遗传学周测题目含参考答案.docx

遗传学周测题目含参考答案.docx

《遗传学周测题目含参考答案.docx》由会员分享，可在线阅读，更多相关《遗传学周测题目含参考答案.docx（20页珍藏版）》请在冰豆网上搜索。

遗传学周测题目含参考答案

注意：

开始时间2014-10-18的16:

00，

结束时间2014-10-19的24:

00

周测一

1.WhichofthefollowingdiseasesresultsfromfaultyDNArepair?

（6.0分）

A.neurofibromatosistype1

B.xerodermapigmentosum

C.retinoblastoma

D.osteogenesisimperfecta

E.hemophiliaA

2.在基因组的间隔序列和内含子等非编码区内，广泛存在着与小卫星DNA相似的一类小重复单位，重复序列为（），称为微卫星DNA或STR，如（A）n/（T）n、（CA）n/（TG）n、（CT）n、（AG）n等。

（6.0分）

A.2~6kb

B.15~100kb

C.1~5kb

D.10~60kb

E.170~300kb

3.IfthesequenceofnucleotidesinageneisT-T-A-C-G-A-G,thesequenceofnucleotidesinmRNAsynthesizedbyitis（6.0分）

A.A-A-U-G-C-U-C

B.T-T-A-C-G-A-G

C.A-A-T-G-C-T-C

D.A-A-T-G-C-T-G

E.T-T-U-G-C-U-G

4.Geneissplit,alternatewiththeexonsandtheintrons.（6.0分）

A.ThenumbersofexonsandintronsinageneareN+1andNrespectively.Exonsarevariableandintronsareconserved.

B.Intronsarethenon-encodingsequencesandthecorrespondingRNAsequencewillberemovedfrommRNA.TheirmutationsdonotinfluencethesplicingofRNAandaffecttheproductionofmRNA

C.ExonsaretheencodingsequencescorrespondingtothesequenceofmRNAandtheirmutationswillinfluencetheformationofproteins.

D.Splicesiteislocatedinthejunctionregionofintronandexon,whereintronalwaysstartsatATandendsatCG.

5.Anucleotidesubstitutioncannotcausewhichofthefollowing?

（6.0分）

A.nonsense

B.Frameshift

C.missense

D.samesense

6.Whichofthefollowingstatementaboutpolymorphysimisnotcorrect?

（6.0分）

A.Singlenucleotidepolymorphisms（SNPs）occuraboutonceevery500-1000bpinthehumangenome.

B.MinisatellitesandMicrosatellitesarenottherepeatDNAsequenceinthehumangenomeandbothcannotbeusedaspolymorphysimmarker.

C.RFLPisthe1stgenerationofmarkersusedinhumans

D.RestrictionRFLPMappingcanbecombinedwithSouthernBlotAnalysistodetectthedifferencesinDNAsamples.

7.Thehereditarycharacteristicsaretransmittedasunitswasdiscoveredby（6.0分）

A.Fleming

B.Morgan

C.Mendel

D.Sutton

8.Cross-overisafamiliartermto（6.0分）

A.Hybridiztion

B.Diffusionfromonesideofamembranetotheother

C.Migrationacrossdifficultgeographicalbarriers

D.Interchangeofsectionsofchromatids

E.Pollinationinvolvingseparateflowers,maleandfemale

9.ThehypotheticalSouthernblotshowbelowillustratesaDNA“fingerprinting”analysistoexaminepaternity,wherematernal（M）,child（C）,andpaternal（F）DNAsampleshavebeenrestricted,blotted,andhybridizedsimultaneouslytotheprobeD1S220andD7S123.（DNAmarkeristhestandardladder）.Thedistributionsofrestrictionfragmentallelessuggest（6.0分）

A.Correctmaternityandpaternity

B.Falsematernity（i.e.babyswitchedinthenursery）

C.Falsepaternity

D.Thechildisadopted

E.Noneoftheabove

10.Thepresenceofgenesinthesamechromosomeisanexampleof（6.0分）

A.Segregations

B.Coordination

C.Freeassortment

D.Linkage

E.Fusion

11.外显子与内含子接头序列为_______。

（6.0分）

A.5’GT-AT3’

B.5’GT-AG3’

C.5’GG-AT3’

D.5’AG-GT3’

12.发病率最高的遗传病是（）（7.0分）

A.单基因病

B.染色体病

C.多基因病

D.体细胞遗传病

13.目前已知人类最大的基因，大约由（）和相应的内含子组成，cDNA全长为11000bp，编码分子量为427000的蛋白质，从dystrophin转录形成一条完整的mRNA分子需要16h。

（7.0分）

A.60个外显子

B.40个外显子

C.70个外显子

D.80个外显子

E.79个外显子

14.Accordingtopresentthinking,whichofthefollowingstatementsaboutcodonsisincorrect?

