ON Science 9 Textbook PDF

ON Science 9 Authors Program Consultant ELL Consultants Leesa Blake Steve Bibla Maureen Innes B.Sc., B.Ed., M.A. B.Sc., B.Ed. B.A....

ON Science 9 Authors Program Consultant ELL Consultants Leesa Blake Steve Bibla Maureen Innes B.Sc., B.Ed., M.A. B.Sc., B.Ed. B.A. Toronto District School Board Toronto District School Board Nipissing University Michael Mazza Wendy Campbell Curriculum and Pedagogical B.Sc. B.A., B.Ed. Consultant Science Writer and Consultant Waterloo Region District School Board Tigist Amdemichael Alex Mills B.Sc., B.A., B.Ed., M.Ed. Al Tordjman B.Sc., M.Sc., LL.B., Ph.D. Toronto District School Board B.A., B.Ed. Science Consultant and Writer Waterloo Region District School Board Assessment Consultant Frank Mustoe Anu Arora Advisors B.Sc., B.Ed., M.Ed., Ph.D. Former Science Coordinator B.Sc. (Hons.), M.Sc., B.Ed. Anjuli Ahooja University of Toronto Schools Peel District School Board B.Sc. (Hons.), M.Sc., Ph.D. Curriculum Chair, Science and Technology Jim Ross Literacy and Environmental Appleby College B.Sc., B.Ed., M.Ed. Education Consultant Science Writer and Consultant Christina Clancy Steve Bibla B.Sc. (Hons.), M.Sc., B.Ed. B.Sc., B.Ed. Dufferin-Peel Catholic District School Board Thomas Stiff Toronto District School Board B.Sc., M.Sc., Ph.D. Lakehead University, Orillia Campus Lea Francis Consultant B.Sc.F., Dip.RM., B.Ed. Trudy L. Rising York Region District School Board Contributing Authors Katherine Hamilton Craig Jackson B.Sc., Ph.D. Aboriginal Consultants B.Sc., B.Ed., D.Met. Science Writer Chris Craig Independent Learning Centre, TVO South Ontario Conservation Authority Formerly of Kapuskasing District High School Natasha Marko Member of the Algonquins of B.Sc., M.Sc., M.A. Pikwakanagan Frank Mustoe Science Writer B.Sc., B.Ed., M.Ed., Ph.D. Francis McDermott Former Science Coordinator Jennifer Parrington Shabot Obaadjiwan Algonquin First Nation University of Toronto Schools B.Sc., B.Ed. Nibina Forestry York Region District School Board Paul Passafiume B.A.Sc., B.Ed. Betty R. Robinson Differentiated Instruction York Region District School Board Science Writer Consultant Jennifer Parrington Rob Smythe B.Sc., B.Ed. B.Sc., B.Ed., M.Sc.(T) York Region District School Board Halton District School Board Toronto Montreal Boston Burr Ridge, IL Dubuque, LA Madison, WI New York San Francisco St. Louis Bangkok Bogota Caracas Kuala Lumpur Lisbon London Madrid Mexico City Milan New Delhi Santiago Seoul Singapore Sydney Taipei Copies of this book may be ON Science 9 obtained by contacting: McGraw-Hill Ryerson Limited Copyright © 2009, McGraw-Hill Ryerson Limited, a Subsidiary of The McGraw-Hill Companies. All rights reserved. No part of this publication may be reproduced or e-mail: transmitted in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of McGraw-Hill Ryerson Limited, or, in the case [email protected] of photocopying or other reprographic copying, a licence from The Canadian Copyright Licensing Agency (Access Copyright). For an Access Copyright licence, call toll free to Toll-free fax: 1-800-893-5777. 1-800-463-5885 The information and activities in this textbook have been carefully developed and Toll-free call: reviewed by professionals to ensure safety and accuracy. However, the publisher shall not be liable for any damages resulting, in whole or in part, from the reader’s use of 1-800-565-5758 the material. Although appropriate safety procedures are discussed and highlighted throughout the textbook, the safety of students remains the responsibility of the or by mailing your order to: classroom teacher, the principal, and the school board district. McGraw-Hill Ryerson Limited Order Department ISBN-13: 978-0-07-072689-5 300 Water Street ISBN-10: 0-07-072689-2 Whitby, ON L1N 9B6 1234567890 TCP 8765432109 Please quote the ISBN and title when placing your order. Printed and bound in Canada Care has been taken to trace ownership of copyright material contained in this text. The publishers will gladly accept any information that will enable them to rectify any reference or credit in subsequent printings. Publisher: Diane Wyman Project Manager: Jane McNulty Development House: Pronk&Associates (Sara Goodchild, Assistant Editorial Director) Developmental Editors: Michelle Anderson, Kathy Hamilton, Betty Robinson, Gary Von Euer Managing Editor: Crystal Shortt COPY Editors: Linda Jenkins, Paula Pettitt-Townsend Photo Research/Permissions: Pronk&Associates (Matt Conacher, Senior Photo Researcher) Art Buying: Pronk&Associates (Jori Baldwin, Art Buyer) Review Coordinator: Jennifer Keay Features Coordination: Pronk&Associates (Tannys Williams, Editorial Project Manager) Editorial Assistant: Michelle Maida Manager, Production Services: Yolanda Pigden Production Coordinator: Sheryl MacAdam Set-Up Photography: Dave Starrett Set-Up Photography Coordination: Pronk&Associates (Christine Elliott, Senior Photo Researcher) Design and Production Coordination: Pronk&Associates (Luca Di Carlo, Project Coordinator) Cover/Interior Design: Pronk&Associates (Mark Cruxton, Senior Designer; Vince Satira, Designer) Electronic Page Make-Up: Pronk&Associates (Jack So, Production Lead; Chandra Ganegoda, Production Artist; Andrew Garcia, Production Artist) Acknowledgements Pedagogical Reviewers Stephen Jacobs Frank Villella Dufferin-Peel Catholic District Hamilton-Wentworth Catholic District Dave Black School Board School Board Upper Canada District School Board Mississauga, Ontario Hamillton, Ontario Brockville, Ontario Michele Laframboise Nathan Volkmann Susan Bouwer London District Catholic School Board London District Catholic School Board Grand Erie District School Board St. Thomas, Ontario St. Thomas, Ontario Brantford, Ontario Benjamin Law Nadia Camara Accuracy Reviewers York Region District School Board York Region District School Board Jenna Dunlop (Unit 1) Unionville, Ontario Richmond Hill, Ontario Science Writer Toronto, Ontario Beth Lisser Erin Connelly Peel District School Board Ottawa Catholic School Board R. Tom Baker (Unit 2) (North Field Office) Kanata, Ontario Canada Research Chair in Catalysis Brampton, Ontario Science for Energy Applications Cynthia M. de Souza Director, Centre for Catalysis Research Sharon MacLachlan York Catholic District School Board and Innovation Ottawa Catholic School Board Aurora, Ontario University of Ottawa Kanata, Ontario Ottawa, Ontario Katy Farrow Annette Nelson-Szpak Thames Valley District School Board Paul Delaney (Unit 3) Greater Essex County District London, Ontario Senior Lecturer, Dept, of Physics School Board and Astronomy Windsor, Ontario Monica Franciosa Director, Division of Natural Science York Catholic District School Board York University Robert J. Noble Richmond Hill, Ontario Toronto, Ontario Toronto Catholic District School Board Toronto, Ontario Patricia Gaspar Doug Roberts (Unit 4) York Region District School Board Professor Emeritus, University of Calgary Kamla Kerry-Ann Reid King City, Ontario Calgary, Alberta York Region District School Board Unionville, Ontario Vijay Gulati T.J. Elgin Wolfe (Unit 4) Toronto District School Board Professor, Ontario Institute for Studies Bob Roddie Toronto, Ontario in Education Hamilton-Wentworth Catholic District University of Toronto School Board Toronto, Ontario John Hallett Hamilton, Ontario Peel District School Board Caledon, Ontario Julie Silvestri Hamilton-Wentworth Catholic District School Board Hamilton, Ontario iii Safety Reviewer Literacy Reviewer Student Advisory Panel Jim Agban Joanie McCormick The authors, editors, and publisher of Past Chair, STAO Safety Committee Upper Grand District School Board ON Science 9 extend special thanks Mississauga, Ontario Fergus, Ontario to the students of Sinclair Secondary School in the Durham District School Board and St. Aloysius Gonzaga Lab Testers Special Features and Secondary School in the Dufferin Peel Toolkit Writers Catholic School Board for their guidance Lea Francis York Region District School Board J. Randy Attwood in the development of this learning King City, Ontario resource. Nancy Christoffer Jenna Dunlop Benjamin Law Set-up Photography Laura Edlund York Region District School Board We are very grateful to Lea Francis of Patricia Gaspar Unionville, Ontario King City Secondary School for her Eric Jandciu assistance in facilitating the set-up Renee Platt Natasha Marko photography session. Toronto Catholic District School Board Paul McNulty Toronto, Ontario Craig Saunders Julie Silvestri Hamilton Wentworth Catholic District Study Toolkit Writer School Board Kelly Stern Hamilton, Ontario Unit Project Writers Bias Reviewer Christina Clancy Nancy Christoffer Alex Mills Scarborough, Ontario Mary Kay Winter iv Contents Exploring ON Science 9...................................................................................................... xii Safety in your Science Classroom................................................................................... xiv Unit 1 Sustainable Ecosystems.........................xviii Get Ready for Unit 1............................................................................................................. 