---
title: Food chains: sun, plants, plant-eaters, meat-eaters — how Mova does on the tests · Biology
description: Lesson 46 of the biology course of Mova's primary school: 8 of 11 tests right, exam 2 of 4, every question with the options, the student's choice, the right answer and why it chose.
---

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# Food chains: sun, plants, plant-eaters, meat-eaters

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**Tests:** 8 of 11 right · **Exam:** 2 of 4 right · **Kind:** ★ · **Understood:** 12 of 15 · **Run:** 2026-10-18, commit `f3c23ea72`

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Lesson 46 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](https://md.mova.elamur.ai/free/en/corpora/school/biology/46-food-chains/).

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Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/).

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### Test 1 · ★ · right ✓ {#t1}

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«food chain: fox → rabbit → grass, cos the fox is the boss» What is wrong?

- **1.** Arrows go from food to eater: grass to rabbit to fox — **← Mova's choice** · **✓ the right answer** · no support
- **2.** The grass should be at the top because it is the biggest thing in the field — no support
- **3.** Nothing, that is right — no support
- **4.** The rabbit eats the fox — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t1/)

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### Test 2 · ★ · wrong ✗ {#t2}

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In a cartoon a lion eats grass with the zebras every day. Where does a real lion get its energy?

- **1.** From the sunshine on its mane — **← Mova's choice** · score 4
- **2.** From the water it drinks — no support
- **3.** From the grass, like the zebras, only it eats a lot more of it — no support
- **4.** From eating plant-eaters, which got it from plants and the Sun — **✓ the right answer** · score 4

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**Why:** It took the question to ask where. 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 18, line 15: «Lions rest or sleep up to about 20 hours a day to save energy for hunting, and a lion can eat 30 kilograms or more at one meal and then not eat for days.», reached through the remembered sentence the question matched. What matched: the same doer «lions» (+2); the same thing acted on «energy» (+2). The right option, 4, scored 4. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t2/)

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### Test 3 · ★ · right ✓ {#t3}

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«why isn't there a super-lion that eats lions» What is the best answer?

- **1.** Lions are too fast and too strong for anything to catch — no support
- **2.** Too little energy is left at the top of a chain to feed it — **← Mova's choice** · **✓ the right answer** · score 2
- **3.** Lions are poisonous — no support
- **4.** There is one, but it hides really well in caves — no support

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**Why:** It took the question to ask why something happens (its cause). It chose option 2 with score 2, the only option with support. Its support: lesson 18, line 15: «Lions rest or sleep up to about 20 hours a day to save energy for hunting, and a lion can eat 30 kilograms or more at one meal and then not eat for days.», reached through the same lesson line as the sentence the question matched. What matched: the same doer «lions» (+3); the same thing acted on «energy» (+1). Against it: a different action (counts against) (-2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t3/)

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### Test 4 · ★ · right ✓ {#t4}

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What would happen to the foxes if a disease killed most of the rabbits in a field?

- **1.** The foxes would start eating grass only, like the rabbits used to — score 3
- **2.** They would eat more mice, beetles and fruit, or go hungry — **← Mova's choice** · **✓ the right answer** · score 6
- **3.** There would be more foxes than before — no support
- **4.** Nothing, foxes do not eat rabbits — score 3

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**Why:** It took the question to ask what happens next. It chose option 2 with score 6, against 3 for the next best. Its support: lesson 46, line 12: «A real fox eats rabbits, mice, birds, worms, beetles, fruit and leftovers, so food chains join into a tangled food web, which lets animals switch food when one…», reached through the option's own match among the sentences about the question's things. What matched: the same action «eat» (+2); the same doer «real fox» (+2); the same thing acted on «rabbits» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t4/)

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### Test 5 · ★ · right ✓ {#t5}

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«mate reckons plants eat the soil to grow, that's why they need it» What is right?

- **1.** No, plants make food from light, air and water; soil gives water and minerals — **← Mova's choice** · **✓ the right answer** · score 6
- **2.** Yes, plants eat soil — score 1
- **3.** No, plants need nothing at all to grow — score 3
- **4.** Yes, the roots chew the soil up slowly and swallow it bit by bit, mate — no support

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**Why:** It took the question to ask why something happens (its cause). It chose option 1 with score 6, against 3 for the next best. Its support: lesson 46, line 5: «Plants make their own food from sunlight, water and carbon dioxide; this is photosynthesis, it uses the green chlorophyll in leaves and gives out oxygen; plant…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «plants» (+3); the same action «make» (+2); the same thing acted on «own food» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t5/)

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### Test 6 · ★ · right ✓ {#t6}

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Where does the energy in your cheese sandwich come from in the end?

