# Food-web change explorer

Year 7 Science · Term 1 · Weeks 5–6 · Days 21–30 · ten optional 50-minute starts, each usable as two 25-minute sittings.

Make a useful food-web explainer from the first lesson: a paper network, spoken/described network, or learner-directed model. Choose a path, ask what might change, and show why a prediction needs conditions. One sound link or explanation component is a useful start; return later if wanted.

## Start with little preparation

Read [MATERIALS](MATERIALS.md) and [the short source capsules](SOURCE-CAPSULES.md). Use two existing broad sheets and any approved marker, or read the named nodes aloud. No device, print, live organism, field trip, cutting or purchase is needed. A teacher reads source capsules if full linked sources are unavailable. They are original factual paraphrases, not copies of expert images or tables. Keep [fresh checks](STUDENT-CHECKS.md) and the [separate teacher key](teacher/ANSWER-AND-NEXT.md) out of ordinary modelling until Days 25/30. No ordinary task uses either held graph.

[Ten plans](LESSONS.md) · [30 switchable routes](DAILY-CHOICES.md) · [learner page](LEARNER.md) · [20 worked contexts](EXAMPLE-BANK.md) · [home and extras](DAILY-EXTRAS.md) · [eight printable pairs and exact alternatives](print/TEXT-ALTERNATIVES.md) · [source and rights](SOURCE-AND-RIGHTS.md) · [exact crosswalk](CURRICULUM-CROSSWALK.md) · [desk/render/verification record](QA-RUN-THROUGH.md).

The Museum source download is currently unavailable. The dated access note in [SOURCE-CAPSULES](SOURCE-CAPSULES.md#source-access-on-1-october-2026) explains what was checked. Everything needed for the ten starts is supplied here; no external download is required.

## Prepared opportunity and actual evidence

The ordinary web combines documented feeding possibilities into an original illustrative model. It is not a surveyed ecosystem, verified local co-occurrence, population census or prediction of an actual site. A learner can actually read, construct, compare, explain or revise this model. Moving a node does not conduct an ecosystem experiment. Record learner reasoning and support concisely; adult enactment, an unmade plan, observed model work, actual field observation and audience feedback remain different.

This leaf extends the earlier invented classification keys and brief food-web practice with resource-specific feeding links, matter/energy distinctions, alternate paths and conditional change predictions. It does not change the integrated year map or certify Year 7, every inquiry skill, all states or a full achievement standard. Untagged PDFs have exact linear/no-print alternatives; individual access, local materials and classroom pacing need human review.

## Reproduce and check

From this folder: `PYTHONDONTWRITEBYTECODE=1 python3 verify_pack.py`. The default checks source/lesson/graph/rights/print/link/hash scope, makes 17 genuinely regenerated outputs in a temporary directory and tests meaningful faults in temporary copies. It does not write the authored pack. To intentionally refresh the inventory after an authorised edit: `python3 verify_pack.py --write-manifest`. To make print files in a separate empty directory: `python3 make_printables.py --output /tmp/food-web-print-review`. Commands do not rely on a private workstation path; use an available temporary directory. Python, Pillow, pypdf and installed rsvg-convert are required; no new dependency installation is part of this pack.