---
title: The ocean: open sea, sunlit zone and the deep dark — how Mova does on the tests · Biology
description: Lesson 8 of the biology course of Mova's primary school: 5 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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[home](https://md.mova.elamur.ai/free/en/) / [at school](https://md.mova.elamur.ai/free/en/school-run/) / [Biology](https://md.mova.elamur.ai/free/en/school-run/biology/) / 8

# The ocean: open sea, sunlit zone and the deep dark

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**Tests:** 5 of 11 right · **Exam:** 2 of 4 right · **Kind:** ★ · **Understood:** 7 of 15 · **Run:** 2026-10-18, commit `f3c23ea72`

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Lesson 8 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/8-the-ocean/).

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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/8-the-ocean/).

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### Test 1 · ★ · right ✓ {#t1}

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«jaws was real basically, sharks hunt people» What is right?

- **1.** Yes, but only in summer, when lots of people swim in the sea and sharks follow the smell of suncream — no support
- **2.** No, sharks are vegetarian — no support
- **3.** Yes, every shark hunts people — no support
- **4.** Attacks are very rare; people kill far more sharks than sharks kill people — **← Mova's choice** · **✓ the right answer** · score 4

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**Why:** It took the question to ask which statement is true. It chose option 4 with score 4, the only option with support. Its support: lesson 8, line 4: «In Jaws one shark terrorises a whole town, but real shark attacks are very rare, most of the 500 or so kinds of shark are smaller than a person, and people cat…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «real shark attacks» (+2); the same property (+1); the same light verb (be, have, do, get, go) (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/8-the-ocean/t1/)

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### Test 2 · ★ · wrong ✗ {#t2}

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«biggest fish = scariest teeth, has to be» What is right?

- **1.** Yes, the whale shark eats seals and dolphins with its huge teeth — **← Mova's choice** · score 3
- **2.** The biggest fish is the blue whale — no support
- **3.** The biggest fish, the whale shark, filters tiny plankton — **✓ the right answer** · no support
- **4.** The biggest fish is the great white — 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 7, line 10: «The leopard seal, about 3.5 metres long, eats krill, fish, penguins and other seals, and its back teeth lock together like a sieve to strain krill.», reached through the same lesson line as the sentence the question matched. What matched: the same action «eat» (+2); the same thing acted on «krill» (+2). Against it: a different doer (counts against) (-1). The right option, 3, 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/8-the-ocean/t2/)

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### Test 3 · ★ · wrong ✗ {#t3}

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Count them: two octopuses and a squid in the aquarium. How many hearts?

- **1.** 6 — **← Mova's choice** · no support
- **2.** 4 — no support
- **3.** 3 — no support
- **4.** 9 — **✓ 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/8-the-ocean/t3/)

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### Test 4 · ★ · wrong ✗ {#t4}

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Count them: an octopus and a squid side by side. How many arms and tentacles altogether?

- **1.** 10 — **← Mova's choice** · no support
- **2.** 18 — **✓ the right answer** · no support
- **3.** 16 — no support
- **4.** 20 — 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/8-the-ocean/t4/)

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### Test 5 · ★ · wrong ✗ {#t5}

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In Finding Nemo the anglerfish has a glowing lure on its head. Which part is right?

- **1.** The lure does glow, lit by bacteria living inside it — **✓ the right answer** · score 9
- **2.** Anglerfish live in sunny shallow reefs — **← Mova's choice** · score 10
- **3.** Anglerfish lure prey with a song — score 9
- **4.** The light comes from a swallowed lightbulb that still works — no support

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**Why:** It took the question to ask who or what does it. It chose option 2 with score 10, against 9 for the next best. Its support: lesson 8, line 5: «In Finding Nemo the anglerfish that chases Marlin and Dory is a good likeness: a big female with a glowing lure on her head, and a real male anglerfish of some…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same doer «anglerfish» (+4). The right option, 1, scored 9. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/8-the-ocean/t5/)

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### Test 6 · ★ · wrong ✗ {#t6}

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What would happen to Everest if you dropped it into the Challenger Deep?

- **1.** It would float back up — **← Mova's choice** · no support
- **2.** Its peak would stick out of the sea by about 2 km — no support
- **3.** It would fill the trench right up to the top and spill over — no support
- **4.** Its peak would still be about 2 km under 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/8-the-ocean/t6/)

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### Test 7 · ★ · wrong ✗ {#t7}

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«nothing could live down the mariana trench, pressure'd squash it» What is right?

- **1.** Only giant squid live there — **← Mova's choice** · no support
- **2.** Some fish, shrimp-like animals and microbes still live there — **✓ the right answer** · no support
- **3.** Only plants can live there, as animals would be squashed flat by the water — no support
- **4.** Nothing at all lives below 1 km — 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/8-the-ocean/t7/)

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### Test 8 · ★ · right ✓ {#t8}

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«sea's massive, a few plastic bags won't do anything» Which is the best answer?

