HESI EXIT EXAM STUDY QUESTIONS AND ANSWERS

CHAPTER 19 SOLUTIONS MANUAL
QUESTIONS AND ANSWERS


2.byWhatbyfeaturebyisbycommonlybyseenbyinbythebysequencesbyrecognizedbybybytypebyIIbyrestriction
byenzymes?by-byanswer--Solution:

Thebyrecognitionbysequencesbyarebypalindromic,byandby4−8bybasebypairsbylong.

3.byWhatbynormalbyrolebydobyrestrictionbyenzymesbyplaybyinbybacteria?
byHowbydobybacteriabyprotectbytheirbyownbyDNAbyfrombythebyactionbyofbyrestrictionbyenzymes?by-

byanswer--Solution:

RestrictionbyenzymesbycutbyforeignbyDNA,bysuchbyasbyviralbyDNA,byintobyfragments.byBacteriabypr
otectbytheirbyownbyDNAbybybymodifyingbybases,byusuallybybybymethylation,byatbythebyrecognitionby
sites.

4.byExplainbyhowbygelbyelectrophoresisbyisbyusedbytobyseparatebyDNAbyfragmentsbyofbydifferentbyle
ngths.by-byanswer--Solution:
GelbyelectrophoresisbyusesbyanbyelectricbyfieldbytobydrivebyDNAbymoleculesbythroughbyabygelbythatb
yactsbyasbyabymolecularbysieve.byThebygelbyisbyanbyaqueousbymatrixbyofbyagarosebyorbypolyacrylam

ide.byDNAbymoleculesbyarebyloadedbyintobyabyslotbyorbywellbyatbyonebyendbyofbythebygel.byWhenbyanby
electricbyfieldbyisbyapplied,bythebynegativelybychargedbyDNAbymoleculesbymigratebytowardbythebyp
ositivebyelectrode.byShorterbyDNAbymoleculesbyarebylessbyhinderedbybybythebyagarosebyorbypolya
crylamidebymatrixbyandbymigratebyfasterbythanbylongerbyDNAbymolecules,bywhichbymustbywindbyth
eirbywaybyaroundbyobstaclesbyandbythroughbythebyporesbyinbythebygelbymatrix.

5.byAfterbyDNAbyfragmentsbyhavebybeenbyseparatedbybybygelbyelectrophoresis,byhowbycanbytheyby
bebyvisualized?by-byanswer--Solution:
DNAbymoleculesbycanbybebyvisualizedbybybystainingbywithbyabyfluorescentbydye,bysuchbyasbyethidiu
mbybromide,bythatbyintercalatesbybetweenbythebystackedbybasesbyofbythebyDNAbydoublebyhelix,bya
ndbythebydye-
DNAbycomplexbyfluorescesbywhenbyirradiatedbywithbyanbyultravioletbylightbysource.byAlternatively,
bytheybycanbybebyvisualizedbybybyattachingbyradioactivebyorbychemicalbylabelsbytobythebyDNAbybefo

rebyitbyisbyplacedbyinbythebygel.

6.byWhatbyisbythebypurposebyofbySouthernbyblotting?byHowbyisbyitbycarriedbyout?by-byanswer--
Solution:
SouthernbyblottingbyisbyusedbytobydetectbyandbyvisualizebyspecificbyDNAbyfragmentsbythatbyhaveby
abysequencebycomplementarybytobyabylabeledbyDNAbyprobe.byDNAbyisbyfirstbycleavedbyintobyfragm
entsbywithbyrestrictionbyendonucleases.byThebyfragmentsbyarebyseparatedbybybysizebyviabygelbyele
ctrophoresis.byThesebyfragmentsbyarebythenbydenaturedbyandbytransferredbybybyblottingbyontobyth
ebysurfacebyofbyabymembranebyfilter.byThebymembranebyfilterbynowbyhasbysingle-
strandedbyDNAbyfragmentsbyboundbytobyitsbysurface,byseparatedbybybysizebyasbyinbythebygel.byTheb
yfilterbyisbythenbyincubatedbywithbyabysolutionbycontainingbyabydenatured,bylabeledbyprobebyDNA.by

ThebyprobebyDNAbyhybridizesbytobyitsbycomplementarybyDNAbyonbythebyfilter.byAfterbywashingbyaw
aybyexcessbyunboundbyprobes,bythebylabeledbyprobebyhybridizedbytobythebyDNAbyonbythebyfilterbyca
nbybebydetectedbyusingbythebyappropriatebymethodsbytobyvisualizebythebylabel.byForbyradioactivelyb
ylabeledbyprobes,bythebyboundbyprobebyisbydetectedbybybyexposurebytobyX-

, raybyfilm.byOtherbyprobebylabelingbymethodsbydetectbyboundbyprobebyusingbyenzymaticbyreaction
sbythatbygeneratebyluminescencebyorbycolor.