2 Chapter 1 Nutrient Cycles and Energy Flow.................................... 4 1.1 Sustainability................................................................................................................. 7 1.2 The Biosphere and Energy........................................................................................ 21 1.3 Extracting Energy from Biomass............................................................................28 Chapter 1 Summary.............................................................................................................43 Chapter 1 Review.................................................................................................................44 Chapter 2 Populations and Sustainable Ecosystems.................... 46 Populations and Resources...................................................................................... 49 2.2 Interactions Among Species.................................................................................... 56 2.3 Human Niches and Population................................................................................ 65 2.4 Ecosystem Services.................................................................................................... 69 Chapter 2 Summary............................................................................................................ 83 Chapter 2 Review................................................................................................................ 84 Chapter 3 Biodiversity....................................................................... 86 3.1 Measuring Biodiversity.............................................................................................. 89 3.2 Communities.................................................................................................................95 3.3 Threats to Biodiversity............................................................................................ 100 3.4 Restoration Ecology.................................................................................................110 Chapter 3 Summary........................................................................................................... 121 Chapter 3 Review...............................................................................................................122 Unit 1 Science at Work.................................................................................................... 124 Unit 1 Projects..................................................................................................................... 126 Unit 1 Review..................................................................................................................... 128 v  Unit 2 Atoms, Elements, and Compounds......... 132 Get Ready for Unit 2...................................................................................................... 134 Chapter 4 Properties of Elements and Compounds.................... 136 4.1 Studying Matter........................................................................................................ 139 4.2 Physical Properties.................................................................................................. 149 4.3 Chemical Properties................................................................................................ 160 Chapter 4 Summary........................................................................................................... 173 Chapter 4 Review............................................................................................................... 174 Chapter 5 Understanding the Properties of Elements............... 176 5.1 Evolution of the Atomic Model.............................................................................. 179 5.2 The Structure of the Atom...................................................................................... 187 5.3 The Periodic Table.................................................................................................. 194 5.4 Trends in the Periodic Table..................................................................................207 Chapter 5 Summary...........................................................................................................215 Chapter 5 Review...............................................................................................................216 Chapter 6 Understanding the Properties of Compounds............ 218 6.1 Ionic Compounds...................................................................................................... 221 6.2 Covalent Compounds.............................................................................................. 232 6.3 Modelling Compounds............................................................................................ 242 Chapter 6 Summary.......................................................................................................... 253 Chapter 6 Review.............................................................................................................. 254 Unit 2 Science at Work.................................................................................................... 256 Unit 2 Projects.....................................................................................................................258 Unit 2 Review.................................................................................................................... 260 vi Unit 3 The Study of the Universe...................... 264 Get Ready for Unit 3....................................................................................................... 266 Chapter 7 The Night Sky.................................................................. 268 7.1 Ancient Astronomy.................................................................................................. 271 7.2 The Constellations.................................................................................................... 277 7.3 Movements of Earth and the Moon..................................................................... 283 7.4 Meet Your Solar System.......................................................................................... 291 7.5 Other Objects in the Solar System....................................................................... 297 Chapter 7 Summary...........................................................................................................311 Chapter 7 Review...............................................................................................................312 Chapter 8 Exploring Our Stellar Neighbourhood......................... 314 8.1 Exploring Space........................................................................................................ 317 8.2 Exploring the Sun.................................................................................................... 333 8.3 Exploring Other Stars.............................................................................................. 341 Chapter 8 Summary.......................................................................................................... 355 Chapter 8 Review.............................................................................................................. 356 Chapter 9 The Mysterious Universe............................................... 358 9.1 Galaxies.......................................................................................................................361 9.2 The Universe............................................................................................................ 