# Autumn leaves: answers and explanations

Cambridge IELTS 10, Test 3, Reading Passage 2

Source: Passage, questions and answer key from Cambridge IELTS 10, Test 3, Reading Passage 2. © Cambridge University Press & Assessment. Used for educational practice. Explanations and evidence notes are written by Testmigo.

## Answer key

| Q | Answer | Proof |
| --- | --- | --- |
| 14 | C | it is created by anthocyanins, water-soluble plant pigments reflecting the red to blue range of the visible spectrum. |
| 15 | B | So rather than maintaining the now redundant leaves throughout the winter, the tree saves its precious resources and discards them. |
| 16 | H | Even if you had never suspected that this is what was going on when leaves turn red, there are clues out there. |
| 17 | B | Summer leaves are green because they are full of chlorophyll, the molecule that captures sunlight and converts that energy into new building materials for the tree. |
| 18 | E | trees may produce vivid red colours to convince herbivorous insects that they are healthy and robust |
| 19 | sun | the leaves that are the reddest are those on the side of the tree which gets most sun. |
| 20 | upper | but the red is brighter on the upper side of the leaf. |
| 21 | dry | the best conditions for intense red colours are dry, sunny days and cool nights |
| 22 | north | trees such as maples usually get much redder the more north you travel in the northern hemisphere. |
| 23 | FALSE | or increase a leaf's tolerance to freezing. However there are problems with each of these theories |
| 24 | TRUE | It sounds paradoxical, because the idea behind this hypothesis is that the red pigment is made in autumn leaves to protect chlorophyll |
| 25 | NOT GIVEN | Do these trees have other means at their disposal to prevent overexposure to light in autumn? |
| 26 | B | This unmasking explains the autumn colours of yellow and orange |

## Why these answers are right

**14. C.** You need the paragraph that describes what makes leaves red. Paragraph C names anthocyanins as the source and describes them as water-soluble, sugar-based pigments that reflect the red to blue range of the spectrum. That description of the substance is in C.

**15. B.** This asks where the passage explains why trees lose leaves in autumn. Paragraph B says solar energy drops, so many trees stop photosynthesis until spring and discard the now useless leaves to save resources. That reason appears in B.

**16. H.** The item wants evidence that supports a theory about red leaves. Paragraph H lists clues backing the light screen idea: the reddest leaves face the sun, the upper side is brighter, and maples get redder further north. Those clues make H correct.

The why and the trap for questions 17 onwards are free with an account on the [answers page](https://testmigo.com/ielts/reading/autumn-leaves/answers).

[Practice Autumn leaves](https://testmigo.com/ielts/reading/autumn-leaves)