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Molecular Biology
Midterm Exam 1
1. In an attempt to explain the laws of human heredity the Greek physician Alcmaeon suggested
that genetic material was transmitted from different parts of the human body to the sperm and
eggs which would then join to make an embryo. Which of the following theories most accurately
describes Alcmaeon’s views of heredity?
A. Theory of Pangenesis
B. Chromosomal Theory of Inheritance
C. Germ Cell Theory
D. The Blending Theory
2. Nearly 23 centuries after Alcmaeon’s attempts to explain human heredity, August Weismann
surgically removed the tails of mice (which were then mated) for 23 generations. Despite
removing the tails prior to mating the progeny all had tails. Which of the following theories was
put forth by Weismann to explain his findings and replace Alcmaeon’s ideas?
A. Theory of Pangenesis
B. Germ Plasm Theory
C. Chromosomal Theory of Inheritance
D. Law of Independent Segregation
3.GregorMendelcrossedpurebreedingpeaplantsandanalyzedtheinheritancepatterns
ofseveraldifferenttraitssuchasplantheight,seedcolorandpodtexture.HisLawof
IndependentSegregationappliestowhichofthefollowing?
A.Theinheritancepatternoftwogenesthatlieclosetogetheronasinglechromosome.
B.Theinheritancepatternoftwoallelesofthesamegene.
C.Theinheritancepatternoftwogenesthatresideondifferentchromosomes.
D.TheinheritancepatternofgenesthatlieontheXchromosome.
4.Mendel’sLawofIndependentAssortmentappliestowhichofthefollowing?
A.Theinheritancepatternoftwogenesthatlieatoppositeendsofachromosome.
B.Theinheritancepatternoftwoallelesofthesamegene.
C.Theinheritancepatternoftwogenesthatresideondifferentautosomalchromosomes.
D.TheinheritancepatternofgenesthatlieontheXandYchromosomes.
5.Inflieseyedevelopmentisgovernedbytheeyelessgene.Fliesthatareeither
homozygousorheterozygousfortheEyallelehavenormaleyeswhilefliesthatare
homozygousfortheeyallelelackeyes.IfEy/eymalesarematedtoey/eyfemaleswhat
percentageoftheprogenywilllackcompoundeyes?
A.0%
B.25%
C.50%
D.75%
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6.TheNotchgenecontrolstheshapeoftheflywing.TheNalleleisdominantandgives
normalwingswhilethenalleleisrecessiveandgivesasmallnotchinthewingblade.
Imaginethatyouarematingmalesthatarehomozygousforthenallelewithfemalesthat
areheterozygousforbothalleles.Whilescreeningtheprogenyforwingshapeyounotice
that50%ofthemalesand50%ofthefemaleshavenotchedwings.Whereisthegenefor
wingshapelocated.
A.Ononeofthethreeautosomes
B.Xchromosome
C.Ychromosome
D.cannotbedeterminedwiththislevelofinformation
7.Inclasswetalkedaboutavarietyofpepperscalledstoplightpeppers.Theyarenamed
thiswaysincetheycomeinred,yellowandgreenvarieties(brownpeppersexistaswell).
Basedonourclassdiscussionwhichofthefollowingbestdescribestheinheritanceofcoat
color?
A.Themultiplecolorsaretheresultofincompleteorco‐dominance
B.ThegeneforpeppercolorislocatedontheXchromosomesomalesandfemalesproduce
differentpeppercolors.
C.Multiplegeneslocatedontheautosomesregulatethecolorofpeppers.
D.Thecolorofthepepperisnotgeneticallyregulated–thecolorsaredeterminedbythe
environmentaltemperature.
8.Achromosomecontainshundredsifnotthousandsofgenes.AlfredSturtevantusedthe
processofrecombinationtodeterminetherelativepositionofgenesalongthelengthof
eachDrosophilachromosome.Whichofthefollowingbestdescribestherelationship
betweengenesthatarelocatedonthesamechromosome?
A.Genesthatresideclosetogetheronachromosomerecombineatalowerfrequencythangenes
thataresituatedfarapartfromeachother.
B.GenesonthesamechromosomefollowMendel’sLawofIndependentAssortmentsothe
recombinationrateis100%.
C.Thedistancebetweentwogenesisinverselyproportionaltotherecombination/linkagerate.
D.Recombinationdoesnotoccurbetweengenesonthesamechromosome–onlybetweengenes
onnon‐homologouschromosomes.
