Cambridge Lower Secondary Science ENGLISH LANGUAGE SKILLS WORKBOOK 8 Sample

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Cambridge Lower Secondary

Science

ENGLISH LANGUAGE SKILLS WORKBOOK 8

SA M

Mary Jones & Sally Burbeary

Second edition

Digital access

Original material © Cambridge University Press 2021

PL E

Cambridge Lower Secondary

Science

ENGLISH LANGUAGE SKILLS WORKBOOK 8

SA

M

Mary Jones & Sally Burbeary

Original material © Cambridge University Press 2021

University Printing House, Cambridge CB2 8BS, United Kingdom One Liberty Plaza, 20th Floor, New York, NY 10006, USA 477 Williamstown Road, Port Melbourne, VIC 3207, Australia 314–321, 3rd Floor, Plot 3, Splendor Forum, Jasola District Centre, New Delhi – 110025, India 103 Penang Road, #05–06/07, Visioncrest Commercial, Singapore 238467 Cambridge University Press is part of the University of Cambridge.

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It furthers the University’s mission by disseminating knowledge in the pursuit of education, learning and research at the highest international levels of excellence. www.cambridge.org Information on this title: www.cambridge.org/9781108742931 © Cambridge University Press 2021

This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press.

First published 2014 Second edition 2021

20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Printed in Poland by Opolgraf

A catalogue record for this publication is available from the British Library ISBN 978-1-108-79905-8 Paperback with Digital Access (1 year)

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Additional resources for this publication at www.cambridge.org/delange

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Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. Information regarding prices, travel timetables, and other factual information given in this work is correct at the time of first printing but Cambridge University Press does not guarantee the accuracy of such information thereafter.

NOTICE TO TEACHERS IN THE UK It is illegal to reproduce any part of this work in material form (including photocopying and electronic storage) except under the following circumstances: (i) where you are abiding by a licence granted to your school or institution by the Copyright Licensing Agency; (ii) where no such licence exists, or where you wish to exceed the terms of a licence, and you have gained the written permission of Cambridge University Press (iii) where you are allowed to reproduce without permission under the provisions of Chapter 3 of the Copyright, Designs and Patents Act 1988, which covers, for example, the reproduction of short passages within certain types of educational anthology and reproduction for the purposes of setting examination questions.

Original material © Cambridge University Press 2021

Contents

Contents English skills and support

16 19 21 23 26

28 31 33 35

1.1 1.2 1.3 1.4 1.5

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The human respiratory system Gas exchange Breathing Respiration Blood

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1 Respiration

1 2 3 6 6 7 10 12 13 14 15

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Connecting words Command words Comparative and superlative adjectives The language of science experiments Making predictions Modal verbs Prepositions Phrasal verbs Graphs Singular and plural Active and passive

2 Properties of materials Dissolving 2.2 Solutions and solubility 2.3 Planning a solubility investigation 2.4 Paper chromatography 2.1

3 Forces and energy Forces and motion 3.2 Speed 3.3 Describing movement

38 41 43

3.1

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Contents

Turning forces 3.5 Pressure between solids 3.6 Pressure in liquids and gases 3.7 Particles on the move 3.4

46 49 51 54

4 Ecosystems The Sonoran Desert 4.2 Different ecosystems 4.3 Intruders in an ecosystem 4.4 Bioaccumulation

56 57 60 62

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4.1

5 Materials and cycles on Earth 5.1 5.2 5.3 5.4 5.5

The structure of the atom Purity Weather and climate Climate and ice ages Atmosphere and climate

6.1 6.2 6.3

Reflection Refraction Making rainbows Colours of light Galaxies Rocks in space

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6.4

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6 Light

6.5 6.6

64 66 68 70 72

74 78 80 82 84 86

7 Diet and growth

Nutrients 7.2 A balanced diet 7.3 Growth, development and health 7.4 Moving the body 7.1

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88 90 92 94

Contents

8 Chemical reactions 8.2 8.3 8.4 8.5

Exothermic reactions Endothermic reactions Reactions of metals with oxygen Reactions of metals with water Reactions of metals with dilute acids

9 Magnetism

96 98 101 103 105

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8.1

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Magnetic fields 107 9.2 The Earth as a giant magnet 109 9.3 Electromagnets 112 9.4 Investigating electromagnets 114 9.1

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How to use this book

How to use this book This workbook will help you to understand and use the English that is involved while learning science.

