Key Stage 3 Science 9 Andy Cooke Jean Martin
Series editors Consultant Authors Andy Cooke Jean Martin Sam Ellis David Acaster Trevor Bavage Darren Beardsley Chris Christofi Zoe Crompton Sam Ellis Kevin Frobisher David Glover Helen Norris Jean Martin Sue McCarthy Mick Mulligan Nicky Thomas Doug Wilford 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 Alarcón 13, 28014 Madrid, Spain Dock House, The Waterfront, Cape Town 8001, South Africa http://www.cambridge.org Cambridge University Press 2003 First published 2003 Printed in the United Kingdom by BemroseBooth Typeface Delima MT System QuarkXPress A catalogue record for this book is available from the British Library ISBN 0 521 75011 3 paperback Cover design by Blue Pig Design Co Page make-up and illustration by hardlines Ltd, Charlbury, Oxford NOTICE TO TEACHERS The photocopy masters in this publication may be photocopied free of charge for classroom use within the school or institution which purchases the publication. Worksheets and photocopies of them remain in the copyright of Cambridge University Press and such photocopies may not be distributed or used in any way outside the purchasing institution. Written permission is necessary if you wish to store the material electronically.
Contents Introduction Page v Unit 9A Inheritance and selection 1 9A.1 What information is passed from parents? 1 9A.2 Why are we similar but not identical? 5 9A.3 Differences between offspring 10 9A.4 The right breed for the job 14 9A.5 How new varieties of plant are produced 20 9A.6 What is a clone? 26 Unit 9B Fitness and health 31 9B.1 Ideas about fitness 31 9B.2 Breathing in action 38 9B.3 The dangers of smoking 43 9B.4 Why your diet is important 53 9B.5 The use and abuse of drugs 58 9B.6 Fit for life 70 Unit 9C Plants and photosynthesis 81 9C.1 How do plants grow? 81 9C.2 Leaves and photosynthesis 87 9C.3 What happens to the glucose made in leaves? 98 9C.4 Roots, water and minerals 103 9C.5 Green plants and the environment 108 Unit 9D Plants for food 115 9D.1 Where does our food come from? 115 9D.2 How do fertilisers affect plant growth? 124 9D.3 Plants out of place 137 9D.4 Pests 144 9D.5 Producing more food 153 Unit 9E Reactions of metals and metal compounds 158 9E.1 Why are metals useful? 158 9E.2 Reacting metals with acids 165 9E.3 Reacting metal carbonates with acids 173 9E.4 Reacting metal oxides with acids 180 9E.5 More about salts 187 Unit 9F Patterns of reactivity 195 9F.1 What happens to metals? 195 9F.2 Metals and water 199 9F.3 Reactivity of metals with acids 204 9F.4 Metals and oxygen 210 9F.5 Displacement reactions 214 9F.6 Sources and uses of metals 222 9F.7 Investigating metals and acids further 229 iii Spectrum Key Stage 3 Science Cambridge University Press 2003
Unit 9G Environmental chemistry 233 9G.1 Are soils different from each other? 233 9G.2 Acid rain 244 9G.3 What causes acid rain? 251 9G.4 Can we reduce the amount of acid in rain? 257 9G.5 Is global warming really happening? 265 Unit 9H Using chemistry 272 9H.1 What chemical reactions take place when fuels burn? 272 9H.2 Chemical reactions as energy resources 290 9H.3 What new materials can chemical reactions make? 298 9H.4 Atoms and molecules in new materials 306 Unit 9I Energy and electricity 322 9I.1 How is energy involved in doing useful things? 322 9I.2 How does electricity transfer energy? 332 9I.3 Paying for and reducing the waste of electricity 343 9I.4 Where do we get electrical energy from? 351 Unit 9J Gravity and space 359 9J.1 What is gravity? 359 9J.2 How have our ideas about the Solar System changed? 367 9J.3 What keeps planets and satellites in orbit? 374 Unit 9K Speeding up 385 9K.1 Describing how fast something moves 385 9K.2 Working out the speed 390 9K.3 Force and speed 395 9K.4 Slowing things down 400 9K.5 Streamlining 408 9K.6 Skydiving and parachutes 413 Unit 9L Pressure and moments 423 9L.1 What is pressure? 423 9L.2 Gases under pressure 433 9L.3 Liquids under pressure 440 9L.4 Turning forces 448 9L.5 Balance and levers 455 Answers to Class Book questions 462 Summary activities 481 Scientific investigations 518 iv Spectrum Key Stage 3 Science Cambridge University Press 2003
Introduction 9A.1 What information is passed from parents? Link to QCA scheme of work This topic links to Unit 9A Learning Objectives, under the heading What characteristics can be inherited? Learning outcomes ALL pupils should be able to: understand that offspring are similar but not identical to parents; understand that some characteristics are inherited. MOST pupils should also be able to: describe similarities between parents and offspring; identify some inherited characteristics; identify features caused by the environment. SOME pupils should also be able to: find examples of, and distinguish between, inherited and environmental characteristics. Resources map Support Main route Extension Activity 9A.1a Class book pp. 1 2 Activity 9A.1b 1 Spectrum Key Stage 3 Science Cambridge University Press 2003 9A.1
Introduction 7A.2 9A.1 How What microscopes information helped is passed to change from our parents? ideas Activity notes Activity Guidance notes Resources Class book pp. 1 2 This section revises and reinforces ideas from Unit 7D. It provides teachers with an opportunity to find out what pupils already know. Pupils consider the characteristics of a range of organisms, including some that are inherited and some that are caused by the environment. Activity 9A.1a This activity, requiring less writing, supports the work in the class book. This could lead to a discussion of inherited and environmental characteristics. Activity 9A.1b This activity builds on work covered in the class book, allowing pupils to consider the uses of certain characteristics for the animal or plant or for humans, including breeding for a purpose. Pupils are given the opportunity to research a chosen animal or plant. If time permits, they could present their findings to the class. Access to information sources, e.g. library or the Internet Time (mins) 30 15 30 2 Spectrum Key Stage 3 Science Cambridge University Press 2003 9A.1
Support 7A.29A.1 How What microscopes information helped is passed to change from our parents? ideas Activity 9A.1a Inheritance or the environment? Use pages 1 and 2 to help you with this. Look at the drawing of a young footballer. Write down next to each characteristic whether you think it is an inherited characteristic or one affected by the environment. Write I if you think that it is an inherited characteristic. Write E if you think the environment affects it. The first one has been done for you. short hair E freckles black hair sweat pointed nose blue eyes left handed cut on leg 3 Spectrum Key Stage 3 Science Cambridge University Press 2003 9A.1a
Main 7A.29A.1 How What microscopes information helped is passed to change from our parents? ideas Activity 9A.1b What characteristics do animals inherit? The diagram shows some of the inherited characteristics of a racehorse. long neck to provide balance strong back for strength and flexibility large heart to pump blood quickly around the body strong legs for support large muscles for a long, fast stride 1 Why is it important that the horse has a large heart? 2 Why are strong legs useful for a racehorse? 3 Write down two other characteristics breeders select when they are breeding racehorses. 4 a Use books or the Internet to find out some inherited characteristics of one other animal or plant. b For three of the characteristics, explain why they are useful for the animal or plant. 4 Spectrum Key Stage 3 Science Cambridge University Press 2003 9A.1b