3. (i) Clarification Statement. Emphasis is on the conceptual understanding that the sequence of nucleotides in DNA determines the amino acid sequence of proteins through the process of transcription and translation.
4. (ii) Assessment Boundary. Assessment does not include identification of specific cell or tissue types, whole body systems, specific protein structures and functions, or the biochemistry of protein synthesis.
5. (iii) Science and Engineering Practices. Constructing Explanations. Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) 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.
6. (iv) Disciplinary Core Ideas. Structure and Function.
7. (I) Systems of specialized cells within organisms help them perform the essential functions of life.
8. (II) All cells contain genetic information in the form of DNA molecules.
9. (III) 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 the cells.
10. (v) Crosscutting Concepts. Structure and Function. The functions and properties of natural and designed objects and systems can be inferred from their overall structure, the way their components are shaped and used, and the molecular substructures of their various materials.
11. (B) Performance expectation 2. Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions withinmulticellular organisms.
12. (i) Clarification Statement. Emphasis is on developing a model in which relevant parts (e.g., an organ system, organs, and their component tissues) and processes (e.g., transport of fluids, motion) of body systems in multicellular organisms are identified and described. Models should then be used to illustrate how relevant parts within a system interact and how systems interact with one another to provide specific functions in multicellular organisms.
13. (ii) Assessment Boundary. Assessment does not include interactions and functions at the molecular or chemical reaction level and is limited to two systems interacting at a time.
14. (iii) Science and Engineering Practices. Developing and Using Models. Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system.
15. (iv) Disciplinary Core Ideas. Structure and Function. 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.
16. (v) Crosscutting Concepts. Systems and System Models. Models (e.g., physical, mathematical, computer) can be used to simulate systems and interactions, including energy, matter, and information flow within and between systems at different scales.
17. (C) Performance expectation 3. Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis in living organisms.
18. (i) Clarification Statement. A state of homeostasis (stability) must be maintained for organisms to remain alive and functional even as external conditions change within some range. Examples of investigations could include heart rate response to exercise, stomata response to moisture and temperature, root development in response to water levels, and cell response to hypertonic and hypotonic environments. Feedback mechanisms could include the promotion of a stimulus through positive feedback and the inhibition of a stimulus through negative feedback.
19. (ii) Assessment Boundary. Assessment does not include the cellular processes involved in the feedback mechanism.
20. (iii) Science and Engineering Practices. Planning and Conducting Investigations. Plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence.
21. (iv) Disciplinary Core Ideas. Structure and Function.
22. (I) Feedback mechanisms maintain a living system’s internal conditions within certain limits and mediate behaviors, allowing it to remain alive and functional even as external conditions change within some range. Outside that range (e.g., at too high or low external temperature, with too little food or water available) the organism cannot survive.
23. (II) Feedback mechanisms can encourage (through positive feedback) or discourage (negative feedback) what is going on inside the living system.
24. (v) Crosscutting Concepts. Stability and Change. Feedback (negative or positive) can stabilize or destabilize a system.
25. (vi) Connections to Scientific Literacy. Scientific Investigations Use a Variety of Methods. Scientific inquiry is characterized by a common set of values that include: logical thinking, precision, open-mindedness, objectivity, skepticism, replicability of results, and honest and ethical reporting of findings.
26. (D) Performance expectation 4. Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.
27. (i) Clarification Statement. Emphasis is not on the details of each phase of mitosis but on the conceptual understanding that mitosis produces genetically identical cells via DNA replication and cell division and that immature cells may become specialized through differentiation.
28. (ii) Assessment Boundary. Assessment does not include specific gene control mechanisms or rote memorization of the steps of mitosis.
29. (iii) Science and Engineering Practices. Developing and Using Models. Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system.
30. (iv) Disciplinary Core Ideas. Growth and Development of Organisms.
31. (I) In multicellular organisms, individual cells grow and then divide via a process called mitosis, thereby allowing the organism to grow.
32. (II) 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.
33. (III) 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.
34. (v) Crosscutting Concepts. Systems and System Models. Models (e.g., physical, mathematical, computer) can be used to simulate systems and interactions, including energy, matter, and information flow within and between systems at different scales.
35. (E) Performance expectation 5. Use a model to illustrate how photosynthesis transforms light energy into stored chemical energy.