It will help you to: understand what you read in your science books, and what your teacher tells you during the lessons

•

talk to other learners during your science lessons in English, using the correct vocabulary

•

understand questions that you are asked by your teacher or in a test

•

speak or write answers to science questions that say clearly what you mean.

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•

English skills and support

Lines

straight

A straight line can be in any direction.

horizontal

A straight line that goes across from side to side.

—

vertical

A straight line that goes from top to bottom.

|

curved line

A curved line is not straight.

—\/

Singular and plural

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This workbook contains an English skills and support section. This contains information about English grammar and vocabulary to help you with science.

You can use the reference section at any time you need help with English while studying science.

Singular means one thing.

Plural means two or more things.

A verb describes an action, state or event.

The verb ‘to be’ Use the verb is with single and uncountable nouns. For example: A heart is an organ.

Use the verb are with plural nouns. For example: There are many organs in the human body.

Other verbs

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Who or what

This workbook provides questions for you to practise what you have learnt in class. There is a topic to match each topic in your Learner’s Book and exercises in each topic. You can use the English skills and support section to help you as you complete the exercises.

Verbs

I, you, we, they

look, explain, change, transfer, use

it, she, he

looks, explains, changes, transfers, uses

If you startand a sentence 3 Forces energywith It, She or He, you must put an ‘s’ on the end of the verb.

It is easy to get confused with the letter ‘s’ at the end of English words.

Remember: an ‘s’ on the end of a noun usually makes it plural (for example: 1 vein,

2 veins).

Exercise 2 Writing two or more sentences Remember: an ‘s’ on the end of a verb makes it agree with it, she, he (for example: in an answer it reflects, she experiments).

Uncountable nouns describe things that are impossible to count, for example water, Sometimes, a question needs a slightly longer usual. things, and sand and oxygen.

Uncountable nouns behave like it,answer she, hethan or singular thisan exercise, yourthese own words. sentences to answer weInadd ‘s’ to theyou endpractise of verbswriting that follow ‘Explain’ questions.

Besome careful, there are some irregular plural nouns, for example: 1 cactus, 2 cacti and 1 species, 2 species.

Look at Command words in the English skills and support section for information about command words.

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Write at least two sentences to answer each of these three questions. Make sure that your second sentence has some new information in it and is not just the first sentence written in a different way. a

Explain why it is easier to cut an apple with a sharp knife than a blunt knife. ………………………………………………………………………………………. ………………………………………………………………………………………. ………………………………………………………………………………………. ……………………………………………………………………………………….

b

Explain what you need to know in order to calculate the pressure that an object is producing on the floor. ………………………………………………………………………………………. ………………………………………………………………………………………. ………………………………………………………………………………………. ……………………………………………………………………………………….

c

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Explain why the large feet of a camel help to stop it sinking into sand. ………………………………………………………………………………………. ……………………………………………………………………………………….

……………………………………………………………………………………….

Original material © Cambridge University Press 2021 ……………………………………………………………………………………….

English skills and support

English skills and support This book is to help you with English skills when you are studying science. The English skills and support section gives you information about important topics in English that you will use in science. You can use this section at any time you need help with English while studying science.

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In this English reference section, there is information about English grammar and vocabulary to help you with science.

Many different grammatical words will be explained in the English language reference section.

Connecting words

Connecting words help you to join two pieces of information together in different ways.

In science, we often need to talk about more than one thing. We can join two ideas together with connecting words, for example: and, but, because, so. These are called connectives. Connectives are like glue – they stick two ideas together.

