TPO36阅读文本和题目正式版doc资料.docx

TPO36阅读文本和题目正式版doc资料.docx

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TPO36阅读文本和题目正式版doc资料

TPO36阅读文本和题目正式版

TPO36-1

TheFirstEye

Puttingadateonthefirstappearanceofeyesdependsonwhatonemeansbyeye.Ifthetermreferstoamulticellularorgan,evenifithasjustafewcells,thenbydefinition,eyescouldnotformbeforethereweremulticellularanimals.Butmanyprotists（animal-like,plantlike,orfungus-likeunicellularorganismsthatrequireawater-basedenvironment）candetectlightbyusingaggregationsofpigmentmolecules,andtheyusethisinformationtomodifytheirmetabolicactivityormotility（theabilitytomovespontaneouslyandindependently）.Oneofthefamiliarlivingexamples,probablyknowntoanyonewhohastakenabiologyclass,istheaquaticprotozoanEuglena,whichhasaneyespotnearitsmotilefIagellum（hairlikestructure）.Somelivingprotistsareveryliketheirancestralformsembeddedinancientsedimentaryrocks,andthissimilaritysuggeststhattheabilitytodetectlightandmodifybehaviorinresponsetolighthasbeenaroundforaverylongtime.Animalsarosefromoneofsuchunicellularcreatures,perhapsfromonealreadyspecializedforaprimitivekindofvision.

Aneyeisacollectionofcellsthatarespecializedforlightdetectionthroughthepresenceofphotosensitivepigmentaswellasameansofrestrictingthedirectionofincominglightthatwillstrikethephotosensitivecells.Thisdefinitionsaysnothingaboutimageformation,lenses,eyemovements,oranyoftheotherfeaturesweassociatewithourowneyes,butitdoesrecognizethesimplestformoffunctionalandanatomicalspecialisationnamely,detectionoflight.Everythingelsecanbebuiltupfromthissimplebeginning,andsomeanimalsappeartohavehadeyesalmostfromthebeginningoftheanimalkingdom.

Animalswerescarce600millionyearsagointhegeologicaleracalledthePrecambrian.Thereareveryfewfossilremainsfromthattime（thoughmorekeepturningup）,andmostevidenceofthepresenceofanimalsisindirect,suchassmalltunnelsinrockthatcouldbeancientwormburrowings.Butjust50millionyearsorsolater,fossilizedbitsandpiecesofanimalsabound,suggestingthatagreatburstofevolutionarycreativityoccurredinthe50-million-yearinterval.Thissurgeofnewlife,markedbyanabundanceofanimals,iscalledtheCambrianexplosion.

Thefirstdirectevidencefortheearlyoriginofeyescomesfromfossilsthatareabout530millionyearsold,atimeshortlyaftertheCambrianexplosion;theywerefoundonamountainsideinBritishColumbiainadepositknownastheBurgessShale.TheBurgessShalefossilsareextraordinarilyimportantbecauseamongthemareremainsofsoft-bodiedcreatures,manyofthemlackingshellsandotherhardpartsthatfossilizeeasily.Consequently,theirpreservationislittleshortofmiraculous（asarethedelicatemethodsusedtoreconstructthree-dimensionalstructurefromtheseflattenedfossils）,andtheyareoneofthefewknownrepositoriesofearlysoft-bodiedanimals.

NotalloftheBurgessanimalshadeyes.However,somedid.（Grossfeatureslocation,size,andhemisphericshapeareresponsibleforthedesignationofsomestructuresaseyes）.ThereconstructedeyesoftheseBurgessanimalslooksuperficiallylikeeyesofsomelivingcrustaceans,particularlythoseofshrimpandcrabswhoseeyesaremountedonstalksthatimprovetherangeofvisionbyraisingtheeyesabovethesurfaceofthehead.TheeyesofsomeBurgessorganismssatonstalks;thoseofotherswereonorapartofthebodysurface.Oneanimal,Opabinia,hadfiveeyes:

twolateralpairsandasinglemedialeye;atleastoneofthelateralpairshadstalksthatcouldhavebeenmovable.Andsometrilobite-likeanimalsintheBurgessShalehadfacetedeyesmuchlikethoseoflaterfossiltrilobites.

AlthoughthepresenceofeyesonsomeoftheBurgessanimalsindicatesthateyeshavebeenaroundforaverylongtime,itisunlikelythatthesewerethefirsteyes;theyseemmuchtoolargeand（potentially）welldevelopedtobebrandnewinventions.ThebestwecandoisputtheoriginofeyessomewherebetweenthebeginningoftheCambrianexplosion,about600millionyearsago,andthedeathoftheBurgessanimals,some530millionyearsago.

Paragraph1:

Puttingadateonthefirstappearanceofeyesdependsonwhatonemeansbyeye.Ifthetermreferstoamulticellularorgan,evenifithasjustafewcells,thenbydefinition,eyescouldnotformbeforethereweremulticellularanimals.Butmanyprotists（animal-like,plantlike,orfungus-likeunicellularorganismsthatrequireawater-basedenvironment）candetectlightbyusingaggregationsofpigmentmolecules,andtheyusethisinformationtomodifytheirmetabolicactivityormotility（theabilitytomovespontaneouslyandindependently）.Oneofthefamiliarlivingexamples,probablyknowntoanyonewhohastakenabiologyclass,istheaquaticprotozoanEuglena,whichhasaneyespotnearitsmotilefIagellum（hairlikestructure）.Somelivingprotistsareveryliketheirancestralformsembeddedinancientsedimentaryrocks,andthissimilaritysuggeststhattheabilitytodetectlightandmodifybehaviorinresponsetolighthasbeenaroundforaverylongtime.Animalsarosefromoneofsuchunicellularcreatures,perhapsfromonealreadyspecializedforaprimitivekindofvision.