- **1.** The salt in the bread — no support
- **2.** The electricity used by the cheese factory and the bakery — no support
- **3.** The fridge — no support
- **4.** The Sun, through wheat and through grass eaten by a cow — **← Mova's choice** · **✓ the right answer** · score 8

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**Why:** It took the question to ask where. It chose option 4 with score 8, the only option with support. Its support: lesson 46, line 3: «Look at your cheese sandwich: the bread was wheat that grew in sunshine, the cheese came from milk from a cow that ate grass, so you are at the end of food cha…», reached through the same lesson line as the sentence the question matched. What matched: the same action «eat» (+3); the same thing acted on «grass» (+3); the same circumstance (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t6/)

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### Test 7 · ★ · right ✓ {#t7}

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«sea's just water, it doesn't make oxygen» What is right?

- **1.** Oxygen comes only from volcanoes — no support
- **2.** Phytoplankton in the sea make roughly half of Earth's oxygen — **← Mova's choice** · **✓ the right answer** · score 6
- **3.** Right, all of Earth's oxygen comes from the rainforests on land — no support
- **4.** Right, the sea uses up all oxygen — score 2

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**Why:** It took the question to ask which statement is true. It chose option 2 with score 6, against 2 for the next best. Its support: lesson 46, line 10: «Tiny drifting algae and bacteria called phytoplankton are the producers of the ocean, and they make roughly half of the oxygen produced on Earth.», reached through the same lesson line as the sentence the question matched. What matched: the same action «make» (+4); the same thing acted on «half» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t7/)

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### Test 8 · ★ · wrong ✗ {#t8}

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«why'd they bring wolves back, they'll just eat stuff» What did scientists see?

- **1.** The wolves made the rivers dry up — no support
- **2.** The wolves ate every single animal in the park, then started on each other — **← Mova's choice** · score 3
- **3.** Nothing at all happened — no support
- **4.** Elk grazed differently and some young trees grew back, though how much is argued — **✓ the right answer** · no support

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**Why:** It took the question to ask why something happens (its cause). It chose option 2 with score 3, the only option with support. Its support: lesson 24, line 1: «Every pet dog, from a tiny chihuahua to a Great Dane, comes from wolves that began living alongside people more than 15,000 years ago; people kept the friendli…», reached through the option's own match among the sentences about the question's things. What matched: the same action «begin» (+2); the same doer «wolves» (+1). The right option, 4, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t8/)

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### Test 9 · ★ · right ✓ {#t9}

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A sea otter floats on its back cracking a sea urchin. Why is that good for the kelp forest?

- **1.** The broken urchin shells sink and feed the kelp — no support
- **2.** It is not, because otters eat lots of kelp too — score 1
- **3.** Otters plant new kelp using their little stones — no support
- **4.** Fewer urchins means less kelp gets eaten — **← Mova's choice** · **✓ the right answer** · score 3

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**Why:** It took the question to ask why something happens (its cause). It chose option 4 with score 3, against 1 for the next best. Its support: lesson 46, line 14: «Sea otters eat sea urchins, which eat kelp; where otters live kelp forests grow tall, and without them urchins can chew kelp down to bare rock.», reached through the same lesson line as the sentence the question matched. What matched: the same action «eat» (+2); the same thing acted on «kelp» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t9/)

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### Test 10 · ★ · wrong ✗ {#t10}

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«a whole field of wheat feeds more people than the same field feeding cows, why» What is right?

- **1.** Energy is lost at each step, so eating plants directly wastes less — **✓ the right answer** · score 3
- **2.** Wheat has more energy than any meat ever could, so it fills you up more — no support
- **3.** Cows eat less than people — **← Mova's choice** · score 5
- **4.** Cows make energy from sunlight — no support

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**Why:** It took the question to ask why something happens (its cause). It chose option 3 with score 5, against 3 for the next best. Its support: lesson 46, line 3: «Look at your cheese sandwich: the bread was wheat that grew in sunshine, the cheese came from milk from a cow that ate grass, so you are at the end of food cha…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «cow» (+3); the same action «eat» (+2). The right option, 1, scored 3. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t10/)

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### Test 11 · ★ · right ✓ {#t11}

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«deep sea worms live on sunlight too, everything does» What is right?

