MHE_Rdg_Wonders_LvRdr_G5_Beyond_U2W3_08.pdf

BiographyPAIREDREADGolden Applesby Jocelyn CranefieldGreen RevolutionGreen RevolutionNormanNormanBorlaugBorlaugand theand theProgram:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60CV_CR14_LR_G5_U2W3L60_B_118723.indd 2CV_CR14_LR_G5_U2W3L60_B_118723.indd 226/01/12 2:55 PM26/01/12 2:55 PMASTRATEGIES&SKILLSComprehensionStrategy:RereadSkill:SequenceVocabulary StrategyGreek and Latin SuffixesVocabularybehaviors,disappearance,energetic,flurry,migrate,observation,theory,transformedContent StandardsScienceScience as InquiryPhotography Credit:(c)Micheline Pelletier/Sygma/CORBIS,(t and b)Tinke Hamming/Ingram Publishing.*The total word count is based on words in the running text and headings only.Numerals and words in captions,labels,diagrams,charts,and sidebars are not included.Word Count:1,848*Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60Copyright The McGraw-Hill Companies,Inc.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.Send all inquiries to:McGraw-Hill EducationTwo Penn PlazaNew York,New York 10121ISBN:978-0-02-118722-5MHID:0-02-118722-3Printed in the United States.1 2 3 4 5 6 7 8 9 DOC 15 14 13 12 11 10IFCIBC_CR14_LR_G5_U2W3L60_B_118723.indd 2IFCIBC_CR14_LR_G5_U2W3L60_B_118723.indd 226/01/12 2:56 PM26/01/12 2:56 PMby Jocelyn CranefieldGreen RevolutionGreen RevolutionNormanNormanBorlaugBorlaugand theand theEssential QuestionHow do we investigate questions about nature?PAIREDREADChapter 1An Iowa Boy.2Chapter 2Borlaug Goes to Mexico.5Chapter 3A Breakthrough.8Chapter 4More Wheat for the World.12Respond to Reading.15Golden Apples.16Glossary/Index .19Focus on Science.20Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60Tinke Hamming/Ingram Publishing001_008_CR14_LR_G5_U2W3L60_B_118723.indd 1001_008_CR14_LR_G5_U2W3L60_B_118723.indd 110/02/12 9:49 AM10/02/12 9:49 AMNorman Borlaug and his friends were on their way to school when suddenly they were caught in a blizzard.Norman and his friends walked to school in almost all weather,but a neighbor would take them on a horse and sled during very bad storms.However,on this day,the blizzard came up very fast.Norman soon became exhausted from walking in the wind and cold.He decided to lie down in the deep,soft snow,telling the others he could not go on.His cousin Sina grabbed him,shouting that he had to keep moving.Her behavior made him get back up and continue on his way to school.By not letting him stop and sleep in the blizzard she had saved his life.Years later,Norman said that Sina inspired him by refusing to let him give up that day.An Iowa BoyAn Iowa BoyChapter 1Norman had to walk to school in all kinds of weather.Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:602(bkgd)Tinke Hamming/Ingram Publishing,(b)Richard Mack/Workbook Stock/Getty Images001_008_CR14_LR_G5_U2W3L60_B_118723.indd 2001_008_CR14_LR_G5_U2W3L60_B_118723.indd 210/02/12 9:49 AM10/02/12 9:49 AM3Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60(g)ggg,()ygNorman Borlaug was born on his grandparents farm in Saude,Iowa,in 1914.He was the eldest of four children.People in this farming community relied on the land to survive,and from a young age Norman had work to do.He helped his family to raise cattle,pigs,and chickens,and to grow oats andcorn.At his one-room country school,the children began each day by singing“The Iowa Corn Song.”In the winter,there were 16 students at the school,but in the summer,enrollment dropped to only 10 or 12.Theolder boys were unable to attend school because they were needed to help harvest the crops instead.Norman Borlaug was made a member of the National Wrestling Hall of Fame in 1992.GIVING 