368 9.3 Unsolved Mysteries.................................................................................................. 377 Chapter 9 Summary.......................................................................................................... 385 Chapter 9 Review.............................................................................................................. 386 Contents MH  Unit 4 The Characteristics of Electricity............396 Get Ready for Unit 4........................................................................................................ 398 Chapter 10 Static Charges and Energy.......................................... 400 10.1 Exploring Static Charges..................................................................................... 403 10.2 Charging by Contact and by Induction............................................................... 411 10.3 Charges at Work...................................................................................................... 418 Chapter 10 Summary........................................................................................................ 431 Chapter 10 Review............................................................................................................ 432 Chapter 11 Electric Circuits............................................................. 434 11.1 Cells and Batteries................................................................................................ 437 11.2 Electric Circuits: Analogies and Characteristics.............................................. 446 11.3 Measuring the Properties of Simple Circuits.................................................. 455 11.4 Measuring Electrical Resistance......................................................................... 462 11.5 Series and Parallel Circuits................................................................................. 468 Chapter 11 Summary........................................................................................................ 479 Chapter 11 Review............................................................................................................ 480 Chapter 12 Generating and Using Electricity............................... 482 12.1 Electricity at Home................................................................................................ 485 1 2.2 Using Electrical Energy Wisely........................................................................... 492 Meeting the Demand for Electricity................................................................... 501 12.4 Sustainable Sources of Electricity..................................................................... 506 Chapter 12 Summary.........................................................................................................517 Chapter 1 2 Review.............................................................................................................518 Unit 4 Science at Work.................................................................................................... 520.................................................................................................................... 522 Unit 4 Review.....................................................................................................................524 viii Guide to the Toolkits and Appendices............................................ 528 Science Skills Toolkits........................................................................ 529 Math Skills Toolkits............................................................................. 554 Study Toolkits..................................................................................... 561 Appendix A: Properties of Common Substances.......................... 568 Appendix B: Using Star Maps............................................................570 Appendix C: Chemistry References.................................................. 572 Appendix D: Numerical Answers and Answers to Practice Problems.................................. 573 Glossary................................................................................................ 574 Index..................................................................................................... 582 Credits................................................................................................... 588 Periodic Table...................................................................................... 590 ix Activities, Investigations, and Features Activities 7- 4 Making Craters....................................................... 303 1-1 How Disturbed Is Too Disturbed?................................ 5 8- 1 Preparing for a Trip to the Moon........................... 315 8- 2 An Astronomer's View............................................ 318 1- 2 What Symbol Would You Choose?.......................... 11 1 -3 Recycling in Ontario................................................... 32 9- 1 Matter in Motion...................................................... 359 2- 1 Reducing Wildlife Mortality with Fences................ 47 9-2 How Big Is the Milky Way Galaxy?......................... 365 9-3 Counting Galaxies by Sampling............................ 366 2-2 Graphing Population Change..................................... 52 10-1 Lightning in a Glow Tube....................................... 401 2-3 What Was for Dinner?................................................60 2- 4 Ecotourism and Monarch Butterflies........................ 76 2 10- Detecting Static Charge Using an Electroscope.. 412 10-3 Drawing Charges You Cannot See......................... 416 3- 1 Biodiversity in Canada.............................................. 87 3-2 Biodiversity Index..................................................... 93 10- 4 A Static Spice Separator......................................... 426 3-3 Alien Invasion.......................................................... 104 11- 1 Shed Light On It..................................................... 435 3-4 Plants at Risk............................................................ 108 11 -2 Make a CELLection.................................................. 441 11 -3 Charged Cereal and Moving Marbles..................... 449 3- 5 The Common Good................................................... 113 11 -4 Measuring Current and Potential 4- 1 Raisin' Underwater Artifacts...................................137 Difference in a Series Circuit.................................. 459 4-2 Safety First!.............................................................. 141 12- 1 Generating an Electric Current.............................. 483 4-3 Element, Compound, or Mixture?........................... 145 4-4 What's So Special about Paper Clips?.................... 150 4-5 Slow as Molasses..................................................... 151 Investigations 4-6 Hard as Nails.............................................................155 1 -A Fertilizers and Algae Growth..................................... 37 4- 7 What’s New?............................................................ 162 1 -B The Chemistry of Photosynthesis........................... 38 5- 1 The Atomic "Black Box"............................................ 177 1- C Soil-water Acidity and Plant Growth........................40 5-2 How Small Is Too Small?.......................................... 180 1 -D Can a Plant Have Too Much Fertilizer?.................... 42 5-3 Atomic Model Time Line.......................................... 185 2- A Is the Winter Skate Endangered in Nova Scotia?.. 79 5-4 What's Your Number?............................................. 189 2-B What Happens When Food Is Limited?.................... 80 5-5 Make Your Own Atom..............................................191 2- C Putting Your Foot in Your Mouth............................. 82 5-6 What's in Blackbock's Lake?.................................... 195 3- A Zebra Mussels in Lake Ontario............................... 117 5- 7 The Bohr-Rutherford Periodic Table..................... 208 3- B Balancing Populations and the Environment.... 118 6- 1 Bouncing Glue.......................................................... 219 4- A Testing Physical Properties of Substances......... 