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There are many connecting words in English and they do different things in sentences.

Connective

What it is used for

and

connecting two positives together

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or

connecting two negatives together

but

connecting a positive and a negative together

because

giving a reason why

so

giving the result of a situation

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English skills and support

Here are some examples. positive

+

positive

and Roots are usually underground

and +

but

The roots underground continue to live

but

fact or situation

because

negative

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positive

anchor the plant in the ground.

Plants can absorb minerals from soil

because

why

they have roots.

fact or situation

+

result

Plants have roots

so

they can absorb minerals from the soil.

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so

+

the parts of the plant above ground might die in harsh conditions.

Command words

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Science questions often start with ‘Name’, ‘State’, ‘Describe’ or ‘Explain’.

You need to know how to answer these questions correctly.

Command words

Answer

Name

Give the name of the person, object or animal.

State

Give brief information.

Describe

Say what happens.

Explain

Say why something happens.

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English skills and support

For example: Question: Name a compound.

Answer: Water.

Question: State the features of a compound.

Answer: A compound has more than one type of atom, which are joined tightly together.

Question: Describe what happens when iron is heated with sulfur.

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Answer: The iron and sulfur react together to form a new substance. The iron atoms bond with the sulfur atoms to make iron sulfide.

Question: Explain why metals oxidise.

Answer: Many metals oxidise because of a chemical reaction of the metal surface with the oxygen present in the air.

Comparative and superlative adjectives This section helps you to do two things.

It helps you to talk about:

the differences between things (comparative adjectives)

•

an object expressing the extreme quality of that thing in a group of objects (superlative adjectives).

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•

Scientists often want to compare two or more things.

For example: feathers and leaves are lighter than stones and rocks.

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Comparative adjectives

Comparative adjectives are formed by adding -er to shorter adjectives and more before longer adjectives. The number of syllables in a word helps you to choose whether to use -er or more. A syllable is the number of sounds in a word. For example, ‘gas’ has one syllable, ‘copper’ has two syllables and ‘magnetic’ has three syllables. Be careful with the spelling rules when forming comparative adjectives.

Notice that ‘than’ is used after the comparative adjective.

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English skills and support

Form

Example sentence

tall + er

An adult is taller than a young child.

fast + er

large + r One syllable adjectives

big + er

A molecule is larger than an atom.

Jupiter is bigger than Mars.

Venus is hotter than Neptune.

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hot + er

The particles in a solid are closer together than in a gas.

For most adjectives, just add -er to the end.

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close + r

A leopard runs faster than an antelope.

Spelling notes

A brick is heavier than a feather.

heavy + er

healthy + er

Fruit is healthier than chocolate.

Two syllable adjectives not ending in -y

more + common

At night bats are more common than most birds.

more + active

Bats are more active at night than most birds.

Long adjectives of three or more syllables

more + reactive

Magnesium is more reactive than nickel.

more + addictive

Nicotine is more addictive than caffeine.

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Two syllable adjectives ending in -y

Adjectives that end in -e, just add -r to the end.

If the last three letters of the adjective end in consonant, vowel, consonant, double the last letter before adding -er.

Remember vowels are A, E, I, O, U and consonants are all of the remaining letters of the alphabet. There are exceptions to the rule, for example, words ending in ‘w’, such as: low and slow become lower and slower.

For adjectives ending in ‘y’, change the ‘y’ to ‘i’.

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English skills and support

You can also compare things that are the same: for example, ‘Lemon juice is as acidic as vinegar.’

You can also show how one thing affects another.

Here are some examples.

•

The greater the amplitude of the sound wave, the louder the sound.

•

The more you exercise, the harder your muscles work.

Superlative adjectives

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Be careful when using ‘bigger’ or ‘larger’ and ‘greater.’ Generally, ‘bigger’ and ‘larger’ mean the same and are used to talk about the physical size of objects, animals and people. ‘Greater’ has a similar meaning, but it is also used to talk about the value of something, for example ‘the force is greater’.