9.SeymourBenzerusedbacteriophagetostudytheprocessofrecombination.Oneofhis
majoraccomplishmentswastodeterminethatrecombinationoccursatthelevelofthe
nucleotide.BasedonthisinformationandyourknowledgeofthestructureofDNAwhichof
thefollowingisatruestatement?
A.Recombinationoccursonlyatnucleotidesthatliebetweengenessoastopreventtheinduction
ofmutations.
B.Theprocessofrecombinationoccursonlyatnucleotidesthatlinethemajorgroove
C.RecombinationoccursonlyinDNAthatisfoundintheZconformation.
D.Recombinationcanhappenanywherealongthechromosomeincludingwithingenes
themselves.
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10.Whendoesrecombinationtakeplace?
A.Prophaseofmitosis
B.ProphaseofMeiosisI
C.MetaphaseofMeiosisII
D.G1ofbothMeiosisIandMeiosisII
11.Duringclassweintroducedourselvestoanumberofmodelsystems.Inthese
discussionswetalkedaboutafewoftheirpropertiesandthetypesofprocessesthateach
modelsystemisusedtostudy.Basedonthesediscussionswhichofthefollowingwouldbe
themostappropriateforstudyingmetastatictumors?
A.Drosophila
B.C.elegans
C.Mouse
D.Arabidopsis
12.Whichofthefollowingmodelsystemswouldbebestsuitedforstudyingpain
perception?
A.C.elegans
B.Drosophila
C.Arabidopsis
D.AandB
13.Whichofthefollowingwouldbethemostappropriatemodelsystemforstudyingearly
developmentalprocessessuchasblastulaformationinavertebrate?
A.Drosophila
B.Mouse
C.Xenopus
D.C.elegans
14.FredrickGriffithusedtwobacterialstrains(onepathogenicandonenon‐pathogenic)
andamousetodiscoverthe“TransformingPrinciple”.Basedonyourknowledgeofhis
experimentswhichofthefollowingwasthekeyexperimentalstepindeterminingthatthe
non‐pathogenic(R)strainwastransformedbyhereditarymaterialfromthepathogenic(S)
strain?
A.Livenon‐pathogenic(R)andpathogenic(S)bacterialstrainsweremixedataratioof1:5prior
toinjectionintothemouse.
B.ThepathogenicSstrainwasheatkilledpriortomixingwiththenon‐pathogenicRstrain.
C.AmousethatwasresistanttothepathogenicSstrainwasselectedforuseintheexperiment.
D.Thenon‐pathogenic(R)andpathogenic(S)strainswerebothheatkilledpriortoinjectioninto
themouse.
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15.OswaldAveryrepeatedGriffith’sexperimentsbutmodifiedthemtoshowthatthe
transformingagentwasactuallynucleicacid.Basedonyourknowledgeofhisexperiments
whatwasthekeystepindeterminingthatthehereditarymaterialwasnucleicacid?
A.Nucleicacidwasisolatedfrompathogenic(S)bacteriaandmixedwiththenon‐pathogenic(R)
bacteriapriortoinjectionintothemouse.
B.Nucleicacidfromlivenon‐pathogenic(R)strainswereremovedandreplacedwithnucleicacid
frompathogenic(S)strain.Thegeneticallymodifiedstrainwastheninjectedintothemouse.
C.Thegenomeofthenon‐pathogenic(R)strainwasgeneticallymodifiedtobenearlyidenticalto
thatofthepathogenic(S)strain.
D.Nucleicacidfrompathogenic(S)bacteriawasdirectlyinjectedintothemouse.
16.MarthaChaseandAlfredHersheyusedbacteriophageandbacterialcellsto
independentlydeterminethatnucleicacidswerethetransformingagent.Basedonyour
knowledgeoftheirexperimentswhatwasthekeystepindeterminingthatthenucleicacid
isthehereditarymaterial?
A.DNAwasmarkedwithradio‐labeledriboseandtheproteincoatsweremarkedwithradio‐
labeledaminoacids
B.Thebacteriophageswereheatkilledpriortobebeingmixedwiththelivebacterialcells.
C.Nucleicacidfromheatkilledbacteriophageswereinjectedintomice.
D.Theemptyproteincoatswereremovedfromthebacterialcellsafterthenucleicacidgenome
wasinjectedintothebacterialcells.
17.SeveralresearchershavediscoveredthatDNAismadeupoffournucleotides:adenine,
guanine,cytosineandthymine.EdwinChargaffmeasuredtheamountofthesefour
nucleotidesfromavarietyofdifferentcelltypesfromseveraldistinctmodelsystems.
