This pack supports fair, consistent marking of the Build an Ecosystem task. It contains a model exemplar, an annotated marking guide for each rubric criterion, a worked on-balance judgement, and notes for marking adjusted responses. It is for teacher and moderation use — it is not shown to students before the task.
Model exemplar response (a "High" answer)
Part A — the diagram. A tree-based bush ecosystem showing: a gum tree and grass (producers); a honey possum and a rock wallaby (consumers) and a wedge-tailed eagle (a second-level consumer); and a mushroom/fungus and an earthworm (decomposers). Two clear food chains are drawn with arrows pointing to the eater:
Part B — roles table (model):
| Living thing | Role |
|---|---|
| Gum tree / grass | Producer |
| Rock wallaby / honey possum | Consumer |
| Wedge-tailed eagle | Consumer (eats other animals) |
| Fungus / earthworm | Decomposer |
Part C (model). "The grass is a producer — it uses energy from the Sun to make its own food. The rock wallaby is a consumer that eats the grass, so energy passes from the grass to the wallaby. The wedge-tailed eagle eats the wallaby, so the energy passes on again. The fungus is a decomposer: when a plant or animal dies it breaks the body down and returns the nutrients to the soil, which the grass uses to grow. So energy and nutrients keep cycling."
Part D (model). "If the grass disappeared, the rock wallaby would have much less to eat, so there would be fewer wallabies. Then the wedge-tailed eagle would have fewer wallabies to hunt, so it might go hungry or leave. The whole ecosystem is connected, so removing one producer affects the animals above it in the chain."
Comprehensive marking guide — applying the four criteria
1. Roles: producers, consumers and decomposers (30)
| Band | What you should see |
|---|---|
| High (5–6) | Ecosystem includes producers, consumers and at least one decomposer, all correctly labelled with roles. |
| Sound (3–4) | All three types present; most roles labelled correctly (a slip or two). |
| Limited (1–2) | Some living things present; few or incorrect role labels; decomposer often missing. |
Look for / common issues: the decomposer is the most-often-omitted role; a "Limited" script frequently has only plants and one animal. Do not penalise unusual but valid choices (e.g. a beetle as a decomposer).
2. Food chains and the flow of energy (30)
| Band | What you should see |
|---|---|
| High (5–6) | Two or more accurate chains; arrows correctly point to the eater; energy flow explained beginning with the Sun. |
| Sound (3–4) | Chains with mostly correct arrows; energy flow described but may not start at the Sun. |
| Limited (1–2) | A simple chain; arrows may be reversed; energy flow unclear. |
Look for / common issues: reversed arrows are the single most common error — check direction carefully. Crediting "starts with the Sun" distinguishes High from Sound.
3. Ecological relationships and change (25)
| Band | What you should see |
|---|---|
| High (5–6) | Clear decomposer role (returns nutrients) and well-reasoned flow-on effects when a living thing is removed. |
| Sound (3–4) | Explains the decomposer's role and describes one likely effect of removal. |
| Limited (1–2) | States a role and/or an effect with little reasoning. |
Look for: the word "because" and a traced consequence ("fewer grass → fewer wallabies → hungry eagle") signals High reasoning.
4. Communication and scientific vocabulary (15)
| Band | What you should see |
|---|---|
| High (3) | Clear, logical ideas using correct terms (producer, consumer, decomposer, energy, nutrients, ecosystem) throughout. |
| Sound (2) | Clear with some scientific vocabulary. |
| Limited (1) | Unclear, or little scientific vocabulary. |
Worked on-balance judgement
Marking adjusted (ABLEWA) responses
Where a student used the additional-support approach (card-based build, AAC, scribed or symbol-choice answers), mark the science evidence, not the mode. A correctly placed card chain with an arrow to the eater is valid evidence for the Food-chain criterion; a yes/no reasoned response to a "what if" is valid for Ecological relationships at an emerging level. Record the adjustments beside the result so the judgement can be moderated. Refer to the lesson's additional-support approach for the Stage A–D descriptors.