1.Theword“aggregations”inthepassageisclosestinmeaningto

☐Parts.

☐Reactions.

☐Groups.

☐Types.

2.Paragraph1supportsallofthefollowingstatementsaboutprotistsEXCEPT:

☐Somearemulticellular.

☐Someareabletomove.

☐Somehavepigmentmolecules.

☐Theyliveinenvironmentsthatcontainmoisture.

3.Accordingtoparagraph1,whathavescientistsconcludedfromthefactthatsomelivingprotistsareveryliketheirancestralforms

☐Theeyedidnotevolveuntilmulticellularorganismsarose.

☐Theabilitytodetectlightandchangebehaviorinresponsetolighthasexistedforalongtime.

☐Theancestralformsoftheselivingprotistslikelyhadaneyespotnearthemotileflagellum.

☐Theancestralformsoftheselivingprotistsdependedprimarilyonlightasthemechanismformodifyingtheirmetabolicactivityormotility.

Paragraph2:

Aneyeisacollectionofcellsthatarespecializedforlightdetectionthroughthepresenceofphotosensitivepigmentaswellasameansofrestrictingthedirectionofincominglightthatwillstrikethephotosensitivecells.Thisdefinitionsaysnothingaboutimageformation,lenses,eyemovements,oranyoftheotherfeaturesweassociatewithourowneyes,butitdoesrecognizethesimplestformoffunctionalandanatomicalspecialisationnamely,detectionoflight.Everythingelsecanbebuiltupfromthissimplebeginning,andsomeanimalsappeartohavehadeyesalmostfromthebeginningoftheanimalkingdom.

4.Paragraph2implieswhichofthefollowingabouttheearlyeyes

☐Theywereabletodetectsimplemovementsalmostfromthebeginningoftheirevolution.

☐Theywerenotassensitivetolightasoncethought.

☐Theycouldnotformimages.

☐Theircellshadmorephotosensitivepigmentthandohumaneyes

Paragraph3:

Animalswerescarce600millionyearsagointhegeologicaleracalledthePrecambrian.Thereareveryfewfossilremainsfromthattime（thoughmorekeepturningup）,andmostevidenceofthepresenceofanimalsisindirect,suchassmalltunnelsinrockthatcouldbeancientwormburrowings.Butjust50millionyearsorsolater,fossilizedbitsandpiecesofanimalsabound,suggestingthatagreatburstofevolutionarycreativityoccurredinthe50-million-yearinterval.Thissurgeofnewlife,markedbyanabundanceofanimals,iscalledtheCambrianexplosion.

5.Whichofthesentencesbelowbestexpressestheessentialinformationinthehighlightedsentenceinthepassage.Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.

☐TherearefewfossilsfromthePrecambrian,thoughmorekeepturningup.

☐MostevidenceofanimalsinthefossilrecordisindirectandlittleofitisfromthePrecambrian.

☐TunnelsinPrecambrianrocksthatmayhavebeenmadebywormsprovideindirectevidenceoftheseanimalsexistingatthattime.

☐ThereareveryfewfossilsofanimalsfromthePrecambrianandmostevidenceofanimallifefromthatperiodisindirect.

6.Accordingtoparagraph3,theCambrianperiodwascharacterizedby

☐Agreatabundanceofanimals

☐Aslowrateofanimalextinction

☐Therapidfossilizationofanimals

☐Anincreaseinthelifespanofsomeanimals

Paragraph4:

Thefirstdirectevidencefortheearlyoriginofeyescomesfromfossilsthatareabout530millionyearsold,atimeshortlyaftertheCambrianexplosion;theywerefoundonamountainsideinBritishColumbiainadepositknownastheBurgessShale.TheBurgessShalefossilsareextraordinarilyimportantbecauseamongthemareremainsofsoft-bodiedcreatures,manyofthemlackingshellsandotherhardpartsthatfossilizeeasily.Consequently,theirpreservationislittleshortofmiraculous（asarethedelicatemethodsusedtoreconstructthree-dimensionalstructurefromtheseflattenedfossils）,andtheyareoneofthefewknownrepositoriesofearlysoft-bodiedanimals.

7.Thephraselittleshortofmiraculousisclosestinmeaning

☐Toveryhighlyvalued

☐Amazingbecausealmostimpossible

☐Causingcontroversy

☐Almostbutnotquitecomplete

8.Accordingtoparagraph4,allofthefollowingaretrueoftheBurgessShaleEXCEPT:

☐Itsfossilswereinaflattenedconditionwhendiscovered.

☐Itsfossilsprovidedirectevidenceabouttheoriginofeyes.

☐ItcontainsfossilsofbothPrecambrianandCambriananimals.

☐Itcontainsfossilizedremainsofsoft-bodiedorganism