Program Authors Dr Jay K Hackett Professor Emeritus of Earth Sciences University of Northern Colorado Dr Gerald F Wheeler Executive Director National Science Teachers Association Bank Street College of Education Dr Richard H Moyer New York, NY Professor of Science Education and Natural Sciences University of Michigan–Dearborn Contributing Authors Dr JoAnne Vasquez Sally Ride Science San Diego, CA Elementary Science Education Consultant NSTA Past President Member, National Science Board and NASA Education Board Mulugheta Teferi, M.A Principal, Gateway Middle School St Louis Public Schools St Louis, MO Dinah Zike, M.Ed Dr Sally Ride Lucille Villegas Barrera, M.Ed Elementary Science Supervisor Houston Independent School District Houston, TX Dr Stephen F Cunha Professor of Geography Humboldt State University Arcata, CA Dinah Might Adventures LP San Antonio, TX American Museum of Natural History Kathryn LeRoy, M.S New York, New York Executive Director Division of Mathematics and Science Education Miami-Dade County Public Schools, FL Contributing Writer Dr Dorothy J T Terman Ellen Grace Albuquerque, NM Science Curriculum Development Consultant Former K–12 Science and Mathematics Coordinator Irvine Unified School District, CA The American Museum of Natural History in New York City is one of the world’s preeminent scientific, educational, and cultural institutions, with a global mission to explore and interpret human cultures and the natural world through scientific research, education, and exhibitions Each year the Museum welcomes around four million visitors, including 500,000 schoolchildren in organized field trips It provides professional development activities for thousands of teachers; hundreds of public programs that serve audiences ranging from preschoolers to seniors; and an array of learning and teaching resources for use in homes, schools, and community-based settings Visit www.amnh.org for online resources Students with print disabilities may be eligible to obtain an accessible, audio version of the pupil edition of this textbook Please call Recording for the Blind & Dyslexic at 1-800-221-4792 for complete information B Published by Macmillan/McGraw-Hill, of McGraw-Hill Education, a division of The McGraw-Hill Companies, Inc., Two Penn Plaza, New York, New York 10121 Copyright © 2008 by Macmillan/McGraw-Hill All rights reserved No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, network storage or transmission, or broadcast for distance learning Science Content Standards for California Public Schools reproduced by permission, California Department of Education, CDE Press, 1430 N Street, Suite 3207, Sacramento, CA 95814 is a trademark of The McGraw-Hill Companies, Inc Printed in the United States of America ISBN 0-02-284377-9/3 (027/055) 10 09 08 07 06 Content Consultants Rick MacPherson, Ph.D Program Director The Coral Reef Alliance San Francisco, CA Bonnie J Brunkhorst, Ph.D Barbara Messmer Scott Hays Bret Harrison Roseville City School District K-8 Teacher (retired) Coffee Creek Elementary Washington Union School District Carmel USD Frank Ledesma Elementary Soledad USD Soledad, CA Kathy Jones Abraham Lincoln Elementary Simi Valley USD Simi Valley, CA Joy Peoples Riverside USD Elizabeth Ramsey Bel Air Elementary Andrew Rodarte Easterby Elementary Department of Fresno USD Geological Sciences, California State University Rhonda Simard San Bernardino, CA Franklin Elementary Franklin USD Hector Córdova Mireles, Ph.D Physics Department California State Polytechnic University Pomona, CA Editorial Advisory Board Gus Dalis, Ed.D Education Consultant Torrance, CA Jeri Starkweather Calwa Elementary Fresno USD Lauri Talbott Carr Elementary Torrance USD Chico USD Nancy Maguire Westpark Elementary Irvine, CA Bettina Pierce Elementary Science Specialist Irvine USD Vince Sipkovich Educator/Science Consultant/Writer Huntington Beach, CA Melissa Smith Dawn Vollmar Canyon Lake Middle School Foulks Ranch Elementary Lake Elsinore USD Elk Grove USD Lindsay Waterman Judith Sydner-Gordon Debbie Drab Alamo Elementary Long Beach USD Sandra S Wilbur Carolyn Fong Los Angeles USD Chaparral Elementary Capistrano USD Canfield Elementary School Los Angeles, CA Joyce Garcia Janet Yamaguchi La Seda Elementary Rowland USD Nancy Howe Martin Luther King Academy Alisal USD Linda D King Principal, Muscoy Elementary San Bernardino City USD Michael Harris Teacher Reviewers Chico USD Vicky Ann Buckley Karen Kohn Helen Logan Hays Las Virgenes USD K-8 Teacher (retired) Ukiah USD Coffee Creek Elementary School District Carmel USD U.S Grant Elementary Colton Joint USD Colton, CA Donna Lowe Cherryland Elementary Hayward USD Jerrie Martin La Veta Elementary Orange USD Orange, CA Christina Lambie Highland Elementary West Contra Costa USD Richmond, CA Alice Moomjean Cortada Elementary El Monte USD El Monte, CA Michelle Orgon Needham Intermediate Lodi USD Lodi, CA Sue Parsons Richard Bard Elementary Hueneme USD Navelencia Middle School Pt Hueneme, CA Reedley, CA Task Force Escondido USD Joanne Hemmings Jennifer Weibert Discovery Science Center Santa Ana, CA Susan Gomez Zwiep Assistant Professor Science Education Cal State University Diane Carnahan Long Beach K–12 Alliance/WestEd David M Harris Dennis Hatland Sharon Pendola St Alban’s Country Day School Roseville, CA Lisa Robinson Marengo Elementary South Pasadena USD South Pasadena, CA Roberta Sanchez Lindberg Schweitzer Elementary San Diego USD San Diego, CA Naomi Griswold Rio Hondo Elementary Downey USD Downey, CA NBCT Los Angeles USD iii ;OYS=PaS`dObW]\a /aYO?cSabW]\ 4]`[O6g^]bVSaWa BSabG]c`6g^]bVSaWa 2`Oe1]\QZcaW]\a @SacZba Ac^^]`b6g^]bVSaWa iv @SacZba2]