In science, you may also want to say what is at the top or the bottom of a range of things. Superlative adjectives say what is at the top and the bottom of a range.

Notice that you always put ‘the’ before superlative adjectives Remember, you make a superlative adjective by: •

adding -est to the end of short adjectives (hard, cold, large, small)

For example: Diamonds are the hardest natural substance on Earth.

•

or adding the most before longer adjectives (reactive, conductive, reflective)

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For example: The most conductive element is silver.

Be careful! Words of two syllables (sounds) can use both -est and the most.

For two-syllable adjectives ending in ‘y’ change ‘y’ to ‘i’ and add -est (heavy – the heaviest).

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For adjectives of two or more syllables not ending in ‘y’, add the most before the adjective (active – the most active; reactive – the most reactive).

Be aware that some adjectives are irregular. This means they don’t follow the usual rules.

Irregular adjectives

Adjective

Comparative

Superlative

far

further

the furthest

few

fewer

the fewest

little

less

the least

many

more

the most

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English skills and support

The language of science experiments When doing scientific experiments, you often use the words observations, results, conclusions and explanation. You need to be clear about the differences between them.

Something that you notice, using your senses.

result

What you find out in your experiment: results are often numerical data.

conclusion

Your decision about what your results mean: a conclusion is often an answer to the question your experiment investigated, or a decision about whether your hypothesis is supported or disproved.

explanation

Why or how you reached this conclusion: you use your scientific understanding to give reasons.

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observation

Making predictions

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A prediction is a guess about what you expect to happen in the future, based on your observations.

You can use will and might to make predictions.

Will and might are followed by the infinitive of the verb without “to”, for example:

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It will snow this winter.

It might snow this winter.

Will shows that we are very sure: A plant that has light and water will grow well.

I think the universal indicator will turn red when I dip it in lemon juice.

Might shows we are less sure:

Eating too much red meat might cause heart disease.

It is raining and the sun is coming out. We might see a rainbow.

Will and might are the same for all people and objects, for example: I, you, he, she, it, they, we will predict the result accurately.

I, you, he, she, it, they, we might not get an accurate result.

It is common to use I think…, I don’t think… and Do you think…? to introduce predictions when we speak.

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English skills and support

For example: I think water will turn to ice at zero degrees Celsius.

I think silver might melt at a lower temperature than iron.

I don’t think aluminium will oxidise in water.

Do you think this experiment will work well?

Do you think this experiment might fail?

Modal verbs

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Note: we cannot use might with I don’t think.

Modal verbs are a special type of verb that go before normal verbs in a sentence. Modal verbs show that things are certain, probable, possible or impossible.

There are many modal verbs and each one has a different function or functions.

Here are some of the most common modal verbs.

This modal verb shows: •

an ability to do something

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can

SA

•

that something is possible.

Sound can travel through air. (Sound has the ability to travel through air.)

Water can be a solid, liquid or a gas. (It is possible for water to be a solid, liquid or a gas.)

cannot (can’t)

This means the opposite. It means: •

you are not able to do something

•

that something is not possible.

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English skills and support

Sound can’t travel through a vacuum. (Sound does not have the ability to travel through a vacuum.)

When a solution is saturated, the solvent can’t dissolve any more solute. (It is not possible to dissolve any more solute.)

might

This means there is a chance it could happen.

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safety spectacles

water

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tongs

evaporating basin

pipe clay triangle tripod

bunsen burner

When I do this experiment, there might be a chemical reaction. (There is a chance that there will be a chemical reaction.)

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English skills and support

This means the opposite. It means that perhaps it won’t happen.

might not

You might not get the result you predicted. (Perhaps the result will be different from what you expected.)

This is a strong modal verb and it means that something is essential to do (you can’t say no).

