CorrectionKey B DO NOT EDIT--Changes Must Be Made Through .
CHAPTER9Big IdeaFrontiers ofBiotechnologyAdvances in biotechnology and the study ofgenomes allow scientists to manipulate DNA and combinethe genes of multiple organisms, and may provide newmedical treatments in the future.9.1Manipulating DNA9.2 Copying DNA6h, 9C3F, 6H, 9C9.3 DNA Fingerprinting9.4 Genetic Engineering6h3D, 6h9.5 Genomics and Bioinformatics6hData AnalysisConstructing Histograms2g9.6 Genetic Screening and GeneTherapy3D, 6hHMDScience.comONLINE LabsModeling Forensics QuickLab Modeling Plasmids and RestrictionEnzymes Modeling Genetic Engineering Genetic Screening Genetic Engineering 252 Unit 3: GeneticsDNA Fingerprinting Analysis of DNA Restriction Fragment Size Virtual Lab Gel Electrophoresis Virtual Lab Bacterial Transformation Video Lab Protein Detection Video Lab DNA Fingerprint Analysis (t) Getty ImagesOnline Biology
QHow canbiotechnologyreunite families?A natural disaster strikes. Families are separated. One application of biotechnology canhelp bring the families back together. DNAfingerprinting can identify people at thegenetic level. And it allowed the child pictured here, called Baby 81 by rescue workers,to be reunited with his parents months aftera tsunami, or tidal wave, devastated manyparts of Southeast Asia.READI N G T o o lb o xThis reading tool can help you learn the material in the following pages.USING LANGUAGEAnalogies Analogies compare words with similarrelationships. You can write analogies with words or withcolons. For example, the analogy “up is related to down inthe same way that top is to bottom” can be written “up :down :: top : bottom.” To answer an analogy problem, youmust figure out how the words are related. In thisexample, up is above down, and top is above bottom.Your TurnUse information found in prior chapters to complete thefollowing analogy:transcription : RNA :: translation :Chapter 9: Frontiers of Biotechnology253
9.1 Manipulating DNA6h, 9cVOCABULARYrestriction enzymegel electrophoresisrestriction map6H describe howtechniques such as DNAfingerprinting, genetic modifications,and chromosomal analysis are usedto study the genomes of organismsand 9C identify and investigate therole of enzymesKey ConceptBiotechnology relies on cutting DNA at specificplaces.MAIN IDEASScientists use several techniques to manipulate DNA.Restriction enzymes cut DNA.Restriction maps show the lengths of DNA fragments.Connect to Your WorldMany applications of genetics that are widely used today were unimaginable just 30years ago. Our use of genetics to identify people is just one example. Biotechnologyand genetics are used to produce transgenic organisms and clones. They are used tostudy diseases and evolution. They are used to produce medical treatments forpeople with life-threatening illnesses. Through many years of research and a combination of many kinds of methods, advances in biotechnology seem to happen on adaily basis.MAIN IDEA6HScientists use several techniques tomanipulate DNA.R E A D I N G TO O L B oxTAKING NOTESUse a supporting main ideaschart to organize your noteson ways in which DNA ismanipulated.Cutting DNARestriction enzymes cut DNA.Gel electrophoresis . . . By the middle of the 1950s, scientists had concluded that DNA was the geneticmaterial. Watson and Crick had determined the structure of DNA. Yet thefield of genetics as we know it today was just beginning. For example, even thegenetic code that you just learned about was not fully understood until theearly 1960s. Since that time, scientists have developed a combination ofmethods to study DNA and genes.DNA is a very large molecule, but it is still just a molecule. It is far toosmall to see, and you cannot pick it up or rearrange it with your hands. Therefore, scientists must be able to work with DNA without being able to see orhandle it directly. Chemicals, computers, and bacteria are just a few of thetools that have allowed advances in genetics research.Artificial nucleotides are used to sequence genes. Artificial copies of genesare used to study gene expression. Chemical mutagens are used to changeDNA sequences. Computers analyze and organize the vast amounts of datafrom genetics research. Enzymes, often from bacteria, are used to cut and copyDNA. Bacteria also provide one of the ways in which genes are transferredbetween different organisms. Throughout this chapter, you will learn aboutsome of the techniques used in biotechnology, as well as some of its applications. You likely have heard of genetic engineering, DNA fingerprinting, andcloning, but how are they done? In many cases, one of the first steps in biotechnology and genetics research is to precisely cut DNA.Infer Why might so many different methods be needed to study DNA and genes?254Unit 3: Genetics