（7.0分）

A.Thereisevidencetosupportthetheorythatthecellreadsthecodonsinsequencefromagivenpoint

B.Thecodonarenonoverlapping

C.Twoormorecodonsoftencodeforthesameaminoacid

D.Thecodonconsisitsoffournucleotides

E.Nucleotidesequence（genes）areprobablyseparatedbyspacersthatarenonsensecodons

15.Meiosis1isknownasthe（6.0分）

A.reductiondivision

B.diploiddivision

C.sexualdivision

D.equilibrationdivision

16.Geneticdiseasescausedbywhichofthefollowingtypesofmutationwouldbemostamenabletoreplacementtherapywiththerelevantgeneproduct（providedyoucouldgetitwhereitneededtogo）?

（7.0分）

A.haploinsufficient

B.geneduplication

C.dominatnegative

D.anyoftheabove

周测二

1.

Thusfar,twogeneshavebeenfoundthatcancauseautosomaldominantbreastcancer（oneonchromosome13andoneonchromosome17）.Thisisbestdescribedasanexampleof:

（4.0分）

A.Allelicheterogeneity

B.Linkage

C.Linkagedisequilibrium

D.Locusheterogeneity

2.Contrastinggenesatthesamelocusarecalled（4.0分）

A.Difactors

B.Alleles

C.Allies

D.Homologus

E.Associates

3.某人的父亲为Huntington舞蹈病患者，他现已30岁还未发病，如果30岁时此病的外显率为30%，则他将来发病的可能性为（）。

（4.0分）

A.35%

B.15%

C.0%

D.100%

E.30%

4.Yourpatientisa5-year-oldgirlwhoappearstohaveDuchennemusculardystrophy.Whatisthemostlikelygeneticexplanationforthisdiseaseinagirl?

（4.0分）

A.Shehasadominantnegativemutation.

B.ShehasskewedXinactivation.

C.ShehastwoindependentDMDmutations.

D.Shehasa46,XYkaryotypewithsexreversal.

E.Thisdiagnosisisimpossible.

5.父亲为A血型，母亲为B血型，生育了1个B血型的孩子，如再生育，孩子可能的血型为（）。

（4.0分）

A.A、B和AB

B.B和AB

C.A和B

D.A和AB

E.A、B、AB和O

6.Manybiochemicaldefects,whichareinheritedinasingle-geneMendelianfashion,havemultipleeffectsupontheindividualaffected.Thisphenomenonisknownas:

（4.0分）

A.pleiotropy

B.phenocopying

C.incompletepenetrance

D.codominance

7.Huntington舞蹈病患者重复扩增的三联体是（）。

（4.0分）

A.GCG

B.CAG

C.CTG

D.GAA

E.CGG

8.MuttandJeffaretwobrotherswhowerebornwithcongenitaldeafness.Theirparentshadnormalhearing.MuttmarriedMabel.Mabelwasalsocongenitallydeafandherparentshadnormalhearing.MuttandMabelhad10children（5boysand5girls）allofwhomwereborncongenitallydeaf.JeffmarriedJane.JaneisnotrelatedtoMabel.Janewascongenitallydeafalthoughherparentshadnormalhearing.Jane’ssister,Myrna,wasalsocongenitallydeaf.JeffandJanehad10children（5boysand5girls）noneofwhomwerecongenitallydeaf.Theprobableexplanationoftheabovepedigreeisthat:

（4.0分）

A.thereisasinglegeneticlocuswithatleast2differentabnormalrecessivealleles（aandb）whichwillresultincongenitaldeafnesswhenhomozygousaseitherrecessiveaa,aborbb.

