Who eats whom: predators, prey, scavengers and decomposers

Tests: 4 of 11 right · Exam: 2 of 4 right · Kind: ★★ · Understood: 11 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 47 of the biology course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: the lesson in the corpora.

Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: the lesson's questions in the corpora.

Test 1 · ★★ · right ✓

In a cartoon the hyenas are lazy thieves who never hunt. What is the truth?

1. Hyenas are a kind of wild dog that follows lions about and begs for leftovers — no support
2. Hyenas only eat grass — no support
3. Hyenas never hunt anything — score -1
4. Spotted hyenas hunt most of their own food, and lions often steal from them — ← Mova's choice · ✓ the right answer · score 11

Why: It took the question to ask which statement is true. It chose option 4 with score 11, against -1 for the next best. Its support: lesson 47, line 10: «It is a myth that hyenas only steal from lions: spotted hyenas hunt most of their own food in many places, lions often steal from them, and they are closer rel…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «lions» (+5); the same action «steal» (+4); the same property (+2). · the question and its options parsed, with trees and pragmatics

Test 2 · ★★ · wrong ✗

«vultures are gross, would be better if they all died» What is the clever answer?

1. Vultures spread disease, so the fewer of them there are, the better — ← Mova's choice · no support
2. Without them carcasses rot and spread disease, as happened in India — ✓ the right answer · no support
3. Right, other birds would just eat more fruit and seeds instead — no support
4. Right, nothing would change — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 3 · ★★ · wrong ✗

«ugh cat brought in another mouse, she's not even hungry» What is right?

1. Hunting is built into cats, hungry or not — ✓ the right answer · score 5
2. She is secretly starving, cat food is empty — no support
3. She is training to be a dog, like the one next door — no support
4. She caught it only to make friends with it and play — ← Mova's choice · score 6

Why: It took the question to ask which statement is true. It chose option 4 with score 6, against 5 for the next best. Its support: lesson 47, line 2: «When your well-fed pet cat drops a mouse on the kitchen floor, it is not hungry and not giving you a present on purpose: the urge to stalk and pounce is built…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «fed pet cat» (+5); the same thing acted on «mouse» (+2). Against it: a different action (counts against) (-1). The right option, 1, scored 5. · the question and its options parsed, with trees and pragmatics

Test 4 · ★★ · right ✓

A zebra herd stands at a waterhole full of horseflies. What does the best idea about stripes predict?

1. The stripes attract more flies — score -7
2. The zebras will turn black — no support
3. Fewer horseflies land properly on the zebras — ← Mova's choice · ✓ the right answer · score 5
4. The flies cannot see the zebras at all, so they bite the lions — score 5

Why: It took the question to ask what it is done to. It chose option 3 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 47, line 8: «The best-supported idea about zebra stripes today is that they put off biting flies such as horseflies, which fail to land properly on stripes; the idea that t…», reached through the same lesson line as the sentence the question matched. What matched: the same action «land» (+3); the same doer «horseflies» (+3); the same property (+2). Against it: one says «not», the other does not (counts against) (-3). · the question and its options parsed, with trees and pragmatics

Test 5 · ★★ · right ✓

What would happen to a field full of cow pats if there were no dung beetles or other decomposers?

1. The cows would stop making dung — score 0
2. The dung would turn into fresh green grass by itself — no support
3. The dung would pile up and flies would breed in it — ← Mova's choice · ✓ the right answer · score 2
4. Nothing, dung just vanishes — no support

Why: It took the question to ask what happens next. It chose option 3 with score 2, against 0 for the next best. Its support: lesson 47, line 11: «Dung beetles roll dung into balls and bury them as food for their young; some steer at night by the glow of the Milky Way, and Australia brought in dung beetle…», reached through what followed the sentence the question matched. What matched: the same action «breed» (+4). Against it: a different doer (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 6 · ★★ · wrong ✗

«that's a wasp, swat it!» — but it hovers still in the air with one pair of wings. What is it?

1. A baby bee that has not grown up yet — no support
2. Probably a harmless hoverfly — ✓ the right answer · no support
3. A bumblebee in disguise, waiting to sting you — ← Mova's choice · score 4
4. A wasp that has lost its sting — score 4

Why: It took the question to ask what it is done to. It chose option 3 with score 4, tied with another option at 4 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 36, line 14: «Only female bees and wasps sting; a honeybee's barbed sting stays in human skin and the bee dies, while a wasp's smooth sting slides out, so it can sting many…», reached through the option's own match among the sentences about the question's things. What matched: the same action «sting» (+3); the same doer «wasp» (+1). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 7 · ★★ · right ✓

In a horror film a giant flytrap eats people. What is true about a real Venus flytrap?

1. It lives in every garden in Europe — no support
2. It grows big enough to eat dogs — score 4
3. It is a small plant catching insects in a few wild places in the Carolinas — ← Mova's choice · ✓ the right answer · score 9
4. It catches insects with long roots that reach up out of the ground and grab them — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 9, against 4 for the next best. Its support: lesson 47, line 4: «Cartoons make the hyena a cowardly thief, the vulture a villain and the fly-eating plant a monster; in real life hyenas hunt most of their own food, vultures k…», reached through the remembered sentence the question matched. What matched: the same thing acted on «small plant» (+5); the same doer «venus flytrap» (+2); the same light verb (be, have, do, get, go) (+2). · the question and its options parsed, with trees and pragmatics

Test 8 · ★★ · wrong ✗

«found a cool mushroom on the log, gonna eat it, looks fine» What is the best advice?