105%During high school,Norman took up baseball and wrestling.He achieved state-wide renown as a competitive wrestler.His wrestling coach always encouraged him to“give 105%.”This idea helped him develop a toughness and strength that he would call on later in life.Image courtesy of the University of Minnesota Archives,University of Minnesota-Twin Cities001_008_CR14_LR_G5_U2W3L60_B_118723.indd 3001_008_CR14_LR_G5_U2W3L60_B_118723.indd 310/02/12 9:49 AM10/02/12 9:49 AMWhen Norman finished high school,his grandfather encouraged him to keep studying.Norman enrolled at the University of Minnesota,taking odd jobs to help pay his way.This was during the Great Depression.Norman was shocked to meet many desperate,hungry people who had lost their jobs,savings,and property.One day,he heard a scientist at the university talk about microscopic fungus spores called rust,which feed on crops and destroy them.The scientist,Dr.Elvin Stakman,described rust as a“shifty enemy.”Rust spreads by releasing microscopic spores into the wind,which helps it to travel around the world.Dr.Stakman argued that if science could discover a way to help plants resist rust,world hunger would be reduced.Norman was instantly hooked on the idea.He went on to study with Dr.Stakman.This wheat stem has rust.Microscopic rust spores are picked up by the wind and carried from plant to plant.Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:604Ted Streshinsky/CORBIS001_008_CR14_LR_G5_U2W3L60_B_118723.indd 4001_008_CR14_LR_G5_U2W3L60_B_118723.indd 410/02/12 9:49 AM10/02/12 9:49 AMBorlaug Goes to MexicoWhen he finished college in 1942,Norman Borlaug got a job with the DuPont chemical company.But in 1944,his former teacher,Dr.Stakman,encouraged him to join a project working on solving Mexico s food shortage problem.Mexico needed more food crops for its growing population.Borlaug s job was to lead a team of scientists and farmers.Theyneeded to figure out how to grow more wheat on each acre of farmland,increasing the land s yield.YIELDThe only part of wheat used for food is the seed,or grain.Yield is the amount of grain that comes from an area planted with wheat.It is usually expressed as U.S.bushels per acre.One bushel of wheat weighs about 60 pounds.The yield depends on how many heads of wheat there are,the number of seeds,and the size of the seeds.The better the yield,the more people can be fed.The head of the wheat plant makes up its yield.Borlaug Goes to MexicoChapter 2seedsstemleafrootshead5Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60(t)Tinke Hamming/Ingram Publishing,(b)illustration:Peter Campbell001_008_CR14_LR_G5_U2W3L60_B_118723.indd 5001_008_CR14_LR_G5_U2W3L60_B_118723.indd 510/02/12 9:49 AM10/02/12 9:49 AMThere was another problem:a significant amount of Mexico s wheat crop was being ruined by rust fungus.Borlaug needed to breed wheat that was resistant to rust as quickly as possible.This process would take 10 to 12 years using normal methods.He needed to find a way to speed up the process.Borlaug started his work at the Yaqui(YAH-kee)Valley Experiment Station in Sonora,Mexico.The research station was in disrepair,with broken windows and no power,but the conditions in the valley were perfect for growing wheat.The days were warm and sunny,the soil was rich and fertile,and the land was irrigated.Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:606001_008_CR14_LR_G5_U2W3L60_B_118723.indd 6001_008_CR14_LR_G5_U2W3L60_B_118723.indd 610/02/12 9:49 AM10/02/12 9:49 AMNorman Borlaug had a theory about how to double the rate of breeding wheat by growing it all year round,but his theory meant breaking with tradition.At that time,scientists normally bred plants at a single site.This made it easy to control the growing conditions and compare the results of experiments.They also thought that newly harvested seeds need a rest to store energy before being replanted.So Borlaug s ideas were very innovative.The Yaqui Valley was a good place to grow wheat in the winter,but in the summer it was too hot.Summer temperatures there reach more than 100 degrees Fahrenheit.If Borlaug could find somewhere else to grow wheat in the summer,he could run his experiments all year long.This might make all the difference in his race to find a solution.The Yaqui Valley is sometimes called the home of the“green revolution”because of Norman Borlaugs work there.Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:607Ted Streshinsky/CORBIS001_008_CR14_LR_G5_U2W3L60_B_118723.indd 7001_008_CR14_LR_G5_U2W3L60_B_118723.indd 710/02/12 9:49 AM10/02/12 9:49 AMA BreakthroughNorman Borlaug traveled around Mexico,taking note of different climates.He was looking for places where wheat would grow in the summer.Hundreds of miles away,in the cold mountain climate of the south,he found two sites near each other that seemed perfect:Toluca(toh-LEW-kah)Valley and Chapingo(chah-PEEN-goh).Chapter 3A BreakthroughNow Borlaug had two different growing seasons to work with.In the winter,he could grow wheat at the Yaqui Valley site in the north.In the summer,he could grow it at the TolucaValley and Chapingo sites in the south.WHEAT-BREEDING SITES IN MEXICOYaqui ValleyToluca ValleyChapingoMexico CityGulf of MexicoPacific OceanUNITUNITUNITUNITUNITNITUNITUNININ NUNED SE EDED DED SED SED SED D S S STATETATETATETATETATETATETA E EA AS S S S S OF OF AOF AOF AOFOF AOAF AOF AOOF A AF AOF A AOAMERIMERIMERIMERIMERMERIMERIMERMERMERIERE IMCACACACACACACA AC C CA ABELIZEGUATGUATGUATGUATGUATGUATGUATGUATGUATUATGUATUG GUATUAUEMALEMALEMALEMALEMALEMALEMALEMALEMEMMMALEMALALA AEMALA A A A A A A A A A A(t)Tinke Hamming/Ingram Publishing,(b)illustration:Peter Campbell8Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60001_008_CR14_LR_G5_U2W3L60_B_118723.indd 8001_008_CR14_LR_G5_U2W3L60_B_118723.indd 810/02/12 9:49 AM10/02/12 9:49 AMAs the years went on,Borlaug and his energetic team shuttled,or moved,many generations of plants back and forth between the northern and southern sites.He called this new system“shuttle breeding.”With the help of local farmers,Borlaug set about crossbreeding different kinds of wheat.Each time a new generation grew in the Yaqui Valley,he spent hours continuing his observation of the plants.He took notes on their size,how fast they grew,and their resistance to disease.He picked the best plants and crossed them with other successful plants,creating a new generation to grow at the southern sites.Borlaug s theory had proved correct.By moving plants between sites with different growing seasons,he could do twice as many breeding experiments.CROSSBREEDINGIn crossbreeding,scientists choose plants with features they want to combine.One plant might be fast growing and another might be resistant to disease.Scientists use the pollen from one type of plant to pollinate the other plant.Then scientists combine these plants to create a new variety,called a hybrid.The hybrid has both traits of the parent plants.Borlaug(third from left)with a group of Mexican farmers in a wheat field.Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:609Courtesy CIMMYT International Maize and Wheat Improvement Center009_015_CR14_LR_G5_U2W3L60_B_118723.indd 9009_015_CR14_LR_G5_U2W3L60_B_118723.indd 920/02/12 1:07 PM20/02/12 1:07 PMAll this testing helped Borlaug and his team to finally develop a strain of wheat that could resist disease.While the team was excited about the disappearance of the rust,they found another problem.The new plants produced so much wheat that they often bent over from the weight of their own grain.They were too heavy and tall!Borlaug started using shorter plants,called dwarfs,in the breeding program.The strong,thick stems of the dwarf wheat plants helped them to stay upright.Even better,they also produced more grain.By crossing these dwarf plants with the taller wheat,Borlaug s team was able to solve the problem.They developed a new variety of wheat that was disease resistant and short stemmed,and had a higher yield.Norman Borlaug shows two varieties of wheat.10Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60Associated Press009_015_CR14_LR_G5_U2W3L60_B_118723.indd 10009_015_CR14_LR_G5_U2W3L60_B_118723.indd 1020/02/12 1:07 PM20/02/12 1:07 PMNorman Borlaug s work in Mexico took more than 15 years,but the project was a huge success.In the end,Borlaug and his team bred more than 40 short,rust-resistant strains of high-yield wheat.When the new strains were grown with fertilizer,they produced two to three times more grain than normal wheat.The breeding across sites had another benefit,too.The new wheat had been grown in different climates,with different numbers of daylight hours,making it tough and adaptable.Borlaug realized the high-yield semi-dwarf variety could be grown in many places and in varying conditions.This was good news for the rest of the world.After the new wheat strains were planted throughout Mexico,the wheat yield increased from approximately 250,000 tons to approximately 2,500,000 tons.Thats a ten-fold increase over a period of 20 years!Wheat yield in 1945:about 250,000 tonsWheat yield in 1965:about 2,500,000 tonsMEXICOS WHEAT YIELDS BEFORE AND AFTER THE HIGH-YIELD SEMI-DWARF VARIETY 11Program:CR 14Component:LRG5 U2 W3 BPDFVendor:Learning MediaLevel:60Illustration:Peter Campbell009_015_CR14_LR_G5_U2W3L60_B_118723.indd 11009_015_CR14_LR_G5_U2W3L60_B_118723.indd 1120/02/12 1:07 PM20/02/12 1:07 PMMexicoPakistanIndiaAFRIAFAFRIAFRIAFRIAFRIAFRAFRIAFRIAFAFRIAFRIAFAFRIFRAFRAFRIAFRIAFRIAFRIAFRAFRIAFRIAFRAFRIA A R RFRIA A AF F F FA A ACACACACACACACACACAC CACACACACACACACACACACA ACACA A AC CASIAASIAASIAASIAASIAASIAASIAASIAASIAASIAASIAASIAASIAASIASIASIAIAASIASIAASIAASIAASIAIAIA AASIAASIAIASIAASIASEUROEUROEUROEUROEUROEUROEUROEUROEUROEUROEUROUROEUROEUROOEUROEUROEUROROOOUROUROEUROEUROOOREUROOUROOPEPEPEPEPEPEPEPEPEPEPEPEPEPEPEPEPEPEPEPE EPEPEPE E E E E ESOUTSOUTSOUTSOUTSOUTS SOUTSOUTSOUTSOUTS SOUTSOUTSOUTSOUTSOUTOUTOUTUT TSOUTSOSOUTSOUTOUTSOUTSOUTSOUTUOUTSOUTUT TUTUT T TU H H H H H H H H H H H H H H H H H H H H H H H H H H H H HAMERAMERAMERAMEAMERAMERAMERAMERAMEAMERAMERAMEAMERAMERAMERE ERMERAMERERAMERA AMERAMERAME ERMERMER R RMARM R R R R RICAICAICAICAICAICICAICAICAICAICAICA ACAICAICAICICACACAC CAI AICAICI ICICICAICICAI IC CAI ICIC CACIC CNORTNORTNORTNORTNORTNORTNORTNORTNORTNORTNORTNORTNORTNORTNORTONORTONORTNORTNONORTNONORTORTORTOORTRO TNR H H H H H H H H H H H H H H H H H H H HAMERAMERAMEAMERAMERAMERAMERA AMERAMERAMERAMERAMERAMEAMERAMERAMERAMEAMERAMERMEAMERA A ARMER RAMERA AR R RICAICAICAICAICAICAI ICAICAICAICAICAICAICAICA AICACAICAI ICAICA AC CAI A AAtlantic OceanIndian OceanPacificOceanMEXICO,INDIA,AND PAKISTANMore Wheat for the WorldIn 1965,Borlaug shipped 450 tons of the new wheat seeds from Mexico to India and Pakistan.In the 1960s,Norman Borlaug turned his attention to an even bigger problem.India and Pakistan were struggling to produce enough food for their growing populations.Many scientists believed that millions of people could starve if food produc