36. (i) Clarification Statement. Emphasis is on illustrating inputs and outputs of matter and the transfer and transformation of energy in photosynthesis by plants and other photosynthesizing organisms. Examples of models could include diagrams, chemical equations, or conceptual models developed from investigations.
37. (ii) Assessment Boundary. The assessment should provide evidence of students’ abilities to describe the inputs and outputs of photosynthesis, not the specific biochemical steps (e.g., photosystems, electron transport, and Calvin Cycle).
38. (iii) Science and Engineering Practices. Developing and Using Models. Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system.
39. (iv) Disciplinary Core Ideas. Organization for Matter and Energy Flow in Organisms. The process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.
40. (v) Crosscutting Concepts. Energy and Matter. Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.
41. (F) Performance expectation 6. Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.
42. (i) Clarification Statement. Emphasis is on using evidence from models and/or simulations to support explanations for how organisms take in matter and rearrange the atoms to form amino acids and/or other large carbon-based molecules. Organic macromolecules could include proteins, carbohydrates (polysaccharides), nucleic acids, and lipids. Monomers could include amino acids, mono- and disaccharides, nucleotides, and fatty acids.
43. (ii) Assessment Boundary. Assessment does not include the details of the specific chemical reactions or identification of macromolecules.
44. (iii) Science and Engineering Practices. Constructing Explanations. Use evidence (e.g., measurements, observations, patterns) to construct or support an explanation.
45. (iv) Disciplinary Core Ideas. Organization for Matter and Energy Flow in Organisms.
46. (I) 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 large molecules (such as proteins or DNA), used, for example, to form new cells.
47. (II) As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.
48. (v) Crosscutting Concepts. Energy and Matter. Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.
49. (G) Performance expectation 7. Use a model to illustrate that cellular respiration is a chemical process whereby the bonds of food molecules and oxygen molecules are broken and the bonds in new compounds are formed, resulting in a net transfer of energy.
50. (i) Clarification Statement. Emphasis is on illustrating the conceptual understanding of the inputs and outputs of the process of cellular respiration, including energy transfer. Models could include diagrams and chemical equations.
51. (ii) Assessment Boundary. Assessment should not include identification of the steps or specific processes involved in cellular respiration (e.g. glycolysis, Kreb’s Cycle, and electron transport).
52. (iii) Science and Engineering Practices. Developing and Using Models. Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system.
53. (iv) Disciplinary Core Ideas. Organization for Matter and Energy Flow in Organisms.
54. (I) As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.
55. (II) As a result of these chemical reactions, energy is transferred from one system of interacting molecules to another.
56. (III) Cellular respiration is a chemical process in which the bonds of food molecules and oxygen molecules are broken and new compounds are formed that can transport energy to muscles.
57. (IV) Cellular respiration also releases the energy needed to maintain body temperature despite ongoing energy transfer to the surrounding environment.
58. (v) Crosscutting Concepts. Energy and Matter. Energy cannot be created or destroyed. It only moves between one place to another, between objects and/or fields, or between systems.
59. (2) Ecosystems: Interactions, Energy, and Dynamics.
60. (A) Performance expectation 1. Use mathematical and/or computational representations to support explanations of factors that affect carrying capacities of ecosystems at different scales.
61. (i) Clarification Statement. Emphasis is on quantitative analysis and comparison of the relationships among interdependent factors including boundaries, resources, climate, and competition. Examples of mathematical comparisons could include graphs, charts, histograms, or population changes gathered from simulations or historical data sets.
62. (ii) Assessment Boundary. Assessment does not include deriving mathematical equations to make comparisons.
63. (iii) Science and Engineering Practices. Using Mathematics and Computational Thinking. Use mathematical, computational, and/or algorithmic representations of phenomena to describe and/or support claims and/or explanations.
64. (iv) Disciplinary Core Ideas. Interdependent Relationships in Ecosystems.
65. (I) Ecosystems have carrying capacities, which are limits to the number 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 as predation, competition, and disease.
66. (II) 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.
67. (v) Crosscutting Concepts. Scale, Proportion, and Quantity. The significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs.
68. (B) Performance expectation 2. Use mathematical representations as evidence to support and revise explanations about factors affecting biodiversity and populations in ecosystems.
69. (i) Clarification Statement. Emphasis is on using mathematical representations to describe factors that affect biodiversity and ecosystems, such as carrying capacity and its impact on population dynamics. Examples of mathematical representations could include finding the average, determining trends, and using graphical comparisons of multiple sets of data.
70. (ii) Assessment Boundary. Assessment is limited to provided data.
71. (iii) Science and Engineering Practices. Using Mathematics and Computational Thinking. Use mathematical representation to describe and/or support scientific conclusions.
72. (iv) Disciplinary Core Ideas.
73. (I) Interdependent Relationships in Ecosystems.