166 6-2 Making Ice Cream..................................................... 229 4-B Chemical Properties of Common Gases................ 168 6-3 Cornstarch Armour.................................................. 240 4-C Properties of Common Substances....................... 170 4 6- Representing Compounds Using 4- D CFC Production and Canada's Ozone Layer......... 172 Bohr-Rutherford Models......................................... 244 5- A The Bohr-Rutherford Model of the Atom............. 212 6- 5 Ball-and-Stick Models............................................. 246 5- B Physical Properties of Metals and Non-metals... 213 7- 1 Create Your Own Constellation...............................269 5- C Reactivity Trends in the Periodic Table................ 214 7-2 Angle of Sunlight..................................................... 285 6- A What Causes Rusting of Iron Nails?....................... 249 7-3 Modelling the Solar System.................................... 293 6- B Properties of Ionic and Covalent Compounds.... 250 X  6- C Classification of Household Substances............. 252 Making a Difference 7- A Modelling the Moon's Movement......................... 307 Yvonne Su................................................................................. 11 7-B The Changing View of the Night Sky.................. 308 Allyson Parker......................................................................... 77 7- C Gravity on Other Planets........................................ 310 Severn Cullis-Suzuki............................................................ 101 8- A The Brightness of Stars......................................... 350 Meghana Saincher................................................................ 147 B 8- Using Spectral Analysis to Identify Patrick Bowman................................................................... 204 Star Composition.....................................................352 Dayna Corelli.........................................................................240 8- C Building an H-R Diagram...................................... 354 Shelby Mielhausen............................................................... 280 9- A Estimating the Age of the Universe.................... 382 Roberta Bondar..................................................................... 328 9-B Modelling the Expanding Universe...................... 384 Joel Zylberger....................................................................... 379 10-A Comparing Conductivity........................................ 429 Katie Pietrzakowski............................................................. 427 10- B Be a Charge Detective............................................ 430 Corey Centen and Nilesh Patel......................................... 444 11 -A Constructing and Comparing Voltaic Cells........... 472 Pinky Langat and Chris Palmer............................................ 511 11- B Loads in Series........................................................ 474 11-C Loads in Parallel...................................................... 476 11- D Testing Ohm's Law................................................... 478 National Geographic Features 12- A Designing a Staircase Circuit...................................513 Visualizing the Carbon Cycle.................................................. 15 12-B An Electrical Energy Audit...................................... 514 Visualizing Metals................................................................201 12-C A "Dry" Investigation............................................... 515 Visualizing the Kuiper Belt................................................. 298 12-D A Plan of Action....................................................... 516 Visualizing Lightning............................................................ 419 Case Studies The Disappearing Eel............................................................... 8 Why Are Honeybees Disappearing?..................................... 72 Saving Dolly Varden.............................................................. 106 What Is the Cost of Our Products?...................................... 146 Diamond Mining: Beyond the Sparkle................................ 202 Taking a Stand on Plastic Bags........................................... 238 Can We Prevent the Next Big Impact?.............................. 304 Space Junk............................................................................ 330 Space Exploration Spinoffs................................................. 370 E-waste.................................................................................. 422 Electric Avenue..................................................................... 442 Off the Grid and Living Green............................................. 508 xi Exploring ON Science 9 Solve a Puzzle, Find a Quote Use the puzzle clues on these two pages to begin your journey through ON Science 9. (Do not write in this textbook.) When you are finished, the circled and numbered letters will help you discover a powerful quote by Albert Einstein. Driven by curiosity and hard work, Albert Einstein developed theories that revolutionized our understanding of space, matter, and time. What other factor helped Einstein achieve such success in science? What does this quote reveal about Einstein's approach to science? How can you apply this approach to your studies in science? Engage—Learning Science What are the four units you will study in ON Science 9? Features in the margins throughout each chapter help you understand science through fascinating facts and figures. Three of these "Sense Of" features are shown below. Which one is missing? xii Explore—Doing Science Explain—Understanding Science What piece of safety equipment National Geographic features help you understand does this icon represent? science through images. What is the title of the National Geographic feature in Unit 4? The Activities and Investigations in your textbook will help you explore and investigate questions Learning how to understand and use science about your world using the skills of scientific inquiry. vocabulary is an important communication skill. Which is the missing skill in the Skill Check below? What colour is used to highlight key terms and their definitions in the margin? Skill Check Performing and Recording Analyzing and Interpreting Communicating Suppose you are reviewing terms and definitions to study for a test. What part of this textbook can help you? Where would you look in this textbook to find out how to make a scientific drawing? Extend—Applying Science Evaluate—Studying Science Every chapter has a feature that explores a specific What feature, at the beginning of each chapter, real-world scientific topic or issue that relates to provides three strategies to help you learn the that chapter. Questions at the end of the feature material in your science textbook? challenge you to find out more about the topic. The feature runs along the bottom of two pages. What is the feature called? Section Review questions, Chapter Review questions, and Unit Review questions all help you check your understanding. What question category helps you In each chapter you will have the opportunity to test your understanding as you read through a read about young Canadians, most of them high section? school students, who have used the tools of scientific inquiry to positively influence their community, the environment, or some other facet of their lives. What is the name of this feature? Answers to some of the review questions are included in this textbook. Where are they? What feature focusses on careers in science? xiii Safety in your Science Classroom Become familiar with the following safety rules and 3. Wearing protective clothing... procedures. It is up to you to use them and your When you are directed to do so, wear teacher’s instructions to make your activities and protective clothing, such as a lab apron investigations in ON Science 9 safe and enjoyable. and safety goggles. Always wear protective Your teacher will give you specific information clothing when you are using materials about any other special safety rules that need to be that could pose a safety problem, such as used in your school. unidentified substances, or when you are 