Skill: course-build → write-mcqs → write-explanation, design-check-sequence @ dea5d9e

Topic 41 — Food chains — the PP100's nine question types, with their exemplars

What this page is. James approves a bank's question TYPES before the bank is generated (vault: A bank is reviewed as its question types first, one exemplar each, 28 Sep 2026). This sheet writes the exemplars in full, exactly as they sit in content/G3T41.py (PP100, flagged TYPE_SHEET_ONLY). Nine types for three atoms, one exemplar each — under the ceiling of ten, because each atom needs two forms alone and the pairs need three. No other bank item exists yet. Once the types stand, about fifty items are generated from them, varying the chain (a fresh set of living things each time), the removed link, the names and the place, easy-heavy.

Revised 29 Sep 2026 after the non-author review (REVIEW_G3T41_2026-09-29.md): type 9 was one step (the chain handed over in order, the Sun typed) and is now a genuine two-step read — a drawn chain with the MIDDLE animal crossed out, type the living thing that goes hungry (B2); type 8's stem no longer prints its three candidate names — the drawing carries them — and its accept list is generated by name_accept() (B1); type 7's exemplar left L03's taught grass-removal scene for a moor (heather, grouse, stoat — B5); type 5's fourth option is a real belief (the sparrows eat the cabbage instead — F9); type 6 sits on a natural cause, not the headache's farmer (S11); type 4's stem no longer says "the plant first" (S8); every "where does it start" ask is now the lexicon's sentence, and "energy" appears in no stem or option (F1 — James's ruling asked on the blueprint page).

James's rulings applied. Hard items are typed, never MCQs (28 Sep night): two text-entry types, both read off a drawing with one card crossed out (the living thing there will be more of; the living thing that goes hungry). Easy and medium are four-option MCQs, plus one reorder item (your Topic 2 ruling: "you can actually use a reorder question"). Every drawn chain puts the Sun first with its yellow light arrows and runs its dark arrows from the food to the eater; no item figure carries a label, a halo or an effect chip — a removed card carries only its cross and the GONE chip (the given, not the answer). No stem leans on a video; no option bundles a verdict with a reason; every stem is a positive question; every exemplar is a fresh instance — no lesson, quiz, attached or practice scene reappears (the inventory below is the check). Nothing James has rejected appears here.

How to read a type line. Each says what the stem asks, what the four options are (the kind of thing), and gives its exemplar scene. Every MCQ has a why (no per-option feedback in the bank; the engine prints Correct / Not quite). Tags follow depth of reasoning: easy = one fact recalled on a fresh chain, or one arrow read off one drawing; medium = the rule run in a new direction (put the chain in order; predict the neighbor's change from a described removal); hard = two steps with the answer typed (read the arrow INTO the removed animal, then predict more of what it ate; read the arrow OUT of the removed animal, then predict its eater goes hungry).

The nine types

Hard because (type 8): two steps — read the arrow INTO the crossed-out card to find what that animal ate, then predict that the eaten thing grows in number — and the name is read off the drawing and typed, not picked. Hard because (type 9): two steps — read the arrow OUT of the crossed-out card to find that animal's eater (four cards, so the eater is not simply the last card), then predict that the eater goes hungry — and the name is typed. Medium because (type 4): the rule (the plant first, then each eater) is run to build an order, not to read one. Medium because (types 5, 6): the rule is applied to a fresh described case, with the two directions (the food, the eater) asked as separate items. Medium because (type 7): two atoms — the animal at the end depends on the plant at the start, through the middle link.

Bank notes for the generator. Type 1: vary the chain's living things and its length (two to four links); the biggest animal is always a distractor, because "the chain starts with the biggest animal" is the register's trap. Type 2: the distractor "food" is the trap (the Sun as food); keep it in every instance. Type 3: every drawn chain is a fresh set of living things; ask the middle animal in half the items and the last animal in the other half; vary the fourth option (the Sun, the water, the mud, a living thing not in the chain) so no option is a free elimination (review S9). Type 4: three items in a reorder, and the bank's stems never say "the plant first" (review S8); never a set whose order a child could guess from size alone (put a small eater after a big plant-eater sometimes: seagrass, sea turtle, tiger shark). Types 5 and 6: one described removal serves two items (the food, the eater) — draw at most one of the pair per test (a ⟂ pair); every type-5 case is ONE step (the removed animal's own food), never the two-step fox case (more rabbits, so less grass — the reviewer's open-item note); vary the remover — a farmer, a cold spring, a flood, a fence. Type 7: the middle animal's hunger is GIVEN in the stem, so the item asks only the last step; the key is "They go hungry." with no "too" (review F2); never the taught grass-removal scene. Type 8: the removed card is always the LAST animal and the stem names nothing — the drawing carries the names; the accept list is name_accept(<the middle animal>). Type 9: the removed card is a MIDDLE animal in a four-card chain and the stem names nothing; the accept list is name_accept(<the eater to its right>); remove the last animal and the item is type 8.