- **1.** No, deep sea worms do not eat at all — no support
- **2.** No, at hot vents bacteria make food from chemicals, not light — **← Mova's choice** · **✓ the right answer** · score 14
- **3.** Yes, the worms glow in the dark and make their own little bit of sunlight — no support
- **4.** Yes, sunlight reaches the deepest sea — score 2

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**Why:** It took the question to ask which statement is true. It chose option 2 with score 14, against 2 for the next best. Its support: lesson 46, line 15: «Near hot springs on the deep sea floor, found in 1977, food chains start with bacteria that make food from chemicals instead of sunlight; giant tube worms have…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «bacteria» (+5); the same action «make» (+4); the same place «chemicals» (+3); the same thing acted on «food» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/t11/)

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### Exam question 1 · formal language · right ✓ {#e1}

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Which of the following statements most accurately characterises the process of photosynthesis?

- **1.** The making by plants of food from water and carbon dioxide by sunlight, releasing oxygen — **← Mova's choice** · **✓ the right answer** · score 7
- **2.** The absorption by plants of food already present in the soil, by means of the roots — score 4
- **3.** The conversion by plants of oxygen into soil — score 4
- **4.** The consumption by plants of insects for nourishment — score 4

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**Why:** It took the question to ask who or what does it. It chose option 1 with score 7, against 4 for the next best. Its support: lesson 46, line 5: «Plants make their own food from sunlight, water and carbon dioxide; this is photosynthesis, it uses the green chlorophyll in leaves and gives out oxygen; plant…», 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 action «make» (+2); the same doer «plants» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/e1/)

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### Exam question 2 · formal language · right ✓ {#e2}

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Identify the principal reason for which food chains are seldom longer than five steps.

- **1.** At each step most energy is expended, so too little remains for further steps — **← Mova's choice** · **✓ the right answer** · score 3
- **2.** Plants cease to grow when a chain exceeds five steps — no support
- **3.** Predators are prohibited by their nature from consuming other predators — no support
- **4.** Animals at the summit of a chain require no food — no support

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 3, the only option with support. Its support: lesson 46, line 4: «At each step most of the energy is used up for moving, breathing and keeping warm, so there are always far more zebras than lions, and a cartoon savanna with a…», reached through the option's own match among the sentences about the question's things. What matched: the same action «use up» (+2); the same circumstance (+2). Against it: a different thing acted on (counts against) (-1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/e2/)

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### Exam question 3 · formal language · wrong ✗ {#e3}

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Select the response consistent with the established facts concerning the diet of the blue whale.

- **1.** It subsists principally upon seals, squid and large fish pursued at great depth — **← Mova's choice** · no support
- **2.** It subsists upon seaweed torn from the sea floor — no support
- **3.** It subsists almost entirely upon krill, small crustaceans which eat drifting algae — **✓ the right answer** · no support
- **4.** It subsists upon other species of whale — no support

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**Why:** Nothing it remembers matched the question, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/e3/)

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### Exam question 4 · formal language · wrong ✗ {#e4}

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Ascertain the origin of food in the communities surrounding hot springs upon the deep sea floor.

- **1.** Sunlight which penetrates to the greatest depths — **← Mova's choice** · no support
- **2.** Food discarded from vessels upon the surface — no support
- **3.** Plants which flourish in darkness by means of the heat of the springs — no support
- **4.** Bacteria which make food from chemicals dissolved in the heated water — **✓ the right answer** · no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/biology/46-food-chains/e4/)

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- ← previous: [45. More record-breakers and oddballs: sloth, narwha…](https://md.mova.elamur.ai/free/en/school-run/biology/45-sloth-narwhal-chameleon-eel-giraffe/)
- next →: [47. Who eats whom: predators, prey, scavengers and d…](https://md.mova.elamur.ai/free/en/school-run/biology/47-predators-prey-scavengers-decomposers/)
- ↑ back to [Biology](https://md.mova.elamur.ai/free/en/school-run/biology/)