Plants deeper: leaves and sunlight, how a tree is made of air

Tests: 3 of 12 right · Exam: 0 of 4 right · Kind: plain · Understood: 12 of 16 · Run: 2026-10-18, commit f3c23ea72

Lesson 251 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 ✗

«my mate says trees grow by eating the dirt, that's why they need soil innit» What is right?

1. Yes, a tree is mostly soil packed tightly into wood by the roots — no support
2. No, a tree is made mostly of rainwater — ← Mova's choice · score 4
3. No, most of a tree is made from carbon dioxide from the air — ✓ the right answer · score 2
4. Yes, roots chew the dirt like teeth — score 1

Why: It took the question to ask why something happens (its cause). It chose option 2 with score 4, against 2 for the next best. Its support: lesson 251, line 3: «Here is the surprise: a huge oak does not eat soil to grow. Most of its wood is made from carbon taken out of the air, so in a real way a tree is built from ai…», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «tree» (+3); the same action «build» (+1). The right option, 3, scored 2. · the question and its options parsed, with trees and pragmatics

Test 2 · wrong ✗

What would happen if a leaf had all its stomata blocked with grease?

1. It would make food faster than before — score 3
2. Nothing at all, because leaves do not need any air to make their food — score 5
3. It could not take in carbon dioxide, so it could not make food — ✓ the right answer · score 4
4. It would turn bright red at once — ← Mova's choice · score 9

Why: It took the question to ask what happens next. It chose option 4 with score 9, against 5 for the next best. Its support: lesson 238, line 9: «Leafcutter ants do not eat leaves; they chew them to grow a fungus garden and eat the fungus, and they farmed long before people did.», reached through what followed the sentence the question matched. What matched: the same action «grow» (+6); the same doer «leaves» (+3). The right option, 3, scored 4. · the question and its options parsed, with trees and pragmatics

Test 3 · wrong ✗

You put one pondweed in the sun and one in a dark cupboard, both in water. Which makes more bubbles?

1. The one in the cupboard — ← Mova's choice · score 4
2. The one in the sun — ✓ the right answer · score 4
3. Neither, pondweed never makes bubbles — score -2
4. Both exactly the same — 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 172, line 9: «Some parrotfish make a see-through bubble of slime to sleep in at night, and they make a new bubble every night.», reached through the remembered sentence the question matched. What matched: the same action «make» (+2); the same thing acted on «see through bubble» (+2). The right option, 2, scored 4. · the question and its options parsed, with trees and pragmatics

Test 4 · wrong ✗

Count them: 3 sunflowers each have 1 flower head and 12 leaves. How many leaves and heads altogether?

1. 15 leaves and 1 head — ← Mova's choice · no support
2. 12 leaves and 3 heads — no support
3. 36 leaves and 3 heads — ✓ the right answer · no support
4. 36 leaves and 36 heads — 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 5 · wrong ✗

«autumn's here so the tree paints its leaves yellow, cool» What is a better way to say it?

1. The yellow comes from the sun burning the leaves — no support
2. The frost colours the leaves overnight — no support
3. The tree makes yellow paint out of the soil and sends it up — ← Mova's choice · score 6
4. The yellow was there all summer, hidden under the green — ✓ the right answer · no support

Why: It took the question to ask which statement is true. It chose option 3 with score 6, the only option with support. Its support: lesson 251, line 8: «In autumn many trees stop making green chlorophyll and take it back, so yellow and orange colours, there all along, show through; reds are made fresh, brightes…», reached through the option's own match among the sentences about the question's things. What matched: the same action «make» (+4); the same doer «many trees» (+2). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 6 · right ✓

In a cartoon, Jerry hides in a pot plant and the plant gives him a sandwich it made from soil. What is true of real plants?

1. They make sugar for themselves from air, water and light, not sandwiches from soil — ← Mova's choice · ✓ the right answer · score 8
2. They really cook food from soil for the animals that live in the forest — score 7
3. They make food only at night in the dark — score 5
4. They do not need any food at all — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 8, against 7 for the next best. Its support: lesson 56, line 5: «Cartoons show plants eating soil with roots like spoons, and carnivorous plants swallowing people; real plants make their own food from light, air and water, a…», reached through the option's own match among the sentences about the question's things. What matched: the same action «make» (+4); the same place «light» (+4). · the question and its options parsed, with trees and pragmatics

Test 7 · right ✓

Which is true about the oxygen you breathe?

1. It was given off by plants and algae as a leftover of making food — ← Mova's choice · ✓ the right answer · score 5
2. It is made by clouds when it rains — score 5
3. It was always in the air since the Earth began and is never made by anything — no support
4. It comes out of the ground from volcanoes — no support

Why: It took the question to ask which statement is true. It chose option 1 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 60, line 4: «Most of a tree is made from the air: it takes in carbon dioxide, keeps the carbon in its wood and gives out oxygen, which is why old forests matter so much for…», reached through the option's own match among the sentences about the question's things. What matched: the same action «give out» (+4); the same thing acted on «oxygen» (+1). · the question and its options parsed, with trees and pragmatics

Test 8 · wrong ✗

A gardener keeps a plant with white and green leaves next to an all-green one in the same pot size and light. What will most likely happen?