Coverage (every atom alone, and the pairs)

At most two alone-types per atom (James: "unlikely that you're going to need more than two question types per atom"). Order in the file: easy PP-1…PP-3 → medium PP-4…PP-7 → hard PP-8, PP-9. Keys of the six MCQs, in file order: PP-1 A · PP-2 B · PP-3 C · PP-5 C · PP-6 D · PP-7 A (two A, one B, two C, one D — no letter over 35 %). Typed items: 2 of 9 on the sheet; in a bank of about fifty, types 8 and 9 supply 12–15 typed items on fresh drawn chains, and medium items of types 5 and 6 may be typed too ("type the name of the living thing there will be more of").

Design-move inventory (every move on the page, then the bank's)

No bank exemplar shares a scene with a lesson, quiz, attached or practice item; no two exemplars share a move. Headache characters (Lenka, Uri, Eshan, Tillie) appear in no item; each claim-maker (Zeno, Birgit, Katya, Darcy, Willem, Greer, Mattie, Oriel, Ulyana, Dmitri, Elsbeth) is used once.

The exemplars, in full

Type 1 — PP-1 · LIF3-050 · easy

Stem: A lynx eats a hare that ate willow leaves. Where does this food chain start?

• with the Sun ← key
• with the lynx
• with the soil
• with the hare

Why: The willow is a plant, and it makes its own food using the Sun's light. / Before the plant comes the Sun. / So this food chain starts with the Sun.

Type 2 — PP-2 · LIF3-050 · easy

Stem: A tomato plant grows in a sunny garden. What does the plant get from the Sun?

• food
• light ← key
• water
• soil

Why: The Sun's light lands on the tomato plant. / The plant uses that light, and water from its roots, to make its own food. / So the plant gets light from the Sun, not food.

Type 3 — PP-3 · LIF3-051 · easy · drawing chain_pp_marsh

Stem: Look at the marsh food chain: marsh grass, cricket, frog. What does the cricket eat?

• the frog
• the Sun
• the marsh grass ← key
• the water

Why: Find the arrow that points to the cricket. / It comes from the marsh grass. / The marsh grass is eaten by the cricket. / So the cricket eats the marsh grass.

Type 4 — PP-4 · LIF3-051 · medium · reorder

Stem: Three living things live in warm shallow sea water: a tiger shark, seagrass and a sea turtle. Tap them in food chain order.

Correct order: the seagrass → the sea turtle → the tiger shark

Why: The plant comes first: seagrass makes its own food. / The sea turtle eats the seagrass. / The tiger shark eats the sea turtle. / So the order is seagrass, sea turtle, tiger shark.

Type 5 — PP-5 · LIF3-052 · medium

Stem: A farmer picks every caterpillar off her cabbages. What happens to the cabbage leaves?

• The cabbage leaves stay the same.
• There are fewer cabbage leaves.
• There are more cabbage leaves. ← key
• The sparrows eat the cabbage leaves instead.

Why: The caterpillars ate the cabbage leaves. / Now the leaves have no eater. / So there are more cabbage leaves.

Type 6 — PP-6 · LIF3-052 · medium

Stem: A cold spring means no caterpillars hatch on a farm's cabbages. What happens to the sparrows that eat caterpillars?

• They eat cabbage instead.
• They have more food.
• There are more sparrows.
• They go hungry. ← key

Why: The sparrows eat caterpillars. / This spring there are no caterpillars. / So the sparrows have lost their food and go hungry.

Type 7 — PP-7 · LIF3-052 + LIF3-050 · medium

Stem: The heather on a moor burns, and the grouse that ate it go hungry. What happens to the stoats that ate the grouse?

• They go hungry. ← key
• They eat heather instead.
• Nothing changes for the stoats.
• There are more stoats.

Why: The stoats ate the grouse. / The grouse went hungry, so there are fewer grouse. / So the stoats have lost their food, and they go hungry.

Type 8 — PP-8 · LIF3-052 + LIF3-051 · hard · text entry · drawing chain_pp_kelp_no_otter

Stem: Look at this food chain. One living thing is crossed out: it is gone. Type the name of the living thing there will now be more of.

Drawing: Sun · kelp → sea urchin → sea otter, the sea otter crossed out with a chip GONE.

Accept: name_accept("sea urchin") — sea urchin · the sea urchin · sea urchins · the sea urchins · a sea urchin · urchin · the urchin · urchins · the urchins · an urchin (the grader folds case)

Why: The crossed-out card is the sea otter. / The arrow into the sea otter comes from the sea urchin, so the otter ate the urchin. / With the otters gone, the urchins have no eater. / So there are more sea urchins.

Hard because: two steps — read the drawing to find the crossed-out animal and the arrow into it, then predict — and the name is typed, not picked from a stem that names it.

Type 9 — PP-9 · LIF3-052 + LIF3-051 · hard · text entry · drawing chain_pp_cactus_no_lizard

Stem: Look at this food chain. One living thing is crossed out: it is gone. Type the name of the living thing that goes hungry.

Drawing: Sun · prickly pear → beetle → lizard → roadrunner, the lizard crossed out with a chip GONE.

Accept: name_accept("roadrunner") — roadrunner · the roadrunner · roadrunners · the roadrunners · a roadrunner (the grader folds case)

Why: The crossed-out card is the lizard. / The arrow out of the lizard points to the roadrunner, so the roadrunner ate the lizard. / With the lizards gone, the roadrunner has lost its food. / So the roadrunner goes hungry.

Hard because: two steps — read the arrow OUT of the crossed-out card to find its eater (four cards, so the eater is not simply the last one), then predict — and the name is typed.