1. Working with your teacher... heating anything. Listen carefully to any instructions your Tie back long hair, and avoid wearing scarves, teacher gives you. ties, or long necklaces. Inform your teacher if you have any allergies, 4. Acting responsibly... medical conditions, Work carefully with a partner and make sure or other physical problems that could affect your work area is clear. your work in the science classroom. Tell your Handle equipment and materials carefully. teacher if you wear contact lenses or a hearing Make sure stools and chairs are resting aid. securely on the floor. Obtain your teachers approval before If other students are doing something that beginning any activity you have designed for you consider dangerous, report it to your yourself. teacher. Know the location and proper use of the nearest fire extinguisher, fire blanket, first-aid 5. Handling edible substances... kit, and fire alarm. Do not chew gum, eat, or drink in your 2. Starting an activity or investigation... science classroom. Before starting an activity or investigation, Do not taste any substances or draw any read all of it. If you do not understand how to material into a tube with your mouth. do a step, ask your teacher for help. Be sure you have checked the safety icons and have read and understood the safety precautions. Begin an activity or investigation only after your teacher tells you to start. xiv 6. Working in a science classroom... Make sure you understand all safety labels on school materials or those you bring from home. Familiarize yourself, as well, with the WHMIS symbols and the special safety symbols used in this book, found on page xvii. When carrying equipment for an activity or investigation, hold it carefully. Carry only one object or container at a time. Be aware of others during activities and investigations. Make room for students who may be carrying equipment to their work stations. 7. Working with sharp objects... Always cut away from yourself and others when using a knife or razor blade. Always keep the pointed end of scissors or any 9. Working with heat... pointed object facing away from yourself and When heating an item, wear safety goggles others if you have to walk with such objects. and any other safety equipment that the text If you notice sharp or jagged edges on any or your teacher advises. equipment, take special care with it and report Always use heatproof containers. it to your teacher. Point the open end of a container that is Dispose of broken glass as your teacher being heated away from yourself and others. directs. Do not allow a container to boil dry. 8. Working with electrical equipment... Handle hot objects carefully. Be especially Make sure your hands are dry when touching careful with a hot plate that looks as though it electrical cords, plugs, or sockets. has cooled down. Pull the plug, not the cord, when unplugging If you use a Bunsen burner, make sure you electrical equipment. understand fully how to light and use it safely. Report damaged equipment or frayed cords to If you do receive a burn, inform you teacher, your teacher. and apply cold water to the burned area Place electrical cords where people will not immediately. trip over them. XV 10. Working with various chemicals... In the classroom: If any part of your body comes in contact with Make sure that living creatures receive a substance, wash the area immediately and humane treatment while they are in your thoroughly with water. If you get anything care. in your eyes, do not touch them. Wash them If possible, return living creatures to their immediately and continuously for 15 min, and natural environment when your work is inform your teacher. complete. Always handle substances carefully. If you 12. Cleaning up in the science classroom... are asked to smell a substance, never smell it Clean up any spills, according to you teacher’s directly. Hold the container slightly in front instructions. of and beneath your nose, and waft the fumes toward your nostrils. Clean equipment before you put it away. Hold containers away from your face when Wash your hands thoroughly after doing an pouring liquids. activity or an investigation. Dispose of materials as directed by your 11. Working with living things... teacher. Never discard materials in the sink On a field trip: unless your teacher requests it. Try not to disturb the area any more than is absolutely necessary. 13. Designing and building... Use tools safely to cut, join, and shape If you move something, do it carefully, and objects. always replace it carefully. Handle modelling clay correctly. Wash your If you are asked to remove plant material, hands after using modelling clay. remove it gently, and take as little as possible. Follow proper procedures when using mechanical systems and studying their operations. Use special care when observing and working with objects in motion. Do not use power equipment such as drills, sanders, saws, and lathes unless you have specialized training in handling such tools. xvi Safety Symbols ON Science 9 Safety Symbols WHMIS Symbols The following safety symbols are used in ON Look carefully at the WHMIS (Workplace Science 9 to alert you to possible dangers. Be sure Hazardous Materials Information System) safety you understand each symbol used in an activity or symbols shown here. The WHMIS symbols are used investigation before you begin. throughout Canada to identify dangerous materials. Make certain you understand what these symbols Disposal Alert mean. When you see these symbols on containers, This symbol appears when care must be taken use safety precautions. to dispose of materials properly. Thermal Safety This symbol appears as a reminder to use caution when handling hot objects. Compressed Gas Flammable and Sharp Object Safety Combustible Material This symbol appears when a danger of cuts or punctures caused by the use of sharp objects exists. Electrical Safety Oxidizing Material Corrosive Material This symbol appears when care should be taken when using electrical equipment. Skin Protection Safety This symbol appears when use of caustic Poisonous and Infectious Poisonous and Infectious chemicals might irritate the skin or when Material Causing Immediate Material Causing Other contact with micro-organisms might and Serious Toxic Effects Toxic Effects transmit infection. Clothing Protection Safety A lab apron should be worn when this symbol appears. Biohazardous Infectious Dangerously Reactive Material Material Fire Safety This symbol appears when care should be taken around open flames. Instant Practice—Safety Symbols Hydrogen gas is stored in containers under pressure. Eye Safety This symbol appears when a danger to the This gas is highly flammable. eyes exists. Safety goggles should be worn 1. What two symbols would you expect to see on when this symbol appears. a label for hydrogen gas? 2. Describe the following. a. the risks illustrated by the two symbols Instant Practice—Safety Symbols b. precautions someone would need to take when Find four of the ON Science 9 safety symbols in working with the gas activities or investigations in this textbook. For each symbol, identify the possible dangers in the activity or c. where it could be safely stored investigation that the symbol refers to. d. first aid or emergency treatment 3. If you did not know the answer to part d„ where would you find this information? xvii Unit 1 Sustainable Ecosystems  People have the responsibility to regulate their impact on the sustainability of ecosystems in order to preserve them for future generations. Ecosystems are dynamic and have the ability to respond to change, within limits, while maintaining their ecological balance. Roads provide pathways for many human journeys. Roads also divide habitats, forcing animals to face dangers from fast-moving vehicles when the animals migrate or travel within their habitat. Posting warning signs to remind drivers to slow down and watch for animals is one way to reduce collisions and wildlife deaths on our roads. A road dividing a habitat is an example of human activity that has disturbed an ecosystem. An ecosystem can respond to disturbances—but only within limits. Beyond those limits, the ecosystem cannot recover its ecological balance. In this unit, you will learn about why sustainable ecosystems are crucial to life on Earth and what people can do to help protect them. Why