Open with a puzzle.
Observe first. Explain later.
Anchoring phenomenon
A plant population grows quickly after rain, then levels off even while some individuals survive.
Observe silently first. Record two details you notice, one pattern, and two questions. Mark which observations are direct evidence and which statements are inferences.
How does resource availability affect individual organisms and population size?
Teacher move
Collect questions without answering the driving question. Group them by what can be observed, modeled, measured, or researched.
Misconception probe
“More of one resource always causes unlimited population growth.”
Do you agree, disagree, or need more evidence? Make an initial claim and name the evidence that could change your mind.
Map the learning path.
Questions guide the room; evidence shows the progress.
Supporting questions
- What patterns or changes can we document in the opening phenomenon?
- Which parts of resources in living systems can we represent with a model, data display, or system boundary?
- What evidence would distinguish a strong explanation from a plausible guess?
- How does the chapter model apply to use a fictionalized mojave desert rainfall and plant-abundance dataset.
Learning targets
- I can use observations and data to explain a key pattern in resources in living systems.
- I can create, interpret, or revise a model that addresses: How does resource availability affect individual organisms and population size?
- I can connect evidence to MS-LS2-1 without going beyond its assessment boundary.
- I can describe what my evidence supports, what remains uncertain, and how my thinking changed.
Words that do explanatory work
- resource
- Something an organism needs, such as food, water, light, oxygen, or space.
- resource · Use the term in a complete evidence-based sentence.
- population
- All individuals of one species living in a defined area.
- population · The ending -tion often turns a process verb into a noun.
- limiting factor
- A condition or resource that restricts growth, survival, or population size.
- limiting factor · Use the term in a complete evidence-based sentence.
- abundance
- How many organisms are present in a defined place or sample.
- abundance · Use the term in a complete evidence-based sentence.
- carrying capacity
- A model of the population size an environment can support over time.
- carrying capacity · Use the term in a complete evidence-based sentence.
Resources in Living Systems: evidence workshop
Graph an original desert annual-plant dataset and distinguish effects on individuals from effects on populations.
Materials
- Printed or projected evidence set supplied with this chapter
- Science notebook or accessible digital document
- Pencils or removable annotation tools
- Optional large paper and movable cards for group modeling
Before class
- Review the evidence set and accessibility alternatives before class.
- Decide whether students will work on paper, orally with a scribe, or in an accessible digital format.
- Post the driving question and success criteria without revealing a preferred answer.
50–65 minutes, with an optional second period for revision · Individual first notice; teams of 3–4 for analysis; individual final explanation
Procedure
- Record an individual prediction and the evidence that would be needed to test it.
- In teams, graph the supplied evidence and mark patterns, differences, and possible sources of uncertainty.
- Create a first model or evidence display connecting resource supply, organism response, population pattern.
- Exchange work with another team. Give one evidence-based challenge and one question about the model boundary.
- Revise individually, then write a short claim-evidence-reasoning explanation that answers the driving question.
Evidence task: Students organize evidence for resources in living systems, identify at least one pattern, and explain why the pattern supports or limits a claim.
Cleanup: Return reusable cards and tools, recycle unneeded paper when permitted, and leave data displays available for the explanation workshop.
Build, test, and revise an explanation.
The sketch is a thinking tool, not a picture to memorize.
A plant population grows quickly after rain, then levels off even while some individuals survive. The observation becomes scientifically useful when students separate what they can see or measure from the mechanism they are proposing.
The chapter’s core model connects resource supply, organism response, and population pattern. A strong model names the important parts, shows a relationship among them, and explains how evidence could support or challenge that relationship.
Use a fictionalized Mojave Desert rainfall and plant-abundance dataset. This is a transfer context, not proof by itself. Students should use the same science idea with new evidence and state where the model may need revision.
Formative evidence
After the launch
Circle one observation and underline one inference. What additional evidence would connect them?
Look for: Students distinguish direct evidence from an explanation or prediction.
During modeling
Point to the feature of your model that does the most explanatory work. What evidence supports it?
Look for: Students connect a model feature to a specific source of evidence.
Before final revision
Write one sentence that changed between your first and current explanation, and explain why.
Look for: Students use new evidence or critique to justify a revision.
See the standards evidence.
Labels matter less than the performance students can demonstrate.
MS-LS2-1 · primary · assesses
- Taught in
- Phenomenon launch, evidence task, and explanation workshop
- Observable performance
- Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
- Evidence artifact
- A chapter-specific model, data analysis, or explanation responding to “How does resource availability affect individual organisms and population size?”