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must

You must wear goggles when mixing chemicals. (It is essential to avoid accidents.) must not (mustn’t)

This means the opposite. It means that it is essential not to do something.

You must not spill chemicals on your skin. (It is essential not to do this as it is very dangerous.)

should

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Use this modal verb to: •

give advice

•

show something you expect will happen.

SA

You should eat a balanced diet to be healthy. (I advise you to do this.)

Water should freeze when the temperature is below 0 °C. (You expect water to freeze when the temperature is below 0 °C.)

should not (shouldn’t)

This means the opposite. It means: •

advise not to do something

•

something that you don’t expect to happen.

You shouldn’t eat too much fatty food. (I advise you not to do this.)

Gold shouldn’t oxidise in air. (You don’t expect gold to oxidise in air.)

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English skills and support

Prepositions Prepositions are usually short words, for example: in, on, at, by, from, to, out. Each preposition has a particular meaning and it is important you know how they are used in sentences. There are other prepositions in English that can be used in different ways to the examples included here, and the exercises in this workbook will help you learn about some of those other uses.

Prepositions – time

in

on

Examples

duration of time

I will check the temperature in five minutes (in the future).

I will check the plant growth in three days (in the future).

I wake up early in the morning.

I often go on holiday in the summer.

a precise time

The sun sets at 6 o’clock.

I am learning science at the moment.

Nocturnal animals hunt at night.

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at

Usage

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In, at, on are common prepositions. You can use these prepositions to talk about time or place.

I have football practice on Wednesday.

My birthday is on 10th September.

Usage

Examples

SA

Prepositions – place

days and dates

in

in a space or area, or inside something

I live in a town/country.

I plant seeds in a garden.

Fish live in the water.

My lessons are in a school. (Inside the building.)

at

a point or particular place

I write my notes at my desk.

I write my name at the top.

I meet my friends at school. (At this place.)

a surface

My book is on the table.

Wood floats on water.

My chair is on the floor.

on

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English skills and support

Prepositions

Usage

Examples I run through the tunnel.

through

through and along are similar; through means moving from one side to the other in a three dimensional object

Water flows through the pipe.

Oxygen passes through the lungs.

I can see through the hole.

down

moving to a lower level

up

moving to a higher level

between

in or into an area that separates two people, places or objects

Put a light bulb between a battery and a switch to make a simple circuit.

comes from a source

Scientists extract metal ore from rocks.

Roughage is another name for fibre.

for

intended for something or a purpose

of

relationship between things

Gold is a type of metal.

how something is done

You can make tea by diffusing tea leaf particles in hot water. (This is how you make tea.)

the cause of something

In smokers, cancer is caused by tar in cigarettes.

(Tar is the cause of cancer.)

by

The ball travels along the ground.

Marcus measured Zara’s heart rate as she walked quickly along the road.

A rock sinks down to the bottom of a river.

Gravity: what goes up, must come down.

Wood floats up to the surface of a river.

Mercury rises in a thermometer as the temperature goes up.

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SA

from

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along

move in line with something (the distance or length travelled is the main idea)

The Earth is between Venus and Mars.

Arteries carry blood away from the heart.

An ammeter is used for measuring electrical current.

The heart is part of the circulatory system.

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English skills and support

Phrasal verbs Phrasal verbs are made up of a verb followed by a preposition.

Prepositions are usually short words, for example: in, on, at, by, from, up. Phrasal verbs are used a lot in English and science. Each phrasal verb can have many meanings, but these are common uses of phrasal verbs with ‘out’ in science.

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Verbs used without a preposition have one meaning, but when you add a preposition to the verb it has a different meaning. Carry and carry out are used a lot in science, so it is important to know the difference.

Verb

Preposition

Meaning

Example

carry

out

to do an activity

I carried out the experiment on my own.

give

out

emit

Some chemical reactions give out heat.

to open, arrange or place something over a large area

When potassium manganate (VII) is placed in water, the particles spread out and mix with the water particles.

out

discover

I want to find out if paper aluminium is magnetic.

out

use every last available part or piece/having nothing left

The engine will stop if it runs out of fuel.

confuse

Don’t mix up the meaning of reflection and refraction.

create

The colour magenta is made up of red and blue.

