The aquarium: jellyfish, octopuses, sea stars and the deep sea

Tests: 7 of 12 right · Exam: 2 of 4 right · Kind: ★ · Understood: 9 of 16 · Run: 2026-10-18, commit f3c23ea72

Lesson 92 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 · ★ · wrong ✗

two octopuses in the tank, how many hearts is that

1. 4 — ← Mova's choice · no support
2. 16 — no support
3. 6 — ✓ the right answer · no support
4. 2 — 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 2 · ★ · wrong ✗

An octopus and a sea star share a rock pool. The sea star has five arms. How many arms in all?

1. 10 — ← Mova's choice · no support
2. 18 — no support
3. 13 — ✓ the right answer · no support
4. 15 — 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 ✗

Squidward is drawn with six legs. How many arms would a real octopus need to add?

1. None — ← Mova's choice · no support
2. Four — no support
3. Two — ✓ the right answer · no support
4. Six — 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 4 · ★ · right ✓

my nan says jellyfish are just fish with no bones, innit?

1. Yes, they are fish that lost their bones long ago — score 6
2. Yes, but only the big ones — no support
3. No, they are a kind of seaweed — no support
4. No, they are not fish at all but cousins of corals — ← Mova's choice · ✓ the right answer · score 8

Why: It took the question to ask which statement is true. It chose option 4 with score 8, against 6 for the next best. Its support: lesson 92, line 1: «Some of the strangest animals in the aquarium are not fish at all: jellyfish, octopuses, cuttlefish, sea stars and lobsters have no backbone, which makes them…», reached through the option's own match among the sentences about the question's things. What matched: the same place «all» (+3); the same light verb (be, have, do, get, go) (+3); the same thing acted on «fish» (+2). · the question and its options parsed, with trees and pragmatics

Test 5 · ★ · right ✓

What would happen if an octopus tank had a loose lid?

1. The octopus might squeeze out and wander off — ← Mova's choice · ✓ the right answer · no support
2. The octopus would hide its ink in the gap — no support
3. Nothing, because octopuses can never leave the water — no support
4. The other fish would swim out — 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 6 · ★ · wrong ✗

The keeper says a jellyfish is "immortal". What is the best correction?

1. It dies after one day — ← Mova's choice · no support
2. It can turn young again but can still be eaten or get ill — ✓ the right answer · no support
3. It lives exactly a hundred years — no support
4. It really can never die in any way, not even if eaten — 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 7 · ★ · right ✓

In a cartoon a sea star wears glasses and reads books in its brain. What is true of a real sea star?

1. It has two eyes and a big brain — score 6
2. It has no brain and has an eye spot at each arm tip — ← Mova's choice · ✓ the right answer · score 9
3. It has a little brain in each arm but no eyes at all — score 6
4. It sees only with glasses — no support

Why: It took the question to ask which statement is true. It chose option 2 with score 9, against 6 for the next best. Its support: lesson 92, line 15: «A sea star has no brain, can regrow a lost arm, and has a simple eye spot at the tip of each arm that senses light.», reached through the option's own match among the sentences about the question's things. What matched: the same place «tip» (+3); the same light verb (be, have, do, get, go) (+3); the same thing acted on «simple eye spot» (+2); the same doer «sea star» (+1). · the question and its options parsed, with trees and pragmatics

Test 8 · ★ · right ✓

SpongeBob is a square yellow kitchen sponge. What is a real sea sponge?

1. A mineral made by the sea — no support
2. A fish that soaks up water — score 3
3. A soft green plant that grows on rocks in the sea — no support
4. A simple animal with no brain that filters water — ← Mova's choice · ✓ the right answer · score 5

Why: It took the question to ask which statement is true. It chose option 4 with score 5, against 3 for the next best. Its support: lesson 92, line 18: «In SpongeBob, Patrick is a sea star and Squidward is named like a squid, but his creator said he is an octopus, drawn with six legs instead of eight arms; a re…», reached through the same lesson line as the sentence the question matched. What matched: the same action «filter» (+4); the same thing acted on «water» (+1). · the question and its options parsed, with trees and pragmatics

Test 9 · ★ · right ✓

A cartoon lobster is bright red, swimming in the sea. What would you fix?

1. Live lobsters are greenish brown; red is the cooked colour — ← Mova's choice · ✓ the right answer · score 6
2. Lobsters are always bright blue while they are in the sea — score 5
3. Lobsters are white until they grow up — no support
4. Nothing, lobsters are red alive — no support

Why: It took the question to ask what it is done to. It chose option 1 with score 6, against 5 for the next best. Its support: lesson 92, line 16: «Live lobsters are usually greenish brown and turn red only when cooked, because heat breaks down a protein that hides the red colour; a rare blue lobster, by a…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «live lobsters» (+4); the same property (+1); the same light verb (be, have, do, get, go) (+1). · the question and its options parsed, with trees and pragmatics

Test 10 · ★ · right ✓

Cuttlefish seem to be colour-blind. Which is true?

