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1、Furtherdevelopment1.definitionofcloningCloning,creatingacopyoflivingmatter,suchasacellororganism.Thecopiesproducedthroughcloninghaveidenticalgeneticmakeupandareknownasclones.Manyorganismsinnaturereproducebycloning.Scientistsusecloningtechniquesinthelaboratorytocreate
2、copiesofcellsororganismswithvaluabletraits.Theirworkaimstofindpracticalapplicationsforcloningthatwillproduceadvancesinmedicine,biologicalresearch,andindustry.2.HOWSCIENTISTSCLONECELLSA.BlastomereSeparationInblastomereseparation,scientistsfertilizeaneggcellwithaspermc
3、ellinalaboratorydish.Theresultingembryoisallowedtodivideuntilitformsamassofaboutfourcells.Scientistsremovetheoutercoatingoftheembryoandplaceitinaspecialsolutionthatcausestheindividualcellsoftheembryo,knownasblastomeres,toseparate.Scientiststhenputeachblastomereincult
4、ure,whereitformsanembryocontainingthesamegeneticmakeupastheoriginalembryo.Eachnewembryocanthenbeimplantedintotheuterusofasurrogatemothertodevelopduringanormalpregnancy.B.BlastocystDivisionInblastocystdivision,scientistsallowafertilizedeggtodivideuntilitformsamassofab
5、out32to150cells,knownasablastocyst.Scientiststhensplittheblastocystintwoandimplantthetwohalvesintotheuterusofasurrogatemother.Thetwohalvesdevelopasidenticaltwins.C.SomaticCellNuclearTransferWhileblastomereseparationandblastocystdivisionproduceanimalscontainingthegene
6、ticmaterialfrombothamotherandfather,somaticcellnucleartransferproducesananimalcarryingthegeneticmaterialofonlyoneparent.Inthistechnique,scientiststransferthegeneticmaterialfromadonor’ssomaticcell(anybodycellotherthananeggorspermcell)toanenucleatedeggcell—thatis,anegg
7、cellwithitsnucleus,andthusitsgeneticmaterial,removed.Theresultingclonedcellcontainsthegeneticmaterialofthedonor’ssomaticcell.GeneticEngineeringGeneticengineeringenablesscientiststoproduceclonesofcellsororganismsthatcontainthesamegenes.1.Scientistsuserestrictionenzyme
8、stoisolateasegmentofdeoxyribonucleicacid(DNA)thatcontainsageneofinterest—forexample,thegeneregulatinginsulinproduction.2.Aplasmidre