a. Ecosystems have carrying capacities, which are limits to the number of organisms and populations they can support. These limits result from such factors as the availability of living (biotic) and nonliving (abiotic) resources and from such challenges such as predation, competition, and disease.

b. 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.

1. (II) Ecosystem Dynamics, Functioning, and Resilience

a. A complex set of interactions within an ecosystem can keep its number and types of organisms relatively constant over long periods of time under stable conditions.

b. If a modest biological or physical disturbance to an ecosystem occurs, it may return to its more or less original status (i.e., the ecosystem is resilient) as opposed to becoming a very different ecosystem.

c. Extreme fluctuations in conditions or the size of any populations, however, can challenge the functions of ecosystems in terms of resources and habitat availability.

1. (v) Crosscutting Concepts. Scale, Proportion, and Quantity. Algebraic thinking is used to examine scientific data and predict the effect of a change in one variable on another (e.g., linear growth vs. exponential growth).
2. (vi) Connections to Scientific Literacy. Scientific Knowledge is Open to Revision in Light of New Evidence. Most scientific knowledge is quite durable, but is, in principle, subject to change based on new evidence and/or reinterpretation of existing evidence.
3. (C) Performance expectation 3. Construct and revise an explanation based on evidence for the cycling of matter and the flow of energy in aerobic and anaerobic conditions.
4. (i) Clarification Statement. Emphasis is on describing the role of aerobic and anaerobic respiration in the conservation of matter and flow of energy into, out of, and within various ecosystems (e.g., chemosynthetic bacteria near deep ocean vents, yeast in various environments, muscle cells during exertion, water-logged plants).
5. (ii) Assessment Boundary. Assessment focuses on the conceptual understanding and does not include the specific chemical processes of either aerobic or anaerobic respiration.
6. (iii) Science and Engineering Practices. Constructing Explanations. Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) 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.
7. (iv) Disciplinary Core Ideas. Cycles of Matter and Energy Transfer in Ecosystems. Photosynthesis and cellular respiration (including anaerobic processes) provide most of the energy for life processes.
8. (v) Crosscutting Concepts. Energy and Matter. Energy drives the cycling of matter within and between systems.
9. (vi) Connections to Scientific Literacy. Scientific Knowledge is Open to Revision in Light of New Evidence. Most scientific knowledge is quite durable, but is, in principle, subject to change based on new evidence and/or reinterpretation of existing evidence.
10. (D) Performance expectation 4. Use a mathematical representation to support claims for the cycling of matter and the flow of energy among organisms in an ecosystem.
11. (i) Clarification Statement. Emphasis is on using a mathematical model of stored energy in biomass to describe the transfer of energy from one trophic level to another and that matter and energy are conserved as matter cycles and energy flows through ecosystems. Emphasis is on atoms and molecules such as carbon, oxygen, hydrogen, and nitrogen being conserved as they move through an ecosystem.
12. (ii) Assessment Boundary. The assessment should provide evidence of students’ abilities to develop and use energy pyramids, food chains, food webs, and other models from data sets.
13. (iii) Science and Engineering Practices. Using Mathematics and Computational Thinking. Use mathematical representation to describe and/or support scientific conclusions.
14. (iv) Disciplinary Core Ideas. Cycles of Matter and Energy Transfer in Ecosystems.
15. (I) Plants or algae form the lowest level of the food web.
16. (II) 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.
17. (III) Given this inefficiency, there are generally fewer organisms at higher levels of a food web.
18. (IV) Some matter reacts to release energy for life functions, some matter is stored in newly made structures, and much is discarded.
19. (V) 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.
20. (VI) At each link in an ecosystem, matter and energy are conserved.
21. (v) Crosscutting Concepts. Energy and MatterEnergy cannot be created or destroyed. It only moves between one place to another, between objects and/or fields, or between systems.
22. (E) Performance expectation 5. Develop a model to illustrate the role of photosynthesis and cellular respiration in the cycling of carbon among the biosphere, atmosphere, hydrosphere, and geosphere.
23. (i) Clarification Statement. Examples of models could include diagrams, simulations, and mathematical models. The emphasis is on the movement of carbon.
24. (ii) Assessment Boundary. Assessment does not include the specific chemical steps of photosynthesis and respiration.
25. (iii) Science and Engineering Practices. Developing and Using Models. Develop a model based on evidence to illustrate the relationships between systems or components of a system.