SA

find

out

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spread

run

mix

make

up

up

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English skills and support

‘To’ is a very common preposition and is used in many different ways. Here are some verbs that are followed by ‘to’.

Verb

Preposition

Example Add hydrogen to oxygen and it makes water.

to (something or someone)

introduce

to (something or someone)

Graphs

The muscles in your forearm cross the elbow and attach to the humerus.

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join, attach, add

In a battery, join the cathode to the positive terminal, and the anode to the negative terminal.

The grey squirrel was introduced to the UK in the 1890s.

Arun, I would like to introduce you to Zara.

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You need to know the names of the different parts of a graph.

500 400 300

SA vertical axis or y-axis

Distance travelled in metres

200 100 0

0

20 40 Time in seconds

60

horizontal axis or x-axis

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English skills and support

Lines A straight line can be in any direction.

—\/

horizontal

A straight line that goes across from side to side.

—

vertical

A straight line that goes from top to bottom.

|

curved line

A curved line is not straight.

Singular and plural

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straight

Singular means one thing.

Plural means two or more things.

A verb describes an action, state or event.

The verb ‘to be’

Use the verb is with single and uncountable nouns. For example: A heart is an organ.

M

Use the verb are with plural nouns. For example: There are many organs in the human body.

Other verbs

Verbs

I, you, we, they

look, explain, change, transfer, use

SA

Who or what

it, she, he

looks, explains, changes, transfers, uses

If you start a sentence with It, She or He, you must put an ‘s’ on the end of the verb.

It is easy to get confused with the letter ‘s’ at the end of English words.

Remember: an ‘s’ on the end of a noun usually makes it plural (for example: 1 vein, 2 veins).

Remember: an ‘s’ on the end of a verb makes it agree with it, she, he (for example: it reflects, she experiments).

Uncountable nouns describe things that are impossible to count, for example water, sand and oxygen. Uncountable nouns behave like it, she, he or singular things, and we add an ‘s’ to the end of verbs that follow these words.

Be careful, there are some irregular plural nouns, for example: 1 cactus, 2 cacti and 1 species, 2 species.

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English skills and support

Active and passive You will see sentences using active verbs and passive verbs in science. Sometimes you need to use passive verbs, but active sentences are easier to understand.

Active verbs Use active verbs in sentences to give direct and clear information.

• • • •

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Structure: Who does/did what.

Examples:

I observe the chemical reaction.

He dissolves sugar in water.

She can use indicator paper to test acidity.

The reaction produced hydrogen gas.

Passive verbs

Passive verbs in sentences are sometimes more confusing for learners of English.

Structure: Something is/are/was/were done by whom or what. It is possible not to include who did the action if it is not important who did it.

Example: The chemical reaction is observed (by me).

The sugar is dissolved in water (by him).

Indicator paper can be used (by her) to test acidity.

Hydrogen gas was produced by the reaction.

M

• • • •

Changing active to passive

SA

it, she, he Active

Who/what

verb

What

We

measure

the distance.

She

measures

the distances.

What

is/are + past participle

Who/what

The distance

is measured

by us.

The distances

are measured

by them.

Passive

Notice how the word order changes when you change active to passive.

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1

Respiration 1.1 The human respiratory system

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Exercise 1 Parts of the respiratory system This exercise gives you practice in naming and spelling the parts of the respiratory system.

SA

M

The diagram shows the head and chest cavity of a person.

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1.1 The human respiratory system

Choose the word or phrase that matches each description. Choose from the list.

