Upload
others
View
5
Download
0
Embed Size (px)
Citation preview
NEETREVISIONSERIES
PRINCIPLEOFINHERITANCEANDVARIATION
ReviseMostImportantQuestionstoCrackNEET2020
DownloadDoubtnutNow
Q-1-35214208
A person with 47 chromosomes due to an additional Y-chromosome
suffers from a condition called
(A)Down'ssyndrome
(B)Superfemale
(C)tuner'ssyndrome
(D)klinefelter'ssyndrome
CORRECTANSWER:D
SOLUTION:
HFKlinefelterfirstdescribedthisconditionin1942.The
chromosomenumberis2n=47withtheformula44A+
XXY.
Phenotypicallytheseindividualsaremales,buttheycan
showsomefemalesecondarysexualcharacteristicsand
areusuallysterile.
WatchVideoSolutionOnDoubtnutApp
Q-2-30701408
Chromosomes found in the salivvaary glands of Drosophila are
(A)Lampbrush
(B)Polytene
(C)Supernumerary
(D)B-chromosomes.
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-3-35214028
Among the following characters, which one was not considered by
Mendel in his experiments on pea?
(A)Stem-TallorDwarf
(B)Trichomes-GlandularorNon-glandular
(C)Seed-GreenorYellow
(D)Pod-inflatedorConstricted
CORRECTANSWER:B
SOLUTION:
Trichomesaretheepidermaltissuesstructure.When
epidermalcellsbecomeglandularhair,itiscalled
trichome.Thischaracterwasnotamongsttheseven
charactersofpea,whichmendelselectedforhis
hybridisationexperiments.
WatchVideoSolutionOnDoubtnutApp
Q-4-30701434
Complete linkage is found in
(A)Birds
(B)Snakes
(C)FemaleDrosophila
(D)MaleDrosphila
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-5-35214050
The term ''linkage'' was coined by
(A)THMorgan
(B)TBoveri
(C)GMendel
(D)WSutton
CORRECTANSWER:A
SOLUTION:
ThetermlinkagewascoinedbyTHMorgan.Hecarried
outseveraldihybridcrossesinDrosophilatostudy
genesthatweresex-linked.Hedescribedthephysical
associationofgenesonachromosome.
WatchVideoSolutionOnDoubtnutApp
Q-6-35214033
Which of the following most appropriately describes haemophilia?
(A)X-linkedrecessivegenedisorder
(B)Chromosomaldisorder
(C)Dominantgenedisorder
(D)Recessivegenedisorder
CORRECTANSWER:A
SOLUTION:
HaemophiliaisX-linkedrecessivegenedisorder.Itisa
bloodclottingdisorderandshowscriss-cross
inheritance.Inthis,charactersfromfatherare
transmittedtodaughterandfrommothertoson.
WatchVideoSolutionOnDoubtnutApp
Q-7-30701414
A chromosome with sub terminal centromere is
(A)Acentric
(B)Acrocentric
(C)Metacentric
(D)Telocentric
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-8-35214046
A true breeding plant is
(A)onethatisabletobreedonitsown
(B)producedduetocross-pollinationamongunrelated
plants
(C)nearhomozygousandproducesoffspringofitsown
kind
(D)alwayshomozygousrecessiveinitsgenetic
constitution
CORRECTANSWER:C
SOLUTION:
Atruebreedingplant(pureline)hashomozygousgenes
foracharacter(e.g.TTfortallorttfordwarf).Italways
producesoffspringswhicharetrue(pure)forits
characters.
WatchVideoSolutionOnDoubtnutApp
Q-9-30701403
Term chromosome was coined by
(A)Hofmeister
(B)Sutton
(C)Boveri
(D)Waldeyer
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-10-35214272
Two linked genes a nad b show 20% recombination the indivsuls of
a hybrid cross between ++/++ X ab/ab shaoll show gemetes:
(A)
(B)
(C)
(D)
CORRECTANSWER:C
SOLUTION:
+ + 80: ab : 20
+ + 50: ab : 50
+ + 40:ab40 : + a10 :+ b : 10
+ + 30:ab30 : + a20 :+ b : 20
Thegametesofadihybridcrossbetween
willbe++40:ab40:+a10:+
b:10
WatchVideoSolutionOnDoubtnutApp
Q-11-35214084
Which one of the following cannot be explained on the basis of
Mendel's Law of Dominance?
(A)Thediscreteunitcontrollingaparticularcharacteris
calledafactor
(B)Outofonepairoffactorsoneisdominant,andthe
otherrecessive
(C)Allelesdonotshowanyblendingandboththe
charactersrecoverassuchin -generation
(D)Factorsoccurinpairs
+ + / + + × ab/ab
F2
CORRECTANSWER:C
SOLUTION:
Outofthefollowingstatement(c)isincorrectbecause
thelawofdominancedoesnotoccuruniversally.After
Mendelseveralcaseswererecordedbyscientists,
whereacleardeviationfromlawofdominancewas
seen.
