Key Stage 3 Science - Cambridge University Press & Assessment

[Pages:9]Key Stage 3 Science

Andy Cooke Jean Martin

Series editors Authors

Andy Cooke Jean Martin

Darren Beardsley Jenifer Burden Paul Butler Chris Christofi Andy Cooke Zoe Crompton Jean Martin Sue McCarthy

PUBLISHED BY THE PRESS SYNDICATE OF THE UNIVERSITY OF CAMBRIDGE The Pitt Building, Trumpington Street, Cambridge, United Kingdom

CAMBRIDGE UNIVERSITY PRESS The Edinburgh Building, Cambridge CB2 2RU, UK 40 West 20th Street, New York, NY 10011-4211, USA 477 Williamstown Road, Port Melbourne, VIC 3207, Australia Ruiz de Alarc?n 13, 28014 Madrid, Spain Dock House, The Waterfront, Cape Town 8001, South Africa

? Cambridge University Press 2004

First published 2004

Printed in Dubai by Oriental Press

Typeface Delima MT System QuarkXPress?

A catalogue record for this book is available from the British Library

ISBN 0 521 54921 3 paperback

Material in this book was previously published in Spectrum Year 7 Class Book (pp. 1?52), Spectrum Year 8 Class Book (pp. 1?50) and Spectrum Year 9 Class Book (pp. 1?49).

Cover design by Blue Pig Design Co Page make-up and illustration by Hardlines Ltd, Charlbury, Oxford

NOTICE TO TEACHERS 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.

Contents

Introduction

Unit 7A Cells: the body's building bricks

7A.1 What living things are made from 7A.2 How microscopes helped to change our ideas 7A.3 What cells are like 7A.4 Different cells for different jobs 7A.5 How new cells are made 7A.6 The secret life of plants

Unit 7B Reproduction

7B.1 How a new life starts 7B.2 The menstrual cycle 7B.3 The uterus as home to the developing baby 7B.4 Birth and care of the baby 7B.5 How humans change as they grow

Unit 7C Environment and feeding relationships

7C.1 Habitats 7C.2 Changing environmental conditions 7C.3 Investigating woodlice 7C.4 Seasonal change 7C.5 Feeding relationships 7C.6 Food webs

Unit 7D Variation and classification

7D.1 The same but different 7D.2 The causes of variation 7D.3 Describing living things 7D.4 Sorting things into groups 7D.5 Sorting plants and animals

Unit 8A Food and digestion

8A.1 Why we need food 8A.2 A healthy diet 8A.3 Getting nutrients out of your food 8A.4 How your digestive system works 8A.5 After digestion

Unit 8B Respiration

8B.1 How cells use food 8B.2 How oxygen reaches your tissues 8B.3 What happens to oxygen when it reaches the cells 8B.4 What happens in your lungs 8B.5 Comparing inhaled and exhaled air 8B.6 Other living things respire too

Page v

1

1 2 4 7 9 10

13

13 18 19 20 22

25

25 27 29 30 33 35

37

37 40 42 45 46

53

53 58 59 61 63

65

65 66 71 72 74 76

iii

Unit 8C Microbes and disease

8C.1 Micro-organisms and how to grow them 8C.2 Micro-organisms and disease 8C.3 Protecting ourselves against disease

Unit 8D Ecological relationships

8D.1 Animals, plants and adaptations 8D.2 Interactions in a habitat 8D.3 How living things depend on each other

Unit 9A Inheritance and selection

9A.1 What information is passed from parents? 9A.2 Why are we similar but not identical? 9A.3 Differences between offspring 9A.4 The right breed for the right job 9A.5 How new varieties of plant are produced 9A.6 What is a clone?

Unit 9B Fitness and health

9B.1 Ideas about fitness 9B.2 Breathing in action 9B.3 The dangers of smoking 9B.4 Why your diet is important 9B.5 The use and abuse of drugs 9B.6 Fit for life

Unit 9C Plants and photosynthesis

9C.1 How do plants grow? 9C.2 Leaves and photosynthesis 9C.3 What happens to the glucose made in leaves? 9C.4 Roots, water and minerals 9C.5 Green plants and the environment

Unit 9D Plants for food

9D.1 Where does our food come from? 9D.2 How do fertilisers affect plant growth? 9D.3 Plants out of place 9D.4 Pests 9D.5 Producing more food

Scientific investigations

Glossary/Index Acknowledgements

79

79 83 86

91

91 94 98

103

103 105 107 108 110 112

115

115 117 118 120 122 125

129

129 131 133 134 136

139

139 143 145 147 149

152

160 170

iv

7A

Cells: the body's building bricks

In this unit we shall be learning about some cells, tissues and organs in plants and animals.

7A.1 What living things are made from

Aristotle lived in Greece over 2000 years ago. He was very interested in plants and animals and in how the human body works. Look at the drawing by Aristotle of some parts of the human body. We call these parts organs. The Greeks weren't the only people interested in how the body works. Old drawings and texts from China and the Middle East also show human organs. Some even show plant organs. At first, information about organs came from operations and from cutting up dead bodies. Now we can look at X-rays and body scans, too.

KEY WORDS

organs tissues microscope cells nucleus scale cytoplasm cell membrane chloroplast vacuole cell wall

Cystis (bladder)

1 Write down the names of two organs that you can see on: a Aristotle's drawing; b the scan.

A closer look at human organs

In the late 18th century, a French doctor called Xavier Bichat did hundreds of post-mortems. Post-mortems are operations carried out on dead bodies to find out what killed them. Bichat found that each human organ contains more than one kind of material. He listed 21 different kinds. Today, we call these materials tissues. Bichat wasn't able to see the detailed cartilage structure of these tissues because he didn't have a microscope.

Aidoion (penis)

Orchis (testis)

Aristotle's drawing. The names in brackets are the ones that we use.

eye

skull

2 Look at this picture of part of a thigh bone. Write down the names of three tissues in this bone.

3 What do we use to see what the cells in these tissues are like?

Part of a thigh bone.

bone bone marrow

brain A scan through part of the head.

Unit 7A 1

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download