7.byGivebythreebyimportantbycharacteristicsbyofbycloningbyvectors.by-byanswer--Solution:
Cloningbyvectorsbyshouldbyhave:
(1)byAnbyoriginbyofbyDNAbyreplicationbysobytheybycanbybebymaintainedbyinbyabycell
(2)byAbygene,bysuchbyasbyantibioticbyresistance,bytobyselectbyforbycellsbythatbycarrybythebyvector
(3)byAbyuniquebyrestrictionbysitebyorbyseriesbyofbysitesbytobywherebyabyforeignbyDNAbymoleculebymay
bebyinserted

9.byBrieflybyexplainbyhowbyanbyantibiotic-
resistancebygenebyandbythebylacZbygenebycanbybebyusedbytobydeterminebywhichbycellsbycontainbyab
yparticularbyplasmid.by-byanswer--Solution:

Manybyplasmidsbydesignedbyasbycloningbyvectorsbycarrybyabygenebyforbyantibioticbyresistancebyan
dbythebylacZbygene.byThebylacZbygenebyonbythebyplasmidbyhasbybeenbyengineeredbytobycontainbymu
ltiplebyuniquebyrestrictionbysites.byForeignbyDNAsbyarebyinsertedbyintobyonebyofbythebyuniquebyrestri
ctionbysitesbyinbythebylacZbygenebyofbyplasmidsbyandbythebyplasmidsbyarebytransformedbyintobyE.byc
olibycellsbylackingbyabyfunctionalbylacZbygene.byTransformedbycellsbyarebyplatedbyonbyabymediumbyc
ontainingbythebyappropriatebyantibioticbytobyselectbyforbycellsbythatbycarrybythebyplasmid.byThebyme
diumbyalsobycontainsbyanbyinducerbyforbythebylacbyoperon,bysobythebycellsbyexpressbythebylacZbygen
e,byandbyX-gal,byabysubstratebyforbybeta-
galactosidasebythatbywillbyturnbybluebywhenbycleavedbybybyβ-
galactosidase.byThebycoloniesbythatbycarrybyplasmidbywithoutbyforeignbyDNAbyinsertsbywillbyhaveby
intactbylacZbygenes,bymakebyfunctionalbyβ-galactosidase,bycleavebyX-
gal,byandbyturnbyblue.byColoniesbythatbycarrybyplasmidbywithbyforeignbyDNAbyinsertsbywillbynotbyma
kebyfunctionalbyβ-
galactosidasebybecausebythebylacZbygenebyisbydisruptedbybybythebyforeignbyDNAbyinsert.byTheyby
willbyremainbywhite.byThus,bycellsbycarryingbyplasmidsbywithbyinsertsbywillbyformbywhitebycolonies.by
Thisbyisbyknownbyasbyblue/whitebyselection.

10.byBrieflybyexplainbyhowbythebypolymerasebychainbyreactionbyisbyusedbytobyamplifybyabyspecificby
DNAbysequence.by-byanswer--First,bythebydouble-
strandedbytemplatebyDNAbyisbydenaturedbybybyhighbytemperature.byThen,byprimersbycorrespondi
ngbytobythebyendsbyofbythebyDNAbysequencebytobybebyamplifiedbyarebyannealedbytobythebysingle-
strandedbyDNAbytemplatebystrands.byThesebyprimersbyarebyextendedbybybyabythermostablebyDN
AbypolymerasebysobythatbythebytargetbyDNAbysequencebyisbyduplicated.byThesebystepsbyarebyrepe
atedby30bytimesbyorbymore.byEachbycyclebyofbydenaturation,byprimerbyannealing,byandbyextensionb
yresultsbyinbydoublingbythebynumberbyofbycopiesbyofbythebytargetbysequencebybetweenbythebyprimer

s.

12.byHowbydoesbyabygenomicbylibrarybydifferbyfrombyabycDNAbylibrary?by-byanswer--Solution:
AbygenomicbylibrarybyisbygeneratedbybybycloningbyfragmentsbyofbychromosomalbyDNAbyintobyabyclo
ningbyvector.byChromosomalbyDNAbyisbyrandomlybyfragmentedbybybyshearingbyorbybybypartialbydi
gestionbywithbyabyrestrictionbyenzyme.byAbycDNAbylibrarybyisbymadebyfrombymRNAbysequences.by
CellularbymRNAsbyarebyisolatedbyandbythenbyreversebytranscriptasebyisbyusedbytobycopybythebymR
NAbysequencesbytobycDNA,bywhichbyarebyclonedbyintobyplasmidbyorbyphagebyvectors.byThereforeby
abycDNAbylibrarybyonlybyrepresentsbythebygenesbyexpressedbyinbythebytissuesbyofbyoriginbyforbytheby
RNA.

13.byHowbyarebyprobesbyusedbytobyscreenbyDNAbylibraries?by-byanswer--Solution:
ThebyDNAbylibrarybymustbyfirstbybebyplatedbyout,byeitherbyasbycoloniesbyforbyplasmidbylibrariesbyorby
phagebyplaquesbyonbyabybacterialbylawnbyforbyphagebylibraries.byThebycoloniesbyorbyplaquesbyareby