Whichofthefollowingisatruestatement?
A.Theratioofpurinestopyrimidinesis1:1
B.Theamountofeachnucleotideisthesameinallsomaticandgermcellswithinanorganism.
C.Eachcelltypecontainsanequalamountofthefournucleotides.
D.Theamountofeachnucleotideisthesameinallcellswithinallmodelsystems.
18.WatsonandCricksolvedthestructureofDNA(withthehelpofRosalindFranklin).
FromEdwinChargraff’sexperimentsandthesolutionoftheDNAstructureitwasclearthat
thenucleotidesbasepairinveryspecificpatterns.Whichofthefollowingbase‐pairing
scenarioswouldviolatetherulesthatgoverntheproperstructureofthedoublehelix?
A.purine:pyrimidine
B.A:T
C.G:C
D.purine:purine
19.Nucleotidesalongasinglepolynucleotidechainareboundbywhichofthefollowing
typeofbond?
A.Hydrogenbonds
B.Phosphodiesterbonds
C.Covalentbonds
D.Aldehydelinkages
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20.TranscriptionfactorsbindtoDNAandcaneitheractivateorrepresstranscription.
WhichpartoftheDNAdoublehelixiscontactedbythealphahelicalsegmentsofDNA
bindingproteins?
A.Theminorgroove
B.Thedeoxyribosesugarbackbone
C.Thephosphodiesterlinkages
D.Themajorgroove
21.ThestructureofDNAdiffersslightlyfromthatofRNA.Whichofthefollowingisatrue
statementregardingthesestructures?
A.DNAusesadeoxyribosesugarwhileRNAusesaribosesugar.
B.DNAcontainsathyminebasewhileRNAcontainsauracilbase
C.RNAismainlysinglestrandedwhileDNAisalwaysfoundinadoublehelix
D.alloftheabove
22.ThereareseveralspeciesofRNAwithinacell.Whichofthefollowingcodesforprotein?
A.messengerRNA(mRNA)
B.transferRNA(tRNA)
C.ribosomalRNA(rRNA)
D.ribozymes
23.WhichofthefollowingblockstranslationbybindingtomRNAandforminglocalareasof
doublestrandedRNA?
A.ribozymes
B.transferRNA(tRNA)
C.ribosomalRNA(rRNA)
D.microRNAs
24.WhichofthefollowingRNAsarethepredecessorstoproteinenzymesandcanfunction
asenzymestocleavebothRNAandprotein?
A.microRNAs
B.ribozymes
C.messengerRNAs(mRNA)
D.transferRNA(tRNA)
25.DuringwhatphaseofthecellcycledoesDNAreplicationoccur?
A.Interphase
B.Prophase
C.Metaphase
D.Anaphase
26.Duringwhatphaseofthecellcycledochromosomescondense?
A.Interphase
B.Prophase
C.Metaphase
D.Telophase
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27.Whichofthefollowingiskeytophysicallyseparatingchromosomesintodaughtercells?
A.Actinfilaments
B.Microtubulefilaments
C.Thenucleus
D.Mitochondria
28.Atwhatpointdocellsexitfromthecellcycleandgoontodifferentiate?
A.G1
B.S
C.G2
D.M
29.Down’sSyndrome,Kleinfelter’sSyndromeandTurner’sSyndromeareallchromosomal
abnormalities.Whendothesemistakesinchromosomalsegregationarise?
A.Mitosis
B.MeiosisI
C.MeiosisII
D.MeiosisIorII
30.Whatisthegeneticmake‐upofanindividualwithKleinfelter’s?
A.XO
B.XYY
C.XXY
D.OY
31.Whatwouldbetheresultifmeiosis2wereeliminated?
A.Theprocessofrecombinationorcrossing‐overwillbeeliminated
B.Theprogenywillbehaploid(1N)
C.Theprogenywillbetetraploidor4N
D.Therewillbenochangetothegeneticmake‐upoftheprogeny(2N)
32.TheDNAdoublehelixiswoundaroundhistones.ThisallowsforDNAtobecondensed
duringcelldivisionandfortheinhibitionofgenetranscription.Whichofthefollowingisa
truestatementabouthistone–DNAinteractions?
A.HistonesinteractwithDNAattheminorgroove.
B.Histone–DNAbindingisbasedonchargeinteractionsandnotonrecognitionofspecificDNA
sequences.