Where, hybridsexhibitedamixtureorblendingof
characteroftwoparents,thecaseisconsideredasthat
ofincompletedominanceorblendinginheritance.It
simplymeansthattwogenesofallelomorphicpairare
notrelatedasdominantorrecessive,butarenotrelated
asdominantorallelomorphicpairarenotrelatedas
dominantorrecessive,buteachofthemexpressesitself
partially.Inthecaseof4O'clockplant,whenplantswith
redflowersarecrossedwithplantshavingwhiteflower,
F1
the hybridsbearpinkflower.Whenthesepinkflowers
areselfpollinated,theydevelopred,pinkandwhite
flowersintheratioof1:2:1respectively.
WatchVideoSolutionOnDoubtnutApp
Q-12-30701443
Crossing over occurs at
(A)Singlestrandsatgeofchroomosmesduringpropase
(B)Twostrandstageduringzygotene
(C)MetaphaseIIofmeiosis
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-13-18704887
F1
Howmany types of gemete will be produced by an individual
having genotype AaBbcc:
(A)Four
(B)Three
(C)Two
(D)One
CORRECTANSWER:A
SOLUTION:
Na
WatchVideoSolutionOnDoubtnutApp
Q-14-35214077
Select the correct statement from the ones given below with respect
to dihybrid cross.
(A)Tightlylinkedgenesonthesamechromosomeshow
higherrecombinations
(B)Genesfarapartonthesamechromosomeshowvery
fewrecombinations
(C)Geneslooselylinkedonthesamechromosome
showsimilarrecombinationsasthetightlylinkedones
(D)Tightlylinkedgenesonthesamechromosomeshow
veryfewrecombinations
CORRECTANSWER:D
SOLUTION:
Morganandhisgroupfoundthatwhengeneswere
groupedonthesamechromosome,somegeneswere
verytightlylinked(showedverylowrecombination),
whileotherswerelosselylinked(showedhigher
recombination).Recombinationisaprocessof
rearrangementofgenesduringmeiosissothatagamete
containsahaploidgenotypewithanewgene
combination.
WatchVideoSolutionOnDoubtnutApp
Q-15-35214205
HJ Muller was awarded Noble Prize for his
(A)discoverythatchemicalscaninducegenemutations
(B)discoverythationizingradiationscaninducegene
mutations
(C)workongenemappinginDrosophila
(D)effortstopreventstheuseofnuclearweapons
CORRECTANSWER:A
SOLUTION:
HJMullerwasawardedNobelPrizefordiscoveringthat
ionizingradiationscaninducegenemutations.
WatchVideoSolutionOnDoubtnutApp
Q-16-18704910
In a population of 1000 individuals 360 belong to genototype AA
,480 to Aa and the remaining 160 to aa Based on this data ,the
frequency of allele A in the population is
(A)0.6
(B)0.7
(C)0.4
(D)0.5
CORRECTANSWER:A
SOLUTION:
(a)AccordingtoHardyWeinbergprinciple
+2pq+q^(2)=1,(p+q)^(2)=1 P^(2)=360
P^(2)=36 q^(2)=160 q^(2)=16
q=sqrt(.16)=.4.As""p+q=1`
so,pis0.6.
WatchVideoSolutionOnDoubtnutApp
Q-17-35214907
[" 8.A man,after a tour,finds that he had spent "],[" every day as
many rupees as the number of "],[" days he had been on tour.How
long did his "],[" tour last,if he had spent in all "21,296" ? "]
WatchVideoSolutionOnDoubtnutApp
P 2 ( ∀ )outof1000 ∈÷ idual or
outof100 outof1000 or
outof100so,
Q-18-35214076
Which one of the following conditions correctly describes the
manner of determining the sex in the given example?
(A)XOtypeofsexchromosomesdeterminemalesexin
grasshopper
(B)XOconditioninhumansasfoundinTurner
syndrome,determinesfemalesex
(C)Homozygoussexchromosomes(XX)producemale
inDrosophila
(D)Homozygoussexchromosomes(ZZ)determine
femalesexinbirds.
CORRECTANSWER:A
SOLUTION:
GrasshopperisanexampleofXOtypeofsex
determinationinwhichthemaleshaveonlyoneX-
chromosomebesidestheautosomes,whereasfemales
haveapairofX-chromosomes.