26. (iv) Disciplinary Core Ideas.
27. (I) Cycles of Matter and Energy Transfer in Ecosystems. 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.
28. (II) Energy in Chemical Processes. The main way that solar energy is captured and stored on Earth is through the complex chemical process known as photosynthesis.
29. (v) Crosscutting Concepts. Systems and System Models. Models (e.g., physical, mathematical, computer) can be used to simulate systems and interactions; including energy, matter, and information flow within and between systems at different scales.
30. (F) Performance expectation 6. Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.
31. (i) Clarification Statement. Examples of changes in ecosystem conditions could include modest biological or physical changes, such as moderate hunting or a seasonal flood; and extreme changes, such as volcanic eruption or sea level rise.
32. (ii) Assessment Boundary. The assessment should provide evidence of students’ abilities to derive trends from graphical representations of population trends. Assessments should focus on describing drivers of ecosystem stability and change, not on the organismal mechanisms of responses and interactions.
33. (iii) Science and Engineering Practices. Engaging in Argument from Evidence. Evaluate the claims, evidence, and/or reasoning behind currently accepted explanations or solutions to determine the merit of arguments.
34. (iv) Disciplinary Core Ideas. Ecosystem Dynamics, Functioning, and Resilience.
35. (I) A complex set of interactions within an ecosystem can keep its number and types of organisms relatively constant over long periods of time under stable conditions.
36. (II) If a modest biological or physical disturbance to an ecosystem occurs, it may return to its more or less original status (i.e., the ecosystem is resilient) as opposed to becoming a very different ecosystem.
37. (III) Extreme fluctuations in conditions or the size of any populations, however, can challenge the functions of ecosystems in terms of resources and habitat availability.
38. (v) Crosscutting Concepts. Stability and Change. Much of science deals with constructing explanations of how things change and how they remain stable.
39. (vi) Connections to Scientific Literacy. Scientific Knowledge is Open to Revision in Light of New Evidence. Scientific argumentation is a mode of logical discourse used to clarify the strength of relationships between ideas and evidence that may result in revision of an explanation.
40. (G) Performance expectation 7. Evaluate evidence for the role of group behavior on individual and species’ chances to survive and reproduce.
41. (i) Clarification Statement. Emphasis is on analyzing evidence of the effects (both positive and negative) of grouping behaviors (e.g., flocking, schooling, herding) and cooperative behaviors (e.g., hunting, migrating, swarming) on survival and reproduction.
42. (ii) Assessment Boundary. The assessment should provide evidence of students’ abilities to: (1) distinguish between group versus individual behavior, (2) identify evidence supporting the outcomes of group behavior, and (3) develop logical and reasonable arguments based on evidence.
43. (iii) Science and Engineering Practices. Engaging in Argument from Evidence. Evaluate the claims, evidence, and/or reasoning behind currently accepted explanations or solutions to determine the merit of arguments.
44. (iv) Disciplinary Core Ideas. Social Interactions and Group Behavior.
45. (I) Group behavior has evolved because membership can increase the chances of survival for individuals and their genetic relatives.
46. (II) Some animals have a strong drive for social affiliation with members of their own species and will suffer, behaviorally as well as physiologically, if reared in isolation, even if all of their physical needs are met.
47. (v) Crosscutting Concepts. Cause and Effect. Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
48. (vi) Connections to Scientific Literacy. Scientific Knowledge is Open to Revision in Light of New Evidence. Scientific argumentation is a mode of logical discourse used to clarify the strength of relationships between ideas and evidence that may result in revision of an explanation.
49. (3) Heredity: Inheritance and Variation of Traits.
50. (A) Performance expectation 1. Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring.
51. (i) Clarification Statement. Emphasis is on the formulation of questions about how DNA and chromosomes function in the inheritance of traits, focusing on the relationship between DNA sequences, genes, proteins, and the resulting observable traits.
52. (ii) Assessment Boundary. Assessment does not include the phases of meiosis or the biochemical mechanism of specific steps in the process.
53. (iii) Science and Engineering Practices. Asking Questions. Ask questions that arise from examining models or a theory, to clarify and/or seek additional information and relationships.
54. (iv) Disciplinary Core Ideas.
55. (I) Structure and Function .

a. All cells contain genetic information in the form of DNA molecules.

b. 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 the cells.