MAIN IDEA9CRestriction enzymes cut DNA.Why would scientists want to cut DNA? To answer thatquestion, you have to remember that a gene is a sequenceof DNA nucleotides, and that a chromosome is one longDNA molecule. A whole chromosome is too large forscientists to study a particular gene easily, so theyhad to find a way to get much smaller pieces ofDNA. Of course, slicing a chromosome into pieces is notas simple as picking up the molecule and cutting it with apair of scissors. Instead, scientists use enzymes that act as molecular “scissors.” These enzymes, which slice apart DNA, come from manytypes of bacteria.Bacterial cells, like your cells, can be infected by viruses. As protectionagainst these invaders, bacteria produce enzymes that cut up the DNA of theviruses. As figure 1.1 shows, a DNA molecule can be cut apart in several placesat once by several molecules of a restriction enzyme, or endonuclease.Restriction enzymes are enzymes that cut DNA molecules when they identifyspecific nucleotide sequences. In fact, any time the enzyme finds that exactDNA sequence, it cuts the DNA molecule. The sequence of nucleotides that isidentified and cut by a restriction enzyme is called a restriction site. Theseenzymes are called restriction enzymes because they restrict, or decrease, theeffect of the virus on the bacterial cell.There are hundreds of known restriction enzymes. Different restrictionenzymes will cut the same DNA molecule in a variety of ways. For example,one restriction enzyme may find three of its restriction sites in a segment ofDNA. Another restriction enzyme might find six of its restriction sites in thesame segment. Different numbers of fragments with different lengths result.As you can see below, two different restriction enzymes can cut the samestrand of DNA in very different ways.Restriction Enzyme 1Restriction Enzyme 2restriction sites Torunn Berge/Photo Researchers, Inc.DNAThe DNA is cut into four fragments.Figure 1.1 A restriction enzyme(blue peaks) from an E. coli bacterium helps protect against virusesby cutting DNA (red). This cutting“restricts” the effect of a virus ona bacterium. (colored 3D atomic forcemicrograph; magnification 63,0003)restriction sitesDNAThe DNA is cut into seven fragments.Restriction enzymes recognize nucleotide sequences that are between fourand eight base pairs long, and then cut the DNA. Some enzymes make cutsstraight across the two strands of a DNA molecule. These cuts leave behindfragments of DNA that end in what are called “blunt ends.”Chapter 9: Frontiers of Biotechnology255
BiologyHMDScience.comFIGURE 1.2 Restriction Enzymes Cut DNAGO ONLINESome restriction enzymes leave behind nucleotide tails, or “sticky ends,”when they cut DNA.DNARestriction Enzymesrestriction sitesA restriction enzymecalled Taq cuts DNAwhen it finds itsrestriction site. Taq ’srestriction site isTCGAAGCTC G AstickyendTC G ATstickyendTA G CTA G CInfer How would the above illustration change if Taq left behind blunt ends9Crather than sticky ends when it cuts DNA?CONNECT TODNA Base PairsIn the chapter From DNA toProteins you learned that DNAnucleotides match up bycomplementary base pairing. Aalways pairs with T, and C alwayspairs with G.Other restriction enzymes, as shown in figure 1.2, make staggered cuts thatsequence for TaqIleave tailsrecognitionof free DNAbases on each side of the cut. These nucleotide tails ofthe cut DNA strands are called “sticky ends.” Sticky ends are like tiny pieces ofsticky endsT toT theirA A oppositeGVelcro that are readyto hook onsides. If two pieces of DNAwith sticky endsandcomplementarybasepairscomeclose to each other, theCCtwo segments of DNA will join by hydrogen bonding. Because of this characG A restrictionA T Tsticky endsteristic of DNA,enzymesthat leave sticky ends when they cut DNAare often used in biotechnology, as you will learn in Section 4.Summarize How do different restriction enzymes produce different DNA9Cfragments from the same DNA molecule?MAIN IDEA6H, 9CRestriction maps show the lengths of DNAfragments.VIRTUAL LabHMDScience.comGO ONLINEGel Electrophoresis256Unit 3: GeneticsAfter a long DNA molecule has been cut by restriction enzymes into manysmaller fragments, several things can be done with the DNA. For example, theDNA sequence of a gene can be studied, or a gene cut out from the DNA canbe placed into the DNA of another organism. But before anything else can bedone, the DNA fragments have to be separated from one another. The fragments are sorted according to their sizes by a technique called gel electrophoresis (ih-lehk-troh-fuh-ree-sihs).In gel electrophoresis, an electrical current is used to separate a mixture ofDNA fragments from each other. A sample of DNA is loaded into a gel, whichis like a thin slab of hard gelatin. A positive electrode is at one end of the gel.At the other end is a negative electrode. Because DNA has a negative charge,