- Assessed in
- Performance task and analytic rubric
- Boundary check
- No additional assessment boundary is stated.
SEP
- Analyzing and Interpreting Data
DCI
- LS2.A
CCC
- Cause and Effect
Resources in Living Systems evidence brief
Transfer the model to a meaningful decision or explanation.
Student performance task
A California community learning team needs a clear explanation of how does resource availability affect individual organisms and population size?
Product: Create a one-page evidence brief or a 2–3 minute accessible presentation containing a claim, annotated model or data display, linked evidence, scientific reasoning, one limitation, and a response to a reasonable counterpoint.
- Uses the chapter’s science idea accurately and within the official assessment boundary.
- Connects at least two pieces of evidence to the claim.
- Uses the emphasized science and engineering practice, DCI, and crosscutting concept together.
- Explains a limitation, uncertainty, or next evidence need.
| Dimension | Emerging | Developing | Proficient |
|---|---|---|---|
| SEP — practice | Records information but does not yet use the chapter practice to connect evidence and claim. | Uses the practice with partial evidence links or an incomplete revision. | Uses the practice strategically; evidence is analyzed, connected, and used to revise or justify. |
| DCI — science idea | Uses everyday description with a major scientific gap or unsupported mechanism. | Uses the core idea mostly accurately but leaves an important relationship unexplained. | Uses the core idea accurately to explain the phenomenon while honoring the assessment boundary. |
| CCC — relationship | Names a crosscutting concept without using it to organize reasoning. | Shows the relationship but applies it inconsistently or without a clear system boundary. | Uses the crosscutting concept to organize evidence, explain a relationship, and transfer the model. |
Reflect and revise
- What did your first model explain well?
- Which new evidence caused the most important revision?
- What does your current model still fail to explain?
- Where could this science idea matter in a California community?
Keep the intellectual work accessible.
Students collaboratively interpret evidence, explain how does resource availability affect individual organisms and population size?, and refine language that makes causal, pattern, scale, system, or matter-and-energy relationships precise.
ELD modes
Collaborative: Use partner reasoning rounds: claim, evidence, invite a challenge, then revise.
Interpretive: Annotate one data display or model with what is shown, what is inferred, and what remains uncertain.
Productive: Produce an oral, visual, or written explanation using linked evidence and scientific reasoning.
How language works: Notice how because, therefore, however, compared with, and if/then make relationships explicit.
ELD continuum
Emerging: Use labeled visuals, gestures, a bilingual glossary, and optional sentence frames before independent production.
Expanding: Combine evidence sentences with causal or contrast transitions and explain one limitation.
Bridging: Qualify claims, compare alternatives, and select discipline-appropriate language for audience and purpose.
IEP / 504
Chunk the evidence set, provide a reduced-copy workspace, read directions aloud, and allow oral, typed, drawn, or scribed evidence when the construct is preserved.
Reading access
Use short evidence captions, bold signal words, audio support, and a first-read/second-read routine.
Multilingual learners
Preview the phenomenon visually, allow rehearsal in a home language, and fade optional frames as students gain independence.
Extension
Ask students to test the model with a boundary case, compare two plausible mechanisms, or design a better evidence set.
Invite a family member to identify where resources in living systems appears in a job, hobby, home system, or local landscape. Students should bring back an observation—not personal data—and connect it cautiously to the chapter model.
Teacher plan and review.
Professional judgment is part of the design.
Facilitation notes
- Press for a link between each claim and a specific observation, measurement, or model feature.
- Ask students to name the system boundary and what the model does not show.
- Revisit the misconception probe: “More of one resource always causes unlimited population growth.”
Likely student ideas
- Students may describe only what is visible and need support connecting evidence to an unobservable mechanism.
- Students may treat a model as a picture rather than a tool for explaining or predicting.
- Some students will overstate certainty; invite them to identify a limit or alternative explanation.
Prerequisites
- Core ideas and evidence practices from Chapter 19
Literacy & mathematics
ELA: RST.6–8.1, RST.6–8.7, WHST.6–8.2
Math:
Sources for verification
- California Grade Seven Standards — Preferred Integrated Course Model · California Department of Education · accessed 2026-07-29
- Mojave National Preserve Nature · Mojave National Preserve Nature · accessed 2026-07-29
Scientific and classroom review pending. Original editorial draft. Verify local pacing, student needs, district safety procedures, citations, and standards alignment before classroom adoption.
Original educational content informed by official public standards and separately cited authoritative science sources. Reviewed 2026-07-29.