Copy the words carefully – do not make any spelling mistakes! air sac bronchus bronchioles cartilage larynx respiratory system trachea vocal cords a

all the organs that work together to help oxygen to get into the body:

b

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………………………………… the tube that takes air from the back of the mouth down into the chest; it is sometimes called the windpipe ………………………………… c

one of two tubes that branches from the trachea …………………………………

d

an organ at the top of the trachea, which contains the vocal cords; it is sometimes called the voicebox …………………………………

a tiny, air-filled space inside the lungs …………………………………

f

the trachea is surrounded by rings of this, to support it

M

e

………………………………… g

bands of muscle that stretch across the larynx; they vibrate to make sounds

SA

…………………………………

h

tubes that carry air from a bronchus to the air sacs in the lungs …………………………………

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1 Respiration

Exercise 2 True or false?

This exercise gives you practice in writing positive and negative sentences, as well as checking your understanding of the respiratory system.

If the statement is true, tick (✓) it.

For example:

PL E

If the statement is false, draw a cross (✗). Then correct the statement by writing a positive or negative sentence.

The heart is part of the respiratory system. ✗

The heart is not part of the respiratory system. a

Respiration is a chemical reaction that happens in every living cell.

………………………………………………………………………………………. b

Aerobic respiration does not use oxygen.

……………………………………………………………………………………….

The vocal cords are inside the bronchus.

M

c

………………………………………………………………………………………. d

The plural of bronchus is bronchioles.

SA

………………………………………………………………………………………. e

The lungs do not contain air sacs. ……………………………………………………………………………………….

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1.2 Gas exchange

1.2 Gas exchange Exercise 1 Using connecting words

PL E

In this exercise, you choose the best connecting word to complete sentences about gas exchange.

Look at Connecting words in the English skills and support section for information about connecting words.

Choose a connecting word to complete each sentence. Choose from the following words. Use each word at least once. and because but so a

Oxygen can easily diffuse from the alveoli into the capillaries ........................... they are very close together.

b

Carbon dioxide is produced in all the cells in the body by respiration,

M

.......................... expired air contains more carbon dioxide than inspired air.

A large volume of air passes through the trachea, ....................... gas exchange does not happen there.

d

Gas exchange is the movement of oxygen into the blood ......................... the movement of carbon dioxide out of the blood.

SA

c

e

An analogy is a comparison between one thing and another, ............... the two things are not exactly the same.

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1 Respiration

Exercise 2 Answering questions It is important to do what the command word in a question asks you to do.

In this exercise, you practise responding to three different command words. a

Name the substance inside red blood cells that helps them to carry oxygen.

b

PL E

……………………………………………………………………………………….

Describe how oxygen moves from the alveoli into the blood.

………………………………………………………………………………………. ………………………………………………………………………………………. c

Explain why we can use limewater to compare how much carbon dioxide there is in inspired air and expired air.

………………………………………………………………………………………. ……………………………………………………………………………………….

SA

M

……………………………………………………………………………………….

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1.3 Breathing

1.3 Breathing Exercise 1 Comparatives.

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This exercise gives you practice in describing what happens when we breathe in and breathe out. You have to think of a comparative word to complete each description.

Look at Comparative and superlative adjectives in the English skills and support section for information about comparatives.

Arun can push more water out of the bottle than Marcus, showing that the

SA

a

M

Complete the sentences, using suitable comparative words.

capacity of his lungs is .............................. than Marcus’s.

b

In general, the .......................... a person’s lungs, the less air they can breathe out in one breath.

c

When we breathe out, the diaphragm relaxes and makes the space inside the chest cavity ........................... .

d

When we are breathing out, the pressure in the chest cavity is .......................... than the pressure of the air outside the body.

e

When we breathe in, the diaphragm contracts and makes the pressure inside the chest cavity ........................... .

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1 Respiration

Exercise 2 Opposites This exercise will help you to understand how we breathe in and out, and to use suitable words in your descriptions.

a

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Complete the sentences by writing a word or phrase that is the opposite of the one in bold.

Fill the bottle with water while it is the right way up, and then turn it ............................. ............................. . b

The intercostal muscles contract when we breathe in, and ............................. when we breathe out.

c

When the volume in the chest cavity increases, the pressure ............................. .