Eurelios/Phototakedirection of traveldirection of travelthe fragments move toward the positive electrode, or thepositively charged pole. The gel also has tiny pores running through it. The pores allow small molecules to movequickly. Larger molecules cannot easily move through thegel and they travel more slowly. Therefore, the length of aDNA fragment can be estimated from the distance ittravels through a gel in a certain period of time. As shownFigure 1.3 Gel Electrophoresisin figure 1.3, DNA fragments of different sizes appear asA segment of DNA is cut with a restriction enzyme intodifferent bands, or lines, on a gel. The pattern of bands onfragments of different lengths.the gel can be thought of as a map of the original strand ofDNA sampleDNA. Restriction maps show the lengths of DNA fragDNA samplements between restriction sites in a strand of DNA.The bands on a gel indicate only the lengths of DNADifferent sizes of DNA fragments show up as bands on afragments. Alone, they do not give any information aboutgel. Smaller fragments move farther down the gel.the DNA sequences of the fragments. Even though restricRestriction map on gelDNA fragmentstion maps do not directly show the makeup of a fragmentRestriction map on gelDNA fragments–of DNA, the maps are very useful in genetic engineering,–which you will read about in Section 4. They can also beused to study gene mutations. How? First, a mutation mayadd or delete bases between restriction sites, which wouldchange the lengths of DNA fragments on a gel. Second, amutation may change a restriction site, and the DNAwould not be cut in the same places.Suppose, for example, that when a normal allele of agene is cut by a restriction enzyme, five DNA fragments appear as five different bands on a gel. Then, when a mutant allele of the same gene is cut with the sameenzyme, only three bands appear. Comparisons of restriction maps can help diagnose genetic diseases, as you will see in Section 6. Arestriction map from a person’s DNA can be compared with a restriction mapfrom DNA that is known to be normal. If the restriction maps differ, it is anindication that the person has inherited a disease-causing allele of the gene.Synthesize How are restriction enzymes used in making restriction maps?9CSelf-check Online9.1Formative AssessmentReviewingMain Ideas1. List four ways in which scientists can6Hmanipulate DNA.2. What determines how DNA will becut by a restriction enzyme?9C3. How does gel electrophoresisseparate DNA fragments from each6Hother?Critical thinking4. Apply Suppose you cut DNA. Youknow that you should find four DNAfragments on a gel, but only threeappear, and one fragment is verylarge. Explain what happened.HMDScience.comGO ONLINECONNECT TOMutations6. Would a mutation in a genealways be detectable byusing restriction maps? Why6Hor why not?5. Synthesize What is the relationshipbetween restriction sites and a6Hrestriction map?Chapter 9: Frontiers of Biotechnology257
!enilnO!That’s z ingA maVideo InquiryCoral Colds Find out howcorals get sick and how thepathogens compare tothose that infect humans.258online biologyHMDScience.comWebAnimal Cloning eview the risks and benefits ofRmaking animal clones. Then make arecommendation regarding the bestuse of funds for animal cloningprojects.VIRTUAL LabGel Electrophoresis Use gelelectrophoresis to make theDNA fingerprint of a personwho committed a crime.Then decide which suspect’sDNA matches the DNAfound at the crime scene.(c) AP Photo/Pat SullivanG