1. The white and green one grows faster — no support
2. They grow at exactly the same speed — ← Mova's choice · score 6
3. The white parts turn green by next week — score 4
4. The all-green one grows faster — ✓ the right answer · no support

Why: It took the question to ask which statement is true. It chose option 2 with score 6, against 4 for the next best. Its support: lesson 251, line 5: «Leaves use sunlight to turn water and carbon dioxide from the air into sugar for food; this is called photosynthesis.», reached through the option's own match among the sentences about the question's things. What matched: the same action «turn» (+4); the same doer «leaves» (+2). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 9 · right ✓

«poked the mimosa like 50 times and it got lazy and stopped closing, broken?» What is the likely answer?

1. Yes, it is dying and must be thrown away — no support
2. Not broken: mimosas touched again and again without harm can stop folding — ← Mova's choice · ✓ the right answer · score -2
3. No, it is just pretending to be asleep — no support
4. Yes, the leaves have run out of water forever and will never move again — no support

Why: It took the question to ask which statement is true. It chose option 2 with score -2, the only option with support. Its support: lesson 251, line 13: «The sensitive plant, mimosa, folds its leaflets within seconds when touched, by moving water out of cells at the base of each leaf.», reached through the remembered sentence the question matched. What matched: the same action «touch» (+1). Against it: the same doer «sensitive plant» (-3). · the question and its options parsed, with trees and pragmatics

Test 10 · wrong ✗

Why would a broad oak leaf be a problem in a frozen winter?

1. It would catch too much sunlight in winter — score 2
2. It would make too much food in the snow — ← Mova's choice · score 4
3. It would freeze into a solid block of ice and explode — no support
4. It would lose water the roots cannot replace from frozen ground — ✓ the right answer · score 2

Why: It took the question to ask why something happens (its cause). It chose option 2 with score 4, against 2 for the next best. Its support: lesson 1, line 18: «Koalas eat almost only eucalyptus leaves, which are tough, low in energy and slightly poisonous and need special gut bacteria to digest, so they rest or sleep…», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «eucalyptus leaves» (+3); the same doer «eucalyptus leaves» (+1). The right option, 4, scored 2. · the question and its options parsed, with trees and pragmatics

Test 11 · wrong ✗

In a game, a plant character drinks sunlight like juice from a glass. What is closer to the truth?

1. Leaves really store the sunlight like juice inside them, to drink later — ← Mova's choice · score 1
2. Only flowers use light, never leaves — no support
3. Plants do not use sunlight at all — score 0
4. Sunlight is the energy that powers a leaf's food making, not something it drinks — ✓ the right answer · no support

Why: It took the question to ask which statement is true. It chose option 1 with score 1, against 0 for the next best. Its support: lesson 251, line 5: «Leaves use sunlight to turn water and carbon dioxide from the air into sugar for food; this is called photosynthesis.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «leaves» (+2); the same thing acted on «sunlight» (+1). Against it: a different action (counts against) (-2). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 12 · wrong ✗

«so if half our oxygen is from the sea, we breathe thanks to seaweed and tiny algae?» What is the answer?

1. Yes, a large part comes from tiny algae and other sea life — ✓ the right answer · no support
2. No, all oxygen comes from rainforests — no support
3. Only from fish breathing out bubbles — no support
4. No, the sea takes oxygen away and never makes it — ← Mova's choice · score 3

Why: It took the question to ask which statement is true. It chose option 4 with score 3, the only option with support. Its support: lesson 203, line 6: «Fish take oxygen from water through their gills, and a filter, moving water and air bubbles help mix more oxygen into the water.», reached through the option's own match among the sentences about the question's things. What matched: the same action «take» (+4); the same thing acted on «oxygen» (+1). Against it: a different doer (counts against) (-2). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · wrong ✗

Identify the principal source of the carbon which constitutes the greater part of the dry mass of a tree.

1. Organic matter derived from fallen leaves — no support
2. Mineral matter extracted from the soil by the roots — no support
3. Carbon dioxide absorbed from the atmosphere — ✓ the right answer · no support
4. Water drawn up through the roots — ← Mova's choice · score 3

Why: It took the question to ask which statement is true. It chose option 4 with score 3, the only option with support. Its support: lesson 178, line 1: «Most trees die if you pour salty sea water on their roots, but mangroves grow with their feet in it, along warm tropical coasts where the tide comes in and out…», reached through the option's own match among the sentences about the question's things. What matched: the same place «roots» (+4); the same thing acted on «salty sea water» (+1). Against it: a different action (counts against) (-2). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · wrong ✗

Select the response consistent with the established facts concerning the colouration of deciduous leaves in autumn.

1. The colouration is produced by solar scorching of the leaf during the shortening days of autumn — ← Mova's choice · no support
2. Yellow and orange pigments, present throughout, are revealed when chlorophyll is withdrawn — ✓ the right answer · no support
3. Yellow pigment is manufactured afresh in response to frost — no support
4. The colouration results from rust deposited by rainfall — 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 · wrong ✗

State the function of the minute apertures, hereinafter referred to as stomata, situated upon the underside of a leaf.

1. The secretion of nectar for pollinating insects — ← Mova's choice · no support
2. The admission of air and the release of water vapour — ✓ the right answer · no support
3. The absorption of mineral salts from rainwater — no support
4. The anchorage of the leaf to the stem — 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 · wrong ✗

It is given that a submerged aquatic plant, exposed to sunlight, emits small bubbles. Ascertain the identity of the gas so emitted.

1. Water vapour — ← Mova's choice · no support
2. Carbon dioxide — no support
3. Oxygen — ✓ the right answer · no support
4. Nitrogen — 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

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/biology/251-plants-deeper-leaves-and-sunlight-how-a-tree-is-made-of-air/