does it matter if an animal's habitat is divided? Chapter 3 Chapter 2 Biodiversity Chapter 1 Populations and Sustainable Ecosystems Nutrient Cycles and Energy Flow 1 Get Ready for Unit 1 Concept Check 3. The food chain shown below is just one of many food chains in a forest ecosystem. Using 1. Examine the forest ecosystem shown in the the organisms shown in the forest ecosystem illustration below. Make a table with the headings illustration, draw a different food chain. “Biotic” and “Abiotic”. Give your table a title. Under each heading, list the components of the 4. Use the words below to write a brief explanation forest ecosystem that belong to that category. of why trees are important to forest ecosystems. producers food shade Biotic Abiotic oxygen leaves plants habitat decompose photosynthesis 5. Choose one of the following events. Make a flowchart to show how the event might affect 2. Complete each of the following sentences, using a forest ecosystem. one of the organisms from the forest ecosystem shown below to fill in the blanks. (Do not write a. A forest fire rages through the forest. in this textbook.) The first sentence is completed b. A logging company clear-cuts the trees in for you. the forest. a. A puffball mushroom is a decomposer c. A beaver builds a dam in a nearby pond because it breaks down the remains of dead that results in the stream drying up. animals and plants. d. Hunters kill all of the wolves in the area. b. A is a scavenger because... e. An invasive species of beetle kills all of the c. A is a producer because... pine trees in the area. d. A is a consumer because... e. A is a herbivore because... f. A is a carnivore because... g. A is an omnivore because... 2 Inquiry Check Numeracy and Literacy Check The Ontario Ministry of Transport has taken The five areas of Ontario with the highest number several steps to try to prevent vehicle collisions with of reported vehicle collisions with wildlife are deer, moose, and bears. Researchers found out that shown below. They are listed in alphabetical order. most of these collisions happened in May, June, Ontario's Highest Number of Reported Wildlife October, November, and December. Collisions 6. Analyze In which two seasons do most Number of incidents Area Human populatlion per year in 1997 collisions with deer, moose, and bears occur? Why do you think this is the case? Explain Kenora 15,177 521 your answer. Lanark County 62,495 481 7. Predict Which of the government strategies for Ottawa 774,072 886 reducing collisions listed below might be the Simcoe County 266,100 656 most effective? Explain your answer. Thunder Bay 109,140 463 a. Installing fencing along major highways b. Draining salty ponds near highways 9. Ranking List the areas in order from highest to c. Posting warning signs lowest number of incidents. d. Adding highway lighting to improve 10. Graphig n Choose an appropriate style of night visibility graph and construct a graph to display the e. Removing roadside brush so drivers can see information shown in the table. Include a title the road bette and labels. 8. Plan You are a scientist hired by the ministry to 11. Writing Suppose you are a speechwriter for the investigate its anti-collision strategies. Choose Mayor of Simcoe County. Write a brief radio one of the five strategies above. Outline a message aimed at informing people about the procedure to test how well the strategy works. dangers of collisions with wildlife on the roads and suggesting ways to avoid them. — Looking Ahead to the Unit 1 Projects At the end of this unit, you will have an opportunity to apply what you have learned in an inquiry or research project. Read the Unit 1 Projects on pages 126-127. Start a project folder now (either paper or electronic). Store ideas, notes, news clippings, websites, and lists of materials that might help you to complete your project. Inquiry Project Investigate how common substances affect the sustainability of aquatic An Issue to Analyze ecosystems. Identify and reduce threats to a local ecosystem. 3 Chapter 1 Nutrient cycles and energy flow What You Will Learn In this chapter, you will learn how to... explain that life depends on recycled matter describe the processes of photosynthesis and cellular respiration explain how humans can affect the cycles of matter and energy flow in ecosystems Why It Matters All living things, including humans, rely on the cycles of matter and energy on Earth. When a natural process or human activity affects one of these cycles, the balance of an ecosystem can be thrown off. This imbalance can affect all the organisms in the ecosystem. Skills You Will Use In this chapter, you will learn how to... assess the impact of fertilizers on aquatic ecosystems observe the chemistry of photosynthesis model acid precipitation determine the impact of excess fertilizers on plants In 2007, four First Nations-Poplar River, Little Grand Rapids, Paunigassi, and Pikangikum and the governments of Manitoba and Ontario began the process required to designate an area of Canada as a World Heritage Site. The area includes the territories of the four First Nations, Atikaki Provincial Park in Manitoba, and Woodland Caribou Provincial Park in Ontario, shown above. As a World Heritage Site, the sustainability of the area's forest, lake, and wetland ecosystems would be protected. 4 How Disturbed Is Too Disturbed? Many different types of disturbances can affect an ecosystem. Some disturbances, such as a volcanic eruption or a flood, are natural. Other disturbances, such as water pollution or air pollution, can result from human activities. In this activity, you will model how disturbances can affect the balance of an ecosystem. Materials 27 smooth building blocks, labelled with environmental disturbances How much instability can your tower take? Procedure 1. Work in groups of four. Build a tower with nine layers, using three blocks per layer. Place each layer at right angles to the layer below it. 2. Take turns removing blocks from the lower levels of the tower and using these blocks to make new three-block layers on top. Keep track of how many blocks you move. 3. Continue moving blocks until the tower collapses. Questions 1. What did the tower represent in this model? What did the moved blocks represent? 2. What happened to the tower as more blocks were removed from lower levels and placed on top? 3. How does this activity model how different disturbances can affect an ecosystem? 4. How does what happened to the model in this activity differ from what could happen in a real ecosystem? 5 Study Toolkit These strategies will help you use this textbook to develop your understanding of science concepts and skills. To find out more about these and other strategies, refer to the Study Toolkit Overview, which begins on page 561. Preparing For Reading Organizing Your Learning Previewing Text Features Comparing and Contrasting Before reading nonfiction text, a good strategy is to Comparing and contrasting helps you identify how preview the features of the text. Text features give concepts are similar and how they are different. readers clues about the main ideas in the text and A Venn diagram can help you organize this information show how the writer has organized these ideas. graphically. For example, the Venn diagram below Look at some text features on the next page. shows some similarities and differences between The section heading, 1.1 Sustainability, is a different "biotic" and "abiotic" characteristics of the environment. size and colour from the body text. This heading tells you the main idea of the section. The two subheadings, The Mystery of Easter Island and The Need for Sustainable Ecosystems, are specific and signal details related to the main idea. Use the Strategy 1. Browse through Chapter 1, paying attention to the section headings and subheadings. Predict what the main ideas in Chapter 1 will be. Record your predictions and confirm or revise them as you read the chapter. 2. Describe two ways in which colour is used in the chapter to help you navigate. Use the Strategy 1. Choose two animals, such as an owl and a turtle. 