The ribs move upwards when we breathe in, and ............................. when we breathe out.

e

In the syringe, the balloon deflates when I push the plunger in and

M

d

............................. when I pull the plunger out.

SA

small hole

rubber bung syringe with end cut off balloon

10 20 30

plunger

40 50

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1.4 Respiration

1.4 Respiration Exercise 1 Observations, results, conclusions and explanations

PL E

This exercise will help you to sort out the differences between an observation, a result, a conclusion and an explanation.

Look at The language of science experiments in the English skills and support section for information about observations, results, conclusions and explanations.

SA

M

Sofia set up this apparatus.

potassium hydroxide solution to absorb carbon dioxide from air

limewater to detect carbon dioxide

healthy mouse

limewater to detect carbon dioxide

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1 Respiration

Sofia noticed that the limewater in the left-hand container did not go cloudy, even after a long time. After about 5 minutes, the limewater in the right-hand container went cloudy. The mouse appeared to be perfectly comfortable. Sofia thought that her experiment showed that the mouse produced carbon dioxide. a

What observations did Sofia make? ……………………………………………………………………………………….

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………………………………………………………………………………………. ………………………………………………………………………………………. ………………………………………………………………………………………. b

Describe the results of Sofia’s experiment.

………………………………………………………………………………………. ………………………………………………………………………………………. ………………………………………………………………………………………. c

What was Sofia’s conclusion?

M

………………………………………………………………………………………. ………………………………………………………………………………………. ……………………………………………………………………………………….

Write an explanation of how this apparatus works.

SA

d

………………………………………………………………………………………. ………………………………………………………………………………………. ………………………………………………………………………………………. ……………………………………………………………………………………….

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1.4 Respiration

Exercise 2 Modal verbs Modal verbs tell us about certainties and possibilities. In this exercise, you think about respiration and practise using modal verbs.

PL E

Look at Modal verbs in the English skills and support section for information about modal verbs.

Choose the best word or words to complete each sentence.

Choose from these words: might might not must must not

Cells ....................... have mitochondria so that they can carry out aerobic respiration.

b

Cells ......................... be provided with glucose so that they can carry out aerobic respiration.

c

If you do the experiment using the apparatus with the mouse in it, you

M

a

......................... take the mouse out if it looks uncomfortable.

If seeds are not given enough oxygen, they .................................. germinate.

e

If I do the experiment again, my results .............................. be exactly the same.

SA

d

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1 Respiration

1.5 Blood Exercise 1 Writing sentences about an analogy

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We use analogies to help us to understand a structure or a process.

An analogy compares the structure or process to something familiar.

In this exercise, you practise writing complete sentences.

The way that water flows through a pipe can be used as an analogy to help us to think about how blood flows through blood vessels. a

Describe how blood vessels are similar to a plastic water pipe.

………………………………………………………………………………………. ……………………………………………………………………………………….

Describe how blood vessels are different from a plastic pipe.

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b

………………………………………………………………………………………. ……………………………………………………………………………………….

Describe how blood is similar to water.

SA

c

………………………………………………………………………………………. ……………………………………………………………………………………….

d

Describe how blood is different from water. ………………………………………………………………………………………. ……………………………………………………………………………………….

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1.5 Blood

Exercise 2 Vocabulary There are many new words in this topic. This exercise helps you to check that you remember what each of them means.

Draw a line from each word to its meaning.

blood plasma red blood cells white blood cells haemoglobin

a red substance inside red blood cells microorganisms that cause disease the liquid part of blood

cells that help to destroy pathogens

a bright red compound formed when oxygen combines with haemoglobin

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oxyhaemoglobin

Meanings

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Words

chemicals, produced by white blood cells, that kill pathogens

phagocytosis

taking something into a cell and digesting it

SA

pathogens

antibodies

cells whose function is to transport oxygen

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