1. They cannot change colour at all, so they just stay grey — score 6
2. They only turn black and white — no support
3. They still match their backgrounds very well — ← Mova's choice · ✓ the right answer · score 12
4. They copy the colours of other fish — score 4

Why: It took the question to ask which statement is true. It chose option 3 with score 12, against 6 for the next best. Its support: lesson 92, line 13: «Cuttlefish change colour and pattern in less than a second using millions of tiny colour sacs in the skin; they seem to be colour-blind, yet they still match t…», reached through the same lesson line as the sentence the question matched. What matched: the same action «match» (+4); the same doer «cuttlefish» (+4); the same property (+3); the same thing acted on «backgrounds» (+1). · the question and its options parsed, with trees and pragmatics

Test 11 · ★ · right ✓

Why would light be so useful in the deep sea?

1. No sunlight reaches there, so it is the only way to be seen — ← Mova's choice · ✓ the right answer · no support
2. It frightens away the sunlight — no support
3. It warms the freezing water — no support
4. It makes green plants grow all over the dark sea floor — 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 12 · ★ · wrong ✗

A sea star loses an arm to a crab. What happens next?

1. The crab grows into a sea star — ← Mova's choice · score 2
2. It can grow a new arm — ✓ the right answer · score 2
3. It walks with four arms forever — score 2
4. It dies at once from the wound — no support

Why: It took the question to ask what happens next. It chose option 1 with score 2, tied with another option at 2 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 9, line 15: «Crabs walk sideways because their leg joints bend best that way, though many can also walk slowly forwards, have 10 legs counting the 2 claws, and grow by moul…», reached through the option's own match among the sentences about the question's things. What matched: the same action «grow» (+1); the same doer «crabs» (+1). The right option, 2, scored 2. · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · wrong ✗

Which of the following statements most accurately characterises the jellyfish?

1. It is a marine plant that pulses with the tide — score 9
2. It is an invertebrate allied to corals, devoid of brain, heart and bones — ✓ the right answer · score 9
3. It is the juvenile form of the octopus — ← Mova's choice · score 12
4. It is a boneless fish possessing gills, fins and a simple brain — score 10

Why: It took the question to ask who or what does it. It chose option 3 with score 12, against 10 for the next best. Its support: lesson 92, line 6: «Jellyfish have no brain, heart or bones, are about 95 per cent water, and swim by squeezing their bell; they live in round tanks so they are not trapped in cor…», reached through a sentence linked to the one the question matched. What matched: it fills the role the question asks for (+5); the same doer «jellyfish» (+4); the same circumstance (+3). The right option, 2, scored 9. · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · wrong ✗

Ascertain the aggregate number of hearts possessed by three octopuses.

1. Twenty-four — ← Mova's choice · no support
2. Six — no support
3. Three — no support
4. Nine — ✓ 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 3 · formal language · right ✓

Identify the principal reason for which octopus blood is blue in colour.

1. Its body temperature is exceedingly low — no support
2. Its ink is dissolved within the blood — no support
3. The animal ingests large quantities of seawater, which tints the blood — no support
4. Oxygen is carried by a substance containing copper rather than iron — ← Mova's choice · ✓ the right answer · score 5

Why: It took the question to ask which statement is true. It chose option 4 with score 5, the only option with support. Its support: lesson 92, line 11: «An octopus has three hearts, two for the gills and one for the body, and its blood is blue because it uses copper instead of iron to carry oxygen.», reached through the same lesson line as the sentence the question matched. What matched: the same action «carry» (+4); the same thing acted on «oxygen» (+1). · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · right ✓

Select the response consistent with the established facts concerning the colour of the lobster.

1. It is red in life and turns brown upon being cooked — no support
2. It is greenish brown in life and turns red upon cooking — ← Mova's choice · ✓ the right answer · score 7
3. It is invariably blue throughout its life — no support
4. It is white in life and turns red with age — score 7

Why: It took the question to ask which statement is true. It chose option 2 with score 7, tied with another option at 7 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 92, line 16: «Live lobsters are usually greenish brown and turn red only when cooked, because heat breaks down a protein that hides the red colour; a rare blue lobster, by a…», reached through the same lesson line as the sentence the question matched. What matched: the same action «turn» (+4); the same property (+3). · the question and its options parsed, with trees and pragmatics

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/biology/92-the-aquarium-jellyfish-octopuses-sea-stars-and-the-deep-sea/