WatchVideoSolutionOnDoubtnutApp
Q-19-18705022
Lathyrus odoratus is an example of which of the following genes
(A)Supplementrygenes
(B)Complementrygenes
(C)Lethelgenes
(D)Condominantgenes
CORRECTANSWER:B
SOLUTION:
(b)
Incomplementarygeneaction,9:7ratioisobtainedin
inwhichtwodominantgenesareresponsibleforred
flowercolour.
WatchVideoSolutionOnDoubtnutApp
Q-20-35214214
The polytene chromosomes were discovered for the first time in
(A)Drosophila
(B)Chironomus
(C)Muscanebulo
(D)Muscadomestica
CORRECTANSWER:B
CCppWhite
×↓
CcPp
Red
ccPPWhite
F2
SOLUTION:
Polytenechromosomeswerefirsttimediscoveredbythe
ItaliancytologistEGBalbiani(1881)inthesalivarygland
cellsofChironomuslarva.
WatchVideoSolutionOnDoubtnutApp
Q-21-30701441
Greater is the distance between the two genes on a chromosome
(A)Greateristelinkagestrength
(B)Lesseristhelinkagestreangth
(C)Linikagestrengthremainsunchangeed
(D)Thereisnorelationshipbetweenthetwo
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-22-35214035
A cell at telophase stage is observed by a student in a plant brought
from the field. He tells his teacher that this cell is not like other cells
at telophase stage. There is no formation of cell plate and thus the
cell is containing more number of chromosomes as compared to
other dividing cells. This would result in
(A)polyploidy
(B)somaclonalvariation
(C)polyteny
(D)aneuploidy
CORRECTANSWER:A
SOLUTION:
Polyploidcellshaveachromosomenumberthatismore
thandoublethehaploidnumber,e.g.Triticumaestivum
(wheat)isahexaploid(6n).
WatchVideoSolutionOnDoubtnutApp
Q-23-30701453
The blue green algae and bacteria contain
(A)Onelinkagegroup
(B)Twolinkagegroups
(C)Threeelinkagegroups
(D)Noneoftheabove
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-24-35214199
The hereditary material (DNA) present in the bacterium E.coli is
(A)singlestrandedRNA
(B)doublestrandedRNA
(C)singlestrandedDNA
(D)doublestrandedDNA
CORRECTANSWER:D
SOLUTION:
Bacterialchromosomeissingle,circulardoublestranded
DNAmolecule.
WatchVideoSolutionOnDoubtnutApp
Q-25-30701409
:
A giant chormosome with a number of chromonemata is
(A)Lampbrushchromosome
(B)Heterochromosome
(C)supernumerarychromosome
(D)`Polytenechromosome
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-26-35214045
If a colourblind man marries a woman who is homozygous for
normal colour vision, the probability of their son being colourblind
is
(A)0
(B)0.5
(C)0.75
(D)1
CORRECTANSWER:A
SOLUTION:
Ifacolourblindmanmarriesawomanwhois
homozygousfornormalcolourvision,theprobailityof
theirsonbeingcolourblindiszero.Colourblindnessisa
recessivesex-linkedtraitinwhichtheeyefailsto
distinguishbetweenappearsonlywhenbothsex
chromosomescarryrecessivegene .However,
inhumanmales,thedefectappearsduetosingle
recessivegene becauseYchromosomedoes
notcarrygeneforcolourvision.Thisdiseaseshows
criss-crossinheritance.
(X cX c)
(X cY )
Thus,thereiszeroprobabilityofsonbeingcolourblind.
Hence,option(a)iscorrect.
WatchVideoSolutionOnDoubtnutApp
Q-27-18705039
Incomplete dominance is found in
(A)Pisumsativum
(B)Antirrhinummajus
(C)Both(a)and(b)
(D)Noneofthese
CORRECTANSWER:B
SOLUTION:
(b)IncompletedominanceisfoundinAntirrhinummajus
(snapdragon)andMirabillisjalapa(4O'clockplant).
WatchVideoSolutionOnDoubtnutApp
Q-28-35214203
Different mutations referrable to the same locus of chromosome
give rise to
(A)pseudoalleles
(B)polygenes
(C)oncogenes
(D)multiplealleles
CORRECTANSWER:D
SOLUTION:
Thephenomenonofmultipleallelismisthesimultaneous
occurrenceofmorethantwoalleles(multiplealleles)at
agivengenelocus.Anymutationoccurringwithina
gene(atthesamelocus)willgiverisetoanewformor
newalleleofthatgene.
WatchVideoSolutionOnDoubtnutApp
Q-29-35214066
If both parents are carriers for thalassaemia, which is an autosomal
recessive disorder, what are the chances of pregnancy resulting in
an affected child?