1. (II) Inheritance of Traits.

a. Each chromosome consists of a single, very long DNA molecule, and each gene on the chromosome is a particular segment of that DNA.

b. 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.

c. Not all DNA codes for protein; some segments of DNA are involved in regulatory or structural functions, and some have no, as of yet, known functions.

1. (v) Crosscutting Concepts. Cause and Effect. Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
2. (B) Performance expectation 2. Make and defend a claim based on evidence that inheritable genetic variations may result from (1) new genetic combinations through meiosis, (2) viable error occurring during replication, and/or (3) mutations caused by environmental factors.
3. (i) Clarification Statement. Emphasis is on using data to support arguments for the way genetic variation occurs.
4. (ii) Assessment Boundary. Assessment does not include the phases of meiosis or the biochemical mechanisms of specific steps in the process.
5. (iii) Science and Engineering Practices. Engaging in Argument from Evidence. Make and defend a claim based on evidence about the natural world or the effectiveness of a design solution that reflects scientific knowledge and student-generated evidence.
6. (iv) Disciplinary Core Ideas. Variation of Traits.
7. (I) 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.
8. (II) Although DNA replication is tightly regulated and remarkably accurate, errors do occur and result in mutations, which also cause mutations in genes, and variables in mutations are also inherited.
9. (III) Environmental factors also affect expression of traits, and hence affect the probability of occurrences of traits in the population; thus, the variation and distribution of traits observed depends on both genetic and environmental factors.
10. (v) Crosscutting Concepts. Cause and Effect. Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
11. (C) Performance expectation 3. Apply concepts of statistics and probability to explain the variation and distribution of expressed traits in a population.
12. (i) Clarification Statement. Emphasis is on distribution and variation of traits in a population and the use of mathematics (e.g., calculations of frequencies based on data from Punnett squares, graphical representations, conceptual understanding of Hardy-Weinberg equilibrium) to describe the distribution of traits in a population, not individuals.
13. (ii) Assessment Boundary. Emphasis is on using evidence from data and/or simulations to explain population-level patterns of trait distribution. Assessment does not include Hardy-Weinberg calculations.
14. (iii) Science and Engineering Practices. Analyzing and Interpreting Data. Apply concepts of statistics and probability (including determining function fits to data, slope, intercept, and correlation coefficient for linear fits) to scientific questions and problems, using digital tools when feasible.
15. (iv) Disciplinary Core Ideas. Variation of Traits. Environmental factors also affect expression of traits, and hence affect the probability of occurrences of traits in the population; thus, the variation and distribution of traits observed depends on both genetic and environmental factors.
16. (v) Crosscutting Concepts. Scale, Proportion, and Quantity. Algebraic thinking is used to examine scientific data and predict the effect of a change in one variable on another (e.g., linear growth vs. exponential growth).
17. (4) Biological Unity and Diversity.
18. (A) Performance expectation 1. Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.
19. (i) Clarification Statement. Emphasis is on a conceptual understanding of the role each line of evidence has relating to common ancestry and biological evolution. Examples of evidence should include similarities in DNA and amino acid sequences, but could also include fossil record, anatomical structures, and the order of appearance of structures in embryological development.
20. (ii) Assessment Boundary. Emphasis is on students’ abilities to use evidence such as DNA and amino acid sequences, cladograms, analogous/homologous structures, and fossil records to communicate their understanding of common ancestry and biological evolution.
21. (iii) Science and Engineering Practices. Obtaining, Evaluating, and Communicating Information. Communicate scientific information (e.g., about phenomena) in multiple formats (including orally, graphically, textually, and mathematically).
22. (iv) Disciplinary Core Ideas.
23. (I) Evidence of Common Ancestry and Diversity. Genetic information provides evidence of common ancestry and diversity. 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.
24. (II) Adaptation. 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.
25. (v) Crosscutting Concepts. Patterns. Different patterns may be observed at each of the scales at which a system is studied and can provide evidence for causality in explanations of phenomena.
26. (vi) Connections to Scientific Literacy. Science Models, Laws, and Theories Explain Natural Phenomena. A scientific theory is a substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment, and the science community validates each theory before it is accepted. If new evidence is discovered that the theory does not accommodate, the theory is generally modified in light of this new evidence.
27. (B) Performance expectation 2. Construct an explanation based on evidence that biological diversity is influenced by (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.