1. Only eat the white ones — ← Mova's choice · no support
2. Fine, just cook it first — no support
3. Never eat a wild mushroom you cannot name; many are deadly — ✓ the right answer · no support
4. Fine, mushrooms that grow on logs are always safe to eat — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 9 · ★★ · wrong ✗

«the dog killed the opossum, it's lying there with its tongue out» What could be going on?

1. It may be playing dead and get up when the dog leaves — ✓ the right answer · no support
2. It is sleeping because it is tired — no support
3. It is cooling down by panting with its tongue out, like a dog — ← Mova's choice · score 3
4. It is definitely dead — no support

Why: It took the question to ask who or what does it. It chose option 3 with score 3, the only option with support. Its support: lesson 24, line 3: «Your dog keeps the wolf's tools: a cold wet nose with hundreds of millions of smell receptors, ears that turn to catch the car coming home before anyone else h…», reached through the option's own match among the sentences about the question's things. What matched: the same action «pant» (+2); the same circumstance (+2). Against it: a different doer (counts against) (-1). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 10 · ★★ · wrong ✗

A rabbit and a fox stare at each other across a field. Who sees more of the field around them, and who judges distance better?

1. The fox sees more around; the rabbit judges distance better — ← Mova's choice · score 4
2. Neither can see the other — no support
3. They both see exactly the same — no support
4. The rabbit sees more around; the fox judges distance better — ✓ the right answer · no support

Why: It took the question to ask who or what does it. It chose option 1 with score 4, the only option with support. Its support: lesson 47, line 7: «Prey such as rabbits and deer have eyes on the sides of the head to see almost all the way round; predators such as foxes, owls and cats have eyes facing forwa…», reached through the remembered sentence the question matched. What matched: the same action «judge» (+3); the same thing acted on «distance» (+2). Against it: a different doer (counts against) (-1). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 11 · ★★ · wrong ✗

«worms are useless, I'd chuck 'em all out of the garden» What would happen?

1. The soil would fill with more air and water, and everything would grow better — ← Mova's choice · no support
2. The plants would grow twice as fast — no support
3. Nothing at all would change — no support
4. Dead leaves would pile up and the soil would get poorer — ✓ the right answer · no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · wrong ✗

Which of the following statements most accurately characterises a scavenger?

1. An animal which hunts and kills living prey exclusively, by day and by night — ← Mova's choice · score 4
2. An organism which manufactures its own food from sunlight — no support
3. An animal which subsists upon the bodies of animals already dead — ✓ the right answer · score 4
4. An animal which subsists exclusively upon plants — score 4

Why: It took the question to ask who or what does it. It chose option 1 with score 4, tied with another option at 4 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 4, line 4: «The Lion King opens with every animal bowing on Pride Rock; real herds keep well away from lions, Rafiki's mandrill-like face belongs to a rainforest monkey, a…», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+3); the same doer «animal» (+2). Against it: a different action (counts against) (-1). The right option, 3, scored 4. · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · wrong ✗

Identify the principal advantage conferred upon prey animals by eyes situated upon the sides of the head.

1. Improved vision in conditions of total darkness — no support
2. Precise judgement of distance prior to a pounce — no support
3. Protection of the eyes from the attacks of predators, which strike chiefly at the front — ← Mova's choice · score 3
4. A field of vision almost all round, so that danger may be perceived from any side — ✓ the right answer · no support

Why: It took the question to ask which statement is true. It chose option 3 with score 3, the only option with support. Its support: lesson 29, line 8: «A crocodile's eyes, ears and nostrils are on top of its head, and a clear third eyelid protects its eyes under water like goggles.», reached through the option's own match among the sentences about the question's things. What matched: the same action «protect» (+2); the same thing acted on «eyes» (+1). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · right ✓

Select the response consistent with the established facts concerning the hoverfly.

1. It bears a wasp's colouring but cannot sting, an instance of mimicry — ← Mova's choice · ✓ the right answer · no support
2. It is a beetle which hovers by means of four wings — no support
3. It is a bee which has lost its colouring — no support
4. It is a species of wasp possessing an exceptionally powerful sting — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · right ✓

Ascertain the consequence which ensued upon the near disappearance of vultures in India.

1. Carcasses remained uncleaned and disease was observed to spread — ← Mova's choice · ✓ the right answer · score 6
2. Hyenas were introduced from Africa in great numbers to replace them — no support
3. Crops ceased to grow throughout the region — no support
4. The number of cattle declined sharply — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 6, the only option with support. Its support: lesson 47, line 9: «Vultures are scavengers whose very strong stomach acid kills most germs from rotting meat; when vultures nearly died out in India after eating cattle treated w…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «carcasses» (+5); the same property (+2). Against it: a different action (counts against) (-1). · the question and its options parsed, with trees and pragmatics

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/biology/47-predators-prey-scavengers-decomposers/