C.ModificationofthehistoneN‐terminaltailcanalterhistone–DNAbinding.
D.Alloftheabove
33.WhatistheeffectontheoverallrateoftranscriptionwithinacellifthelevelofHistone
AcetylTransferase(HAT)proteinsisreducedbymutations?
A.Increase
B.Decrease
C.Nochangeintranscriptionwillbeobserved
D.Therewillbelocalizedincreasesatsomegenesandlocalizeddecreasesatothergenes.
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34.Whatwouldbetheeffectontheoverallrateoftranscriptionwithinacellifthelevelsof
HistoneDeAcetylase(HDAC)proteinswereincreased?
A.Increase
B.Decrease
C.Nochangeintranscriptionwillbeobserved
D.Therewillbelocalizedincreasesatsomegenesandlocalizeddecreasesatothergenes.
35.Inthearticle“Inthebeginning….”StanleyMillerisdescribedastestingthehypothesis
thatlifebeganintheatmosphere.Hepassedanelectriccurrentthroughaflaskcontaining
boilingwaterandseveralgasesthatwerethoughttoexistduringtheearliesttimeson
Earth.Whichofthefollowingmoleculeswerecreatedinthisexperiment?
A.nucleicacids
B.aminoacids
C.lipids
D.primitiveorganelles
36.Inthearticleentitled“Nearlythere…”CraigVentoriscreditedwithcreatingthefirst
artificialorganism.Whichofthefollowingaretruestatementsfromthearticle?
A.VenterinsertedarecreatedversionoftheM.genitaliumgenomeintoabacterialcellthathadits
ownDNAremoved.
B.Venterwantstodeterminethe“minimalgenome”–abacterialcellwithonlythegenes
absolutelynecessaryforsurvivalandreproduction.
C.Syntheticbacteriacanbeusedtoproducemolecularproductssuchasfuelsforcarsandjets.
D.Alloftheabove
37.Basedonyourunderstandingofthearticleentitled“Cavemen,ChimpsandUs”whichof
thefollowingstatementsistrue?
A.Neanderthalsandmodernhumansshareacommonancestorthatlivedabout400,000yearsago
whilehumansandchimpanzeeshavebeenevolvingapartfornearly5‐7millionyears.
B.TherecentdivergenceofNeanderthalsandmodernhumansmeansthatthereareveryfew
differencesbetweenthetwogenomes.
C.ThefewdifferencesbetweentheNeanderthalandhumangenomesshouldberesponsiblefor
traitssuchaslanguage,brainsizeandhigherorderthinking.
D.Alloftheabove
38.Inthearticleentitled“Closecousins”itisarguedthathumanscouldhaveinterbredwith
chimpanzeesatsomepointinthedistantpast.Whichofthefollowingisusedtosupport
thisconclusion?
A.TheXchromosomesofhumansandchimpanzeesaremoresimilarthanthenon‐sex
chromosomeswhichsuggeststhatviablehuman‐chimphybridsexisted.
B.Thefossilrecordindicatesthataskulldatedtobebetween6mand7.4myearsoldhashuman‐
likefeatures.
C.Ananalysisofthehumanandchimpgenomeindicatesthereareregionsofveryhighsequence
similarity.
D.Alloftheabove
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39.Inthearticleentitled“Theoriginofspeakies”itissuggestedthatNeanderthalscan
speak.Whichofthefollowingisevidencethatismayinfactbetrue?
A.Neanderthalshadahyoidbonewhichisimportantintongueandlarynxmovement.
B.Neanderthalshadalargehypglossalcanalwhichisusedbynervestoenervatethetongue.
C.NeanderthalshadacopyoftheFOXP2genewhichisthoughttobeimportantforspeechand
languageinmodernhumans.
D.Alloftheabove
40.WhichteamdoyouwanttowintheSuperBowl?InLasVegasthePackersarefavored
overtheSteelersby2.5points.IamcurioustoseewhatthespreadishereinBloomington.
(youwillgetcreditforeitheranswer).
A.PittsburghSteelers
B.GreenBayPackers
EXAM1ANSWERKEY
1.A
2.B
3.B
4.C
5.C
6.D
7.C
8.A
9.D
10.B
11.C
12.D
13.C
14.B
15.A
16.D
17.A
18.D
19.B
20.D
21.D
22.A
23.D
24.B
25.A
26.B
27.B
28.A
29.D
30.C
31.C
32.D
33.B
34.B
35.B
36.D
37.D
38.D
39.D
40.AandB