28. (i) Clarification Statement. Emphasis is on using evidence to explain the influence each of the four factors has on the number of organisms, behaviors, morphology, or physiology in terms of ability to survive and reproduce. Examples of evidence could include mathematical models such as simple distribution graphs and comparisons that show how changes in one factor can impact another.
29. (ii) Assessment Boundary. Assessment does not include genetic drift, gene flow through migration, and co-evolution.
30. (iii) Science and Engineering Practices. Constructing Explanations. Construct an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) 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.
31. (iv) Disciplinary Core Ideas. Natural Selection. Natural selection occurs only if there is both (1) variation in the genetic information between organisms in a population and (2) variation in the expression of that genetic information—that is, trait variation— that leads to differences in performance among individuals.
32. (v) Crosscutting Concepts. Cause and Effect. Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
33. (C) Performance expectation 3. Apply concepts of statistics and probability to support explanations that organisms with an advantageous heritable trait tend to increase in proportion to organisms lacking this trait.
34. (i) Clarification Statement. Emphasis is on analyzing shifts in numerical distribution of traits and using these shifts as evidence to support explanations for adaptations.
35. (ii) Assessment Boundary. Emphasis is on students’ abilities to analyze shifts in numerical distribution of traits as evidence to support explanations. Analysis is limited to basic statistical and graphical analysis, not allele or gene frequency calculations.
36. (iii) Science and Engineering Practices. Analyzing and Interpreting Data. Apply concepts of statistics and probability (including determining function fits to data, slope, intercept, and correlation coefficient for linear fits) to scientific and engineering questions and problems, using digital tools when feasible.
37. (iv) Disciplinary Core Ideas.
38. (I) Natural Selection. Natural selection occurs only if there is both (1) variation in the genetic information between organisms in a population and (2) variation in the expression of that genetic information—that is, trait variation—that leads to differences in performance among individuals. The traits that positively affect survival are more likely to be reproduced, and thus are more common in the population.
39. (II) Adaptation. 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 leads 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.
40. (v) Crosscutting Concepts. Patterns. Different patterns may be observed at each of the scales at which a system is studied and can provide evidence for causality in explanations and phenomena.
41. (D) Performance expectation 4. Construct an explanation based on evidence for how natural selection leads to adaptation of populations.
42. (i) Clarification Statement. Emphasis is on using data to provide evidence for how specific biotic and abiotic differences in ecosystems (such as ranges of seasonal temperature, long-term climate change, acidity, light, geographic barriers, or adaptation of other organisms) contribute to a change in gene frequency over time, leading to adaptation of populations.
43. (ii) Science and Engineering Practices. Constructing Explanations. Construct an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) 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.
44. (iii) Disciplinary Core Ideas. Adaptation.
45. (I) 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.
46. (II) That is, the differential survival and reproduction of organisms in a population that have an advantageous heritable trait leads 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.
47. (III) 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.
48. (iv) Crosscutting Concepts. Cause and Effect. Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
49. (v) Connections to Scientific Literacy. Scientific Knowledge Assumes an Order and Consistency in Natural Systems. Scientific knowledge is based on the assumption that natural laws operate today as they did in the past and they will continue to do so in the future.
50. (E) Performance expectation 5. Evaluate the evidence supporting claims that changes in environmental conditions may result in (1) increases in the number of individuals of some species, (2) the emergence of new species over time, and (3) the extinction of other species.
51. (i) Clarification Statement. Emphasis is on determining cause and effect relationships for how changes to the environment such as deforestation, fishing, application of fertilizers, drought, flood, and the rate of change of the environment affect distribution or disappearance of traits in species.
52. (ii) Science and Engineering Practices. Engaging in Argument from Evidence. Evaluate the evidence behind currently accepted explanations or solutions to determine the merits of arguments.
53. (iii) Disciplinary Core Ideas. Adaptation.
54. (I) 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.
55. (II) Species become extinct because they can no longer survive and reproduce in their altered environment. If members cannot adjust to change that is too fast or drastic, the opportunity for the species’ adaptation over time is lost.
56. (iv) Crosscutting Concepts. Cause and Effect. Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.

Added at 20 Ok Reg 159, eff 10-10-02 (emergency)

Added at 20 Ok Reg 821, eff 5-15-03

Amended at 28 Ok Reg 2264, eff 7-25-11

Amended at 31 Ok Reg 1195, eff 9-12-14

Amended at 38 Ok Reg 1754, eff 9-11-21

Amended at 42 Ok Reg, Number 21, effective 7-26-25