Setting the Standard for Excellence, Accuracy, and Innovation

C AMPBELL
M M




BIOLOGY
M M M



TWELFTH
M



M
M



M
M



EDITION M
M




Lisa A. Urry
M M Michael L. Cain
M M Steven A. Wasserman
M M

MILLS M COLLEGE, M NEW M MEXICO M STATE M UNIVERSITY M OF M CALIFORNIA,
OAKLAND, M CALIFORNIA UNIVERSITY M SAN M DIEGO




Rebecca B. Orr
Peter V. Minorsky
M M
M M
COLLIN M COLLEGE, M PLANO, M TEXAS
MERCY M COLLEGE, M DOBBS M
FERRY, M NEW M YORK

,Director, M Global M Higher M Ed M Content M Management Project M Manager: M Katie M Cook
M and M Strategy, M Science M & M Health M Sciences: M Content M Producers, M Mastering M Biology: M Kaitlin
Jeanne M Zalesky M Smith, M Ashley M Gordon

Manager, M Higher M Ed M Global M Content M Strategy, M Supervising M Media M Producer: M Tod M Regan
Life M Sciences: M Joshua M Frost Media M Producer: M Ziki M Dekel
Associate M Content M Analyst: M Chelsea M Noack Full-Service M Vendor: M Integra M Software M Services, M Inc.
Editorial M Assistant: M Ashley M Fallon Design M Manager: M Mark M Ong
Director, M Higher M Ed M Product M Cover M & M Interior M Designer: M Jeff M Puda
Management, M Life M Sciences: M Illustrators: M Lachina M Creative
Michael M Gillespie
Rights M & M Permissions M Project M Manager: M Matt M
Product M Manager: M Rebecca M Berardy M Schwartz Perry, M SPi M Global
Managing M Producer: M Michael M Early Rights M & M Permissions M Manager: M Ben M Ferrini
Senior M Content M Producer: M Lori M Newman Photo M Researcher: M Maureen M Spuhler
Director, MContent MDevelopment M& M Product M and M Solutions M Specialist: M Kelly M Galli
Partner M Relationships: M Ginnie M
M Senior M Product M Marketing M Manager: M Alysun M
Simione M Jutson
Estes M Manufacturing MBuyer: MStacey M
Supervising M Editors: M Beth M N. M Winickoff, M Pat M
Weinberger, MLSC
Burner
Communications
Senior M Developmental M Editors: M John M Burner, M Mary M
Cover M Photo M Credit: M Robert M
Ann M Murray, MHilair MChism, MAndrew MRecher, M
Mary MHill Rohrbaugh/Rohrbaugh M Photography
Specialist, M Instructional M Design M and M
Development:
Sarah M Young-Dualan
Senior M Content M Developer, M Mastering M Biology:
Sarah M Jensen

Copyright M © M 2021, M 2017, M 2014 M by M Pearson M Education, M Inc. M or M its M affiliates, M 221 M River M Street, M
Hoboken, M NJ M 07030. M All M Rights M Reserved. M Manufactured M in M the M United M States M of M America. M This M
publication M is M protected M by M copyright, M and M permission M should M be M obtained M from M the M publisher M prior M
to M any M prohibited M reproduction, M storage M in M a M retrieval M system, M or M transmission M in M any M form M or M by M
any M means, M electronic, M mechanical, M photocopying, M recording, M or M otherwise. M For M information M
regarding M permissions, M request M forms, M and M the M appropriate M contacts M within M the M Pearson M Education M
Global M Rights M and M Permissions M department, M please M visit M www.pearsoned.com/permissions/.
Acknowledgments Mof Mthird-party Mcontent Mappear Min Mthe MCredits Msection M(beginning M on Mpage MCR-1), M
which M constitutes M an M extension M of M this M copyright M page.
PEARSON, M ALWAYS M LEARNING, M MasteringTM M Biology, M and M BioFlix® M are M exclusive M trademarks M

owned M by M Pearson M Education, M Inc. M or M its M affiliates M in M the M U.S. M and/or M other M countries.
Unless M otherwise M indicated M herein, M any M third-party M trademarks M that M may M appear M in M this M work M are M the M
property M of M their M respective M owners M and M any M references M to M third-party M trademarks, M logos M or M other M trade
M dress M are M for M demonstrative M or M descriptive M purposes M only. M Such M references M are M not M intended M to M imply

M any M sponsorship, M endorsement, M authorization, M or M promotion M of M Pearson’s M products M by M the M owners M of M

such M marks, M or M any M relationship M between M the M owner M and M Pearson M Education, M Inc. M or M its M affiliates, M
authors, M licensees M or M distributors.

Library M of M Congress M Cataloging-in-Publication M Data
Names: M Urry, M Lisa M A., M author. M | M Cain, M Michael M L. M (Michael M
Lee), M author. M | M Wasserman, M Steven M Alexander, M author. M | M
Minorsky, M Peter M V., M author. M | M Orr, M Rebecca M B., M author. M | M
Campbell, M Neil M A., M Biology.
Title: M Campbell M biology M / M Lisa M A. M Urry, M Michael M L. M Cain, M
Steven M A. M Wasserman, M Peter M V. M Minorsky, M Rebecca M B. M
Orr, M Neil M A. M Campbell.
Description: M Twelfth M edition. M | M New M York, M NY M : M Pearson, M 2020. M | M
Includes M index. M Identifiers: M LCCN M 2019039139 M | M ISBN M 9780135188743
M (hardcover) M |

ISBN M 9780135988046 M (ebook)
Subjects: M LCSH: M Biology.
Classification: M LCC M QH308.2 M .C34 M 2020 M | M DDC M
570—dc23 M LC M record M available M at M
https://lccn.loc.gov/2019039139


ScoutAutomatedPrintCode

, ISBN M 10: M 0-135-18874-1; M ISBN M 13: M 978-0-135-18874-3 M (Rental M Edition)
ISBN M 10: M 0-136-62344-1; M ISBN M 13: M 978-0-136-62344-1 M (Instructor M Review M Copy)
www.pearson.com

, Setting the Standard for Excellence,
M M M M M




Accuracy, and Innovation M M




Campbell Biology, 12th Edition, delivers an authoritative, accurate,
M M M M M M M M


current, and pedagogically innovative experience that helps students make
M M M M M M M M M


connections so they learn and understand biology. This edition presents new,
M M M M M M M M M M


Mengaging visual and digital resources that meet demonstrated student
M M M M M M M M M


needs.