2. Make a Venn diagram to show the similarities and differences between the two animals in terms of their survival needs. Word Study Word Families Drawing a word family web can help you figure out unfamiliar words. The web on the right shows biology words that all have the prefix bio, from the Greek word meaning life. Biology, for example, means the study of life. Use the Strategy 1. Predict and record what you think the other words in the web mean. biosphere 2. Check your predictions as you read Chapter 1 or use the Glossary at the end of this textbook. 6  Key Terms ecosystem sustainable ecosystem 1.1 Sustainability biotic abiotic On Easter day in 1722, a Dutch ship landed on a small treeless island in lithosphere the South Pacific. A small population of people lived on the island. Along hydrosphere the coast, there were many giant rock statues of human forms, shown in atmosphere Figure 1.1. Some of these statues were as tall as 10 m. How could so few biosphere people put together so many large statues? nutrients aquatic ecosystem The Mystery of Easter Island terrestrial ecosystem eutrophication Many scientists theorize that there was once a thriving population of people on Easter Island, as well as thick forests. The people had come from other islands in the South Pacific, thousands of kilometres away. They built ecosystem all the houses, planted crops, and raised the animals they had brought with them. interacting parts of a They also built the giant rock statues. biological community and its To move the statues from the rock quarry to the coast, they cut down environment trees and made wooden frames. In addition, the islanders cut down sustainable ecosystem trees to clear the land for their crops and to burn the wood for warmth. an ecosystem that is capable Eventually, the last tree was cut down. The loss of trees led to erosion, a of withstanding pressure and loss of plants for food, and no materials for making boats for fishing—or giving support to a variety of organisms escape. Without the supporting forest, the island could no longer sustain the human population. Their standard of living declined, and their society began to die off. The disappearance of the forests also led to the disappearance of other island residents, such as birds. The Need for Sustainable Ecosystems The forests that once grew on Easter Island are an example of an ecosystem. An ecosystem includes all the interacting parts of a biological community and its environment. The prefix eco is from the ancient Greek word for home. This is a fitting prefix, since ecosystems are the natural homes of the many organisms that live in them. When the term sustainable ecosystem is used, the word sustain has two meanings: to endure and to support. Figure 1.1 The cost of erecting these massive statues was the destruction of the sustaining forests on Easter Island. 7  Ecosystems and Survival “To endure” means to continue in the same state. Sustainable ecosystems endure, but they also support a wide variety of organisms. The Easter Islanders’ use of their forest ecosystem was unsustainable. Under the pressure of the tree cutting, the ecosystem could not endure, nor could it support many of the organisms, including humans, on the island. All organisms require sustainable ecosystems for survival. Many organisms depend on more than one ecosystem to survive. Ruby-throated hummingbirds, shown in Figure 1.2, spend the summer in gardens and along the edges of forests of eastern Canada. In the fall, they fly thousands of kilometres to spend the winter in the tropical forests of Central America. In the spring, they begin the long flight back to Canada. Along the way, they stop to drink water, eat nectar and insects, and rest. Because these birds, and many others, migrate long distances every year, they are dependent on the many ecosystems along their migratory route for food and shelter. Figure 1.2 Ruby-throated hummingbirds fly north from Mexico each spring. Along the way, they need resources from sustainable ecosystems to survive, Case Study The Disappearing Eel The American eel, shown on the right, was once one of the most abundant fish in the St. Lawrence River. The species was so plentiful that there are accounts from the mid 1600s of a person catching 1000 eels in one night with just a spear! Today, the situation has changed. The estimated number of American eels in the St. Lawrence and Great Lakes has decreased by more than 90 percent. The appearance of an American eel changes American eels found in the Great Lakes are long, snake-like many times as it makes its long journey fish. They are a native species and have an important role from the Sargasso Sea to the Great Lakes. in the Great Lakes ecosystem, Eels eat insects, crustaceans, fish, frogs, and dead animals. They are prey for other fish, birds, and mammals. About 40 percent of these eels are shredded and killed in American eels migrate great distances and change dam turbines in the river. Dams also block young eels dramatically during their life cycles, as shown on the next migrating upstream toward the Great Lakes. page. Eels are catadromous: they spend most of their lives in Overfishing has contributed to the decline of American fresh water, but return to the sea to lay eggs. Both saltwater eels. Ontario cancelled its eel fishery in 2004, but eel fishing and freshwater species and their ecosystems are affected takes place elsewhere. Overharvesting of seaweed, which by a decrease in the eel population. makes up the spawning habitat for eels, could also be Because the eel's life cycle is so long and covers so contributing to a decrease in eels. Chemical contaminants much distance, the species encounters many threats. may be affecting eel fertility. Governments, industry, and Many mature eels do not complete their journey down scientists are working together to decrease the threats that the St. Lawrence River and back to the Sargasso Sea. eels face at different points in their life cycles. 8 Parts of an Ecosystem Ecosystems can cover large areas of land or water, such as the boreal biotic the living parts of an forest system in Ontario. Ecosystems can also be small, such as a rotting ecosystem log or a pool of water. Every ecosystem has biotic and abiotic parts. abiotic the non-living parts Biotic refers to the living parts of an ecosystem. The biotic parts of an of an ecosystem ecosystem include plants, animals, and micro-organisms. Abiotic refers to the non-living parts of an ecosystem. The abiotic parts of an ecosystem include water, oxygen, light, nutrients, and soil. Learning Check Describe the ways in which the people’s use of trees on Easter Island was unsustainable. What is the two-part meaning of the word sustain? 3 Use the map in Figure 1.2 to explain how ruby-throated hummingbirds are dependent on more than one ecosystem. List some biotic parts of the ecosystem in which you live. American eels hatch in the Sargasso Sea in the Atlantic Ocean. The larvae migrate to the St. Lawrence River and the Great Lakes. Mature eels often spend 10 to 15 years in the Great Lakes before returning to the Sargasso Sea to reproduce and die. Your Turn How Can We Help the American Eel? 1. Why is the American eel an important part of the Commercial fishers are helping scientists capture ecosystem of the St. Lawrence River and Great Lakes? and tag large eels. 2. Identify different stakeholders affected by the Ontario Power Generation is shipping eels down the decline of the American eel (for example, commercial St. Lawrence and releasing them in Lac St. Pierre in fishers, Aboriginal peoples, workers in the power Quebec, so that the eels do not have to pass through industry). Write a short paragraph to describe the dam turbines. issue from the point of view of one of the The First Nations along the St. Lawrence River have stakeholders. agreed to stop all harvesting and work with the 3. Create a poster for a campaign to raise public Department of Fisheries and Oceans and other awareness about the American eel. Your poster should agencies to ensure this species is protected. highlight the importance of the eel to the health of the Hydro Quebec, New York Power Authority, and Ontario Great Lakes ecosystem and the historical significance Power Generation have built eel ladders at their St. of the American eel to Aboriginal peoples and Ontario's Lawrence River dams to help eels migrate upstream. fishing industry. 