9.2 Copying DNA3f, 6H, 9CVOCABULARYpolymerase chain reaction(PCR)primer3F research and describethe history of biology andcontributions of scientists;6H describe how techniques such asDNA fingerprinting, geneticmodifications, and chromosomalanalysis are used to study thegenomes of organisms; 9C identifyand investigate the role of enzymesKey Concept Thepolymerase chain reaction rapidly copiessegments of DNA.MAIN IDEASPCR uses polymerases to copy DNA segments.PCR is a three-step process.Connect to Your WorldForensic scientists use DNA from cells in a single hair at a crime scene to identify acriminal. Doctors test a patient’s blood to quickly detect the presence of bacteriathat cause Lyme disease. Scientists compare DNA from different species to determine how closely the species are related. However, the original amount of DNA fromany of these sources is far too small to accurately study. Samples of DNA must beincreased, or amplified, so that they can be analyzed.MAIN IDEA3F, 6H, 9C Mark Robert HalperPCR uses polymerases to copy DNA segments.FIGURE 2.1 Kary Mullis came upwith the idea for PCR while on asurfing trip in 1983. He won theNobel Prize in chemistry in 1993.How do scientists get an amount of DNA that is large enough to be studiedand manipulated? They copy the same segment of DNA over and over again.Polymerase chain reaction (PCR) is a technique that produces millions—oreven billions—of copies of a specific DNA sequence in just a few hours. Asthe name indicates, the DNA polymerase enzymes that help copy DNA playkey roles in this process.Kary Mullis, who invented PCR, is shown in figure 2.1. While working for aCalifornia biotechnology company in 1983, Mullis had an insight about how tocopy DNA segments. He adapted the process of DNA replication that occurs inevery living cell into a method for copying DNA in a test tube. Under the rightset of conditions, DNA polymerases copy DNA in a test tube just as they doinside cells. However, in cells several other enzymes are needed before thepolymerases can do their job. For example, before a cell can begin to copy itsDNA, enzymes called helicases unwind and separate DNA molecules. Insteadof using these enzymes, Mullis used heat to separate the DNA strands.Unfortunately, heat also broke down the E. coli polymerases that Mullisfirst used. Then came Mullis’s second stroke of genius: Why not use poly merases from a bacterium that lives in temperatures above 80 C (176 F)? Byusing this enzyme, Mullis was able to raise the temperature of the DNA toseparate the strands without destroying the DNA polymerases. Here again,just as with restriction enzymes that you read about in Section 1, a majoradvance came from applying an adaptation found in nature to biotechnology.Mullis introduced PCR to the world in 1985, and in 1993 he won the NobelPrize in chemistry for his revolutionary technique.Compare and Contrast How are replication and PCR similar? different? Explain.Chapter 9: Frontiers of Biotechnology259
FIGURE 2.2 Polymerase Chain Reaction (PCR)BiologyHMDScience.comPCR is a cyclical process that quickly makesmany copies of a DNA segment.GO ONLINEPolymerase Chain Reactionstarget sequence of DNA1Separating The container with allof the reactants is heated to morethan 90 C (194 F) for a few secondsto separate the strands of DNA.2DNA strandsBindingis cooledbhspe-03The0902container-002to about 55 C (131 F).The primersbind to the DNA strands.primer 1primer 2polymerase3nucleotidesCopying The container isheated to about 72 C (152 F),the temperature at which thepolymerases work best. Thepolymerases bind nucleotidesuntil the DNA segment hasbeen copied.PCR Amplifies DNA SamplesWith each PCR cycle, the number of copies of theDNA segment doubles. After 30 cycles, more than1 billion copies have been made.CRITICALVIEWINGHow many copies of DNA will exist after one more PCR cycle? After three more cycles?260 Unit 3: Genetics
Main IdeaPCR is a three-step process.PCR is a surprisingly simple process. It uses just four materials: the DNA to becopied, DNA polymerases, large amounts of each of the four DNA nucleotides(A, T, C, and G), and two primers. A primer is a short segment of DNA thatacts as the starting point for a new strand. If DNA polymerases build newDNA strands, why are primers needed for PCR? DNA polymerases can addnucleotides to strands that have already been started, but they cannot start thestrands. In PCR, two primers are used to start the copying of DNA close to thedesired segment. The two primers are like bookends for the DNA strand. Theylimit the length of the copied DNA to one small segment of the strand.PCR has three main steps, as shown in figure 2.2. All of the steps of thecycle take place in the same container but at different temperatures. The mainfunction of the first two PCR cycles is to produce the small segment of DNAthat is desired. By making a copy of the desired segment, many copies of thattiny piece of DNA can be made, rather than copying an entire chromosome.1R E A D I N G TO O L B oxVOCABULARYThe term primer comes froma Latin word that means “first.”In