- **1.** Plastic sinks to the bottom of the sea and never harms anything that lives down there — no support
- **2.** Turtles eat bags like jellyfish, and microplastics are found everywhere — **← Mova's choice** · **✓ the right answer** · score 3
- **3.** Fish eat plastic and grow bigger — no support
- **4.** Plastic melts in seawater in a day — no support

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**Why:** It took the question to ask which statement is true. It chose option 2 with score 3, the only option with support. Its support: lesson 8, line 15: «Sea turtles eat jellyfish and can mistake floating plastic bags for them; plastic can block the stomach so the turtle feels full and starves, and tiny micropla…», reached through the option's own match among the sentences about the question's things. What matched: the same doer «sea turtles» (+2); the same thing acted on «floating plastic bags» (+2). Against it: a different action (counts against) (-1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/8-the-ocean/t8/)

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### Test 9 · ★ · right ✓ {#t9}

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«octopus has 8 legs and one heart like everything else» What is right?

- **1.** It has 8 arms, 3 hearts and blue blood — **← Mova's choice** · **✓ the right answer** · score 10
- **2.** It has 6 arms, 3 hearts and bright red blood — score 10
- **3.** It has 10 legs, 2 hearts and green blood — score 10
- **4.** It has 8 legs, no heart at all and clear blood — score 10

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 10, tied with another option at 10 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 8, line 12: «An octopus has no bones, so it can squeeze through any gap bigger than its hard beak; it has 3 hearts, 8 arms and blue blood, and most of its nerve cells are i…», reached through the remembered sentence the question matched. What matched: the same doer «octopus» (+4); the same thing acted on «3 hearts» (+4); the same light verb (be, have, do, get, go) (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/8-the-ocean/t9/)

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### Test 10 · ★ · right ✓ {#t10}

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«why's the sea blue down there, is it the sky» Which is the best answer?

- **1.** Water soaks up red light first, so blue is what is left deeper down — **← Mova's choice** · **✓ the right answer** · no support
- **2.** Salt makes the water blue, and the deeper you go the more salt there is — no support
- **3.** It reflects the sky even 20 metres down — no support
- **4.** Fish paint the water blue — 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/8-the-ocean/t10/)

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### Test 11 · ★ · right ✓ {#t11}

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«sea's just water and fish, who cares about plankton» What is the clever answer?

- **1.** Plankton are just dirt in the water — score 11
- **2.** Plankton make the sea salty, which is why we cannot drink seawater — score 14
- **3.** Plankton feed the whole ocean and make about half our oxygen — **← Mova's choice** · **✓ the right answer** · score 18
- **4.** Plankton only feed whales — score 10

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**Why:** It took the question to ask who or what does it. It chose option 3 with score 18, against 14 for the next best. Its support: lesson 8, line 3: «A drop of seawater under the school microscope wriggles with plankton, tiny drifting algae and animals; they are the bottom of the ocean food chain, and the ti…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same action «make» (+5); the same doer «tiny algae» (+4); the same thing acted on «oxygen» (+3). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/8-the-ocean/t11/)

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### Exam question 1 · formal language · wrong ✗ {#e1}

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Which of the following statements most accurately characterises the sunlit zone of the ocean?

- **1.** The sunlit zone comprises the water beneath the polar ice — **← Mova's choice** · no support
- **2.** The sunlit zone comprises solely the intertidal shore — no support
- **3.** The sunlit zone comprises the deepest region of the ocean, wherein the glow of submarine volcanoes furnishes light for the growth of plankton — no support
- **4.** The sunlit zone comprises the uppermost two hundred metres of the ocean, wherein light suffices for the growth of plant-like plankton — **✓ 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/8-the-ocean/e1/)

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

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Identify the source of the luminescence emitted by the lure of the deep-sea anglerfish.

- **1.** Bacteria resident within the lure — **← Mova's choice** · **✓ the right answer** · no support
- **2.** Sunlight absorbed in shallow water — no support
- **3.** Reflection of the light of other fishes — no support
- **4.** An electrical organ within the jaw — 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/8-the-ocean/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 anatomy of the octopus.

- **1.** The octopus possesses two hearts and a shell — **← Mova's choice** · no support
- **2.** The octopus possesses three hearts, eight arms and blue blood, and lacks any bone — **✓ the right answer** · no support
- **3.** The octopus possesses a single heart and a skeleton of bone, by which its eight arms are supported — no support
- **4.** The octopus possesses ten arms and red blood — 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/8-the-ocean/e3/)

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### Exam question 4 · formal language · right ✓ {#e4}

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Ascertain the consequence for a sea turtle of the ingestion of a floating plastic bag.

- **1.** The plastic renders the turtle buoyant and swifter, whereby it more readily escapes from those predators which pursue it — no support
- **2.** The plastic is digested without consequence — no support
- **3.** The plastic augments the nourishment of the turtle — no support
- **4.** The plastic may obstruct the stomach and occasion a false sense of fullness, whereby the turtle starves — **← Mova's choice** · **✓ the right answer** · score 4

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**Why:** It took the question to ask which statement is true. It chose option 4 with score 4, the only option with support. Its support: lesson 8, line 15: «Sea turtles eat jellyfish and can mistake floating plastic bags for them; plastic can block the stomach so the turtle feels full and starves, and tiny micropla…», reached through the option's own match among the sentences about the question's things. What matched: the same action «starve» (+2); the same doer «turtle» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/8-the-ocean/e4/)

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- ← previous: [7. Antarctica: penguins, seals and the coldest plac…](https://md.mova.elamur.ai/free/en/school-run/biology/7-antarctica/)
- next →: [9. Coral reefs, rockpools and the seashore](https://md.mova.elamur.ai/free/en/school-run/biology/9-coral-reefs-rockpools-and-the-seashore/)
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