(A)Nochance
(B)0.5
(C)0.25
(D)1
CORRECTANSWER:C
SOLUTION:
Inthegivenquestionsincebothparentscarrya
haemoglobinopathytraitofthalassemiatheriskis25%
foreachpregnancyforanaffectedchild.
RR-Unaffected(25%)
Rr-Carrier(50%)
rr-Affected(25%)
So,thechancesofpregnancyresultinginanaffected
childis25%.
WatchVideoSolutionOnDoubtnutApp
Q-30-30701415
A chromosome with centromere near the middle is called
(A)Metacentric
(B)Submetacentric
(C)Acrocentric
(D)Telocentric
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-31-35214252
One gene pair hides the effect of another. The pheomenon is:
(A)epistasis
(B)dominance
(C)mutation
(D)Noneofthese
CORRECTANSWER:A
SOLUTION:
Epistasisisthephenomenonbywhichagene
suppressesthephenotypicexpressionofanon-allelic
gene.
WatchVideoSolutionOnDoubtnutApp
Q-32-18705056
Coupling and repulsion are the two faces of
(A)Crossingover
(B)Linkage
(C)Chiasmata
(D)Mutation
CORRECTANSWER:B
SOLUTION:
(b)Thetendencyofparentalcombinationstoremain
together,whichisexpressedintermsoflowfrequencyof
recombinationsiscalledlinkage.
WatchVideoSolutionOnDoubtnutApp
Q-33-35214032
A disease caused by an autosomal primary non-disjunction is
(A)down'ssyndrome
(B)klinefelter'ssyndrome
(C)tuner'ssyndrome
(D)sickle-cellanaemia
CORRECTANSWER:A
SOLUTION:
Non-disjunctionisthefailureofchromosomestodisjoin
orseparateandmoveawaytooppositepoles.Non-
disjunctionof21stchromosomeduringoogenesisisthe
causeofdown'ssyndrome.Itoccursduetothe
presenceofanadditionalcopyofchromosomeno.21
(trisomyof21stchromosome)ishumans.
WatchVideoSolutionOnDoubtnutApp
Q-34-30701457
Maize has 10 pairs of chromosomes.How many linkage groups does
it have ?
(A)20
(B)10
(C)5
(D)40
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-35-18704882
Mendal was te native of
(A)France
(B)Sweden
(C)India
(D)Austria
CORRECTANSWER:D
SOLUTION:
(d)Hewasansabbort(heat)ofAugustionmonasteryof
St.Thomasatbrun,AugustionmonasteryofSt.thomsat
brunn,Austriain1847
WatchVideoSolutionOnDoubtnutApp
Q-36-35214063
Which of the following statements is not true of two genes that
show 50% recombination frequency?
(A)Thegenesmaybeondifferentchromosomes
(B)Thegenesaretightlylinked
(C)Thegenesshowindependentassortment
(D)Ifthegenesarepresentonthesamechromosome,
theyundergomorethanonecrossoversineverymeiosis
CORRECTANSWER:B
SOLUTION:
Outofthegivenstatements(b)isincorrectbecausethe
tightlylinkedgenesonchromosomesshow100%
parentaltypesand0%recombinants.Twogenesthat
undergoindependentassortmentindicatedbya
recombinantfrequencyof50%areeitheronnon-
homologouschromosomesorlocatedfarapartina
singlechromosome.
Asthedistancebetweentwogenesincreases,crossover
frequencyincreases.Morerecombinantgametes,fewer
parentialgametes.
WatchVideoSolutionOnDoubtnutApp
Q-37-35214061
A human female with Turner's syndrome
(A)has45chromosomeswithXO
(B)hasoneadditionalX-chromosome
(C)exhibitsmalecharacters
(D)isabletoproducechildrenwithnormalhusband
CORRECTANSWER:A
SOLUTION:
AhumanfemalewithTurnersyndromehastheabsence
ofoneoftheX-chromosome,i.e.45withXO(or44+
XO).Turnersyndromeisachromosomalconditionthat
affectsthedevelopmentinfemales.Themostcommon
featureofTurnersyndromeisshortstature,which
becomeevidentbytheageof5.Aneasilylossof
ovarianfunctionisalsoverycommon.
Theovariesdevelopenormallyatfirst,buteggcells
usuallydieprematurelyandmostoveriantissue
degeneratesbeforebirth.
WatchVideoSolutionOnDoubtnutApp
Q-38-18705088
When synapsis is complete all along the chromosomes, the cell is
said to have entered a stage called
(A)Zygotene
(B)Pachytene
(C)Diplotene
(D)Diakinesis
CORRECTANSWER:B
SOLUTION:
(b)Thesynapsis,pairingofhomologouschromosomes
takesplaceduringzygotene.Synapsisresultsinthe