9  Biotic Characteristics of an Ecosystem The biotic characteristics of an ecosystem include all the living things, such as plants, animals, fungi, bacteria, and protists, in an ecosystem. They also include all the interactions among the living things in the ecosystem. Examples of such interactions, shown in Table 1.1, include symbiosis, predation, and competition. Table 1.1 Biotic Interactions Biotic Interaction How It Works Symbiosis Symbiosis is the interaction between members of two different species that live together in a close association. Although you cannot see any interaction from the surface, the mushrooms in the photograph help the nearby trees absorb water and nutrients from the soil. Masses of mushroom tissue surround the roots of the trees, increasing the area that the roots cover and thus increasing their absorption. The mushroom tissue also helps to prevent the roots from drying out. The mushrooms benefit as well. The mushrooms get food, in the form of sugar, produced by the trees. Predation Predation occurs when one organism consumes another organism for food. The organism that is consumed is called the prey. The organism that eats the prey is called the predator. The river otter shown in the photograph is a predator. Its prey includes fish, crabs, frogs, and turtles. The river otter is also prey for other predators, such as coyotes. In this way, organisms are linked together through the food chain. The relationship between predators and their prey can influence the population of both the predator and the prey, as well as affect the entire ecosystem in which they live. You will read more about predation later in this chapter and in Chapter 2. Competition Competition occurs when two or more organisms compete for the same resource, such as food, in the same location at the same time. The dandelions in the photograph compete with the grass for the same resources. The dandelions may block out light that the grass needs to survive. They may also soak up more water or nutrients from the soil, leaving less for the grass. Competing for resources takes energy. Energy expended on competition is energy that is taken away from other important life processes, such as growth and reproduction. Competition can influence the population size and success of a group of organisms. Sometimes, one group of organisms is outcompeted by another group. You will read more about competition and how it influences populations in Chapter 2. 10 Activity 1-2 What Symbol Would You Choose? The statues on Easter Island have probably become one 2. Design another symbol or image to represent a future of of the best-known symbols for the idea that cultural increased environmental awareness. short-sightedness can lead to unsustainable ecosystems. 3. Share your designs with your classmates. Sometimes symbols can be biotic factors. For example, the polar bear has recently been used as a symbol to Questions alert people to the consequences of global warming. 1. How did your designs differ from your classmates' Other times, a symbol may represent an abiotic factor, such as water or space. What symbol would you designs? choose to represent an environmental issue occurring 2. What symbol from our society would you choose to right now? represent our current relationship with the environment? Explain your choice. Materials construction paper tape or glue coloured markers Internet access scissors computer lab Procedure 1. Design a symbol or an image to represent the world's current environmental problems. Making a Difference In Grade 9, Yvonne Su discovered that her Newmarket school was not recycling because it lacked the resources. Yvonne felt a responsibility to do something. She and her friends, with the help of some teachers, decided to tackle the recycling themselves, so they started a recycling and environmental club. Yvonne has been involved in environmental activities ever since. "As Grade 9s, my friends and I didn't know where to turn to learn more about our planet. After speaking to some teachers, we found out that our greatest resources were right in front of us our science classes." The more Yvonne and her friends learned, the more they wanted to share their knowledge. They organized campaigns about environmental issues at their school. Then they took their campaigns to schools across Canada. Yvonne was named one of Canada's Top 20 Under 20 in 2007. She is now studying environmental science at the University of Guelph. What changes would you suggest making at your school to help the environment? 11  Abiotic Characteristics of an Ecosystem The abiotic characteristics of an ecosystem, described in Table 1.2, are as important as the biotic characteristics. The abiotic characteristics are the factors that living things need to survive. Table 1.2 Abiotic Characteristics of an Ecosystem Abiotic Characteristic Why It Is Important Effects on Sustainability Water All organisms need water Both natural processes and to survive. Plants take up human activities can affect the water through their roots. amount and quality of water in an Some animals need water ecosystem. Water sources can dry to help regulate their body out during long, hot periods with temperature. Animals also no rain. Chemicals from industries use water to get rid of and agriculture can contaminate wastes. Many organisms live water. in freshwater and saltwater ecosystems. Oxygen Many organisms, including Sometimes, as a result of human plants and animals, need activities, oxygen levels in water oxygen for their life can get so low that fish and other processes. Aquatic organisms organisms cannot survive. get oxygen from water. Light Plants and other organisms The amount of light that an need light for photosynthesis, ecosystem receives can vary. a life process in which Plants near the floor of a forest organisms produce their own may be shaded by taller trees. food. Light in an aquatic ecosystem can be affected by the amount of sediment in run off. Nutrients Plants and animals need Nutrient levels in an ecosystem nutrients, such as nitrogen can become unbalanced as a result and phosphorus, to grow. of human activities. Soil Soil provides nutrients for Top layers of soil, which contain plants and a habitat for many the most nutrients, can be washer micro-organisms. away if there is heavy rain or if tor many trees have been cut down. 12 Cycling of Matter and Earth's Spheres Hummingbirds consume water, insects, and nectar to survive. The water, insects, and nectar, as well as the hummingbird itself, are different Study Toolkit forms of living and non-living matter. The hummingbird uses the matter Word Families Make a word it consumes to fly, build muscle, reproduce, and carry out other life family web to show how the processes. Ecological processes move matter from the biotic and abiotic vocabulary words on this parts of an ecosystem, and back again, in continuous cycles. page are related. At any time, matter can occupy one of the four spheres that make up Earth. The hard part of Earth’s surface is the lithosphere, from the Greek word for stone. The salt water in the oceans and the fresh water on the lithosphere the hard part of continents form the hydrosphere. The Greek word hydro- means water. Earth's surface The layer of air above Earths surface is the atmosphere, from the Greek hydrosphere all the water word atmos, which means vapour. found on Earth, including lakes, oceans, and ground Figure 1.3 shows the lithosphere, hydrosphere, and atmosphere. In this water image of North Africa and Europe, the lithosphere is best represented atmosphere the layer of by Earth’s largest desert, the Sahara. The North Atlantic Ocean and the gases above Earth's surface Mediterranean Sea represent the hydrosphere, and the light from the Sun shows the thin layer of gases that make up the atmosphere. Earth's Biosphere The lithosphere, hydrosphere, and atmosphere are abiotic spheres that are found on other planets, as well as Earth. Mars has all three spheres, although its hydrosphere is mostly ice and its atmosphere has very little oxygen. There is a fourth sphere at Earth’s surface, however, that no other planet in the solar system is known to have—a biosphere. The biosphere is the living surface of Earth, but it is not separate from biosphere the regions of the abiotic spheres. After all, many life forms are found underground, in Earth where living organisms exist both fresh water and salt water, and in the atmosphere as well. Figure 1.3 In this image of Earth, all four spheres are visible. The biosphere is all around us. It exists everywhere you can see