B.thereareatleast2differentgeneticlociwhichhaveabnormalrecessivealleleswhichwillresultincongenitaldeafnesswheneitherlocusishomozygousforitsabnormalallele.

C.thereareatleast2differentgeneticlociwhichhaveabnormalrecessivealleleswhichwillresultincongenitaldeafnesswhenbothlociarehomozygousfortheirabnormalalleles.

D.Jeff’scongenitaldeafnessresultedfromaspontaneousmutationandhencecannotbepassedon.

9.一个男孩是甲型血友病（XR）的患者，其父母和祖父母均正常，其亲属中不可能患此病的人是（）（4.0分）

A.姑姑

B.姨表兄弟

C.外祖父或舅父

D.同胞兄弟

10.Matchthedescriptionsbelowwiththeappropriateterm.Agrandsonandpaternalgrandfatherhaveectrodactyly（aoutosomaldominantdisorderwithabsentmiddlefingers）,butthefatherhasnormalhands（4.0分）

A.Variableexpressivity

B.Germinalmosaicism

C.NonrandomXiinactivation

D.Geneticheterogeneity

E.Incompletepenetrance

11.Matchthecharacteristicstothemodeofinheritance.Elevatedpaternalageischaracteristic（4.0分）

A.Autosomaldominant

B.Chromosomal

C.X-linkedrecessive

D.Autosomalrecessive

E.Polygenic

12.Ayoungcouplebothaffectedwithclassicalachondroplasiacometoyouforgeneticcounseling.Thereisnootherfamilyhistoryofachondroplasia.Youshouldinformthemthatiftheyhaveatulltermliveborn,theprobabi1itythatthenewbornwi11nothaveachondroplasifabout:

（4.0分）

A.33%

B.25%

C.<1%

D.50%

13.多指症为常染色体显性遗传病，如果其外显率为60%，两个杂合型患者婚后所生子女表型正常的概率为（）。

（4.0分）

A.20%

B.50%

C.30%

D.55%

E.15%

14.Onecharacteristicofamutationisthatitis（4.0分）

A.Geneticallytransmittedtofuturegenerations

B.Almostanimprovement

C.Alwaysadominantcharacteristic

D.Preventedbyusingcolchicine

15.Matchthecharacteristicstothemodeofinheritance.Whenmale-to-maletransmissionisobserved,thismodeisunlikely（4.0分）

A.Autosomalrecessive

B.Autosomaldominant

C.X-linkedrecessive

D.Chromosomal

E.Polygenic

16.A34-year-oldwomanpresentstotheemergencyroomwithburning,stabbing,epigastricabdominalpain.Shereportsnauseaandvomitingoverthepast24hoursandstatesthatshethinksthatshemaybepregnant.Urinalysisispositiveforketones,WBCs,RBCs,andbacteria.Pregnancytestispositive.AnabdominalCTrevealsthrombosesinthesplenic,superiormesenteric,andleftrenalandportalveins.FurthertestingrevealsafactorVLeidenmutationinoneallele.Thereisnofamilyhistoryofthrombosisdisordersinherfamilyorherhusband’sfamily.Furtheranalysisrevealsamutationinthemother’sfactorVLeidengene;thefatherdoesnothavethemutation.Thepatientisconcernedaboutherpregnancyinlightofthesefindings.WhatistheprobabilityherchildwillbeaffectedbyfactorVLeidenthrombophila?

（4.0分）

A.Virtually0%

B.75%

C.50%

D.25%

E.100%

17.Matchthedescriptionsbelowwiththeappropriateterm.A90-year-oldmanwithautosomaldominantneurofibromatosishasasonandgrandsonwhodiedintheirtwentiesfromneuraltumors（4.0分）

A.Geneticheterogeneity

B.NonrandomXiinactivation

C.Germinalmosaicism

D.Variableexpressivity

E.Incompletepenetrance

18.Phenylketonuria（PKU）isanautosomalrecessivediseasethatcausesseverementalretardationifitisundetected.TwonormalparentsaretoldbytheirstateneonatalscreeningprogramthattheirthirdchildhasPKU.Assumetheinitialscreeningisaccurateandanswerthequestionsbelow.WhatistheriskfortheirnextchildtohavePKU?

（4.0分）

A.100%

B.50%

C.67%

D.25%