PCR, a primer is the startingpoint for the DNA copyingprocess.Separating The container with all of the reactants is heated to separatethe double-stranded DNA into single strands.2 Binding The container is cooled and the primers bind to their comple mentary DNA sequences. One primer binds to each DNA strand. Theprimers bind on opposite ends of the DNA segment being copied.3 Copying The container is heated again and the polymerases begin tobuild new strands of DNA. Added nucleotides bind to the original DNAstrands by complementary base pairing. The polymerases continueattaching nucleotides until the entire DNA segment has been copied.Each PCR cycle doubles the number of DNA copies. The original piece ofDNA becomes two copies. Those two copies become four copies. And the cycleis repeated over and over to quickly copy enough DNA for study. After only 30cycles of PCR, for example, the original DNA sequence is copied more than1 billion times. This doubling is why the process is called a chain reaction.CONNECT TOReplicationLook back at the process ofDNA replication in the chapterFrom DNA to Proteins tocompare PCR with replication.Infer Why is it necessary to keep changing the temperature in the PCR process?Self-check Online9.2HMDScience.comFormative AssessmentReviewingMain Ideas1. Briefly describe the function ofpolymerase chain reaction (PCR).6H2. Summarize the cycle involved in thePCR process.GO ONLINECritical thinking3. Synthesize Describe how heatingdouble-stranded DNA separates thestrands. Why does heating alsoinactivate DNA polymerases from9Cmany organisms?4. Analyze Explain two reasons whyprimers are important in PCR.CONNECT TOHuman Genetics5. Many human genetic diseasesare ca
restriction map KeY CONCept Biotechnology relies on cutting DNA at specific places. MAIN IDeAS Scientists use several techniques to manipulate DNA. Restriction enzymes cut DNA. Restriction maps show the lengths of DNA fragments. Connect to Your World 6H Many applications of genetics that are widely used today were unimaginable just 30 years ago.
The EDIT program provides two editors—EDIT, a line editor, and EDIT VS, a screen editor. The emphasis of this manual is on EDIT. The manual introduces you to the features and capabilities of EDIT, describes the many EDIT commands and their ranges, and provides information on creating and using EDIT files. For those users who wish to use EDIT .
84. Verne, Jules.- Journey to the Centre of the Earth . Edit. Oxford. 85. Vicary, Tim.- The Elephant Man . Edit. Oxford Bookworms 1 86. Vicary, Tim.- Justice . Edit. Oxford Bookworms 3 87. Vicary, Tim.- Chemical Secret. Edit. Oxford Bookworms 3. 88. Vicary, Tim.- Skyjack!. Edit. Oxford Bookworms 3. 89. Viney, Peter.- Strawberry and the Sensations. Edit. Oxford. 90.
The PS TEXT EDIT and PS TEXT FORMAT User's Guide is a task-oriented, step-by-step guide to using TEDIT and TFORM. The PS TEXT EDIT Reference Card gives you a handy summary of TEDIT functions and commands. The EDIT/VS to TEDIT Reference Card compares TEDIT functions to those of EDIT. The PS TEXT EDIT Independent Study Program (ISP) is a self-paced
Overwatch: Learning Patterns in Code Edit Sequences 139:3 (a) Edit suggestions based on spatial context (b) Edit suggestion using spatial and temporal contexts Fig. 1. Edits suggested by Visual Studio when the developer adds a property to a class input, Overwatch's problem is to find recurrent edit sequences and generalize them into Edit
Houghton Mifflin Harcourt Publishing Company Image Credits (t to b): Lubor Zelinka/Shutterstock; Zauberschmeterling/iStock/Getty Images; Paul Bradbury .
Feb 23, 2018 · The Hypotenuse-Leg (HL) Triangle Congruence Theorem is a special case that allows you to show that two right triangles are congruent. Hypotenuse-Leg (HL) Triangle Congruence Theorem If the hypotenuse and a leg of a right triangle are congruent to the hypotenuse and a
Entering a Retroactive Pay Historical Edit 12. Click the Save button to save this historical edit. After clicking the Save button, the timecard will appear. An additional row will have been added by CalTime on the date with the historical edit. In this example that is Friday 8/29. The line that is the historical edit will have a gray background .
Feb 23, 2018 · 7.3 Triangle Inequalities Essential Question:How can you use inequalities to describe the relationships among side lengths and angle measures in a triangle? DO NOT EDIT--Changes must be made through "File info" CorrectionKey NL-A;CA-A GE_MNLESE385795_U2M07L3.indd 341 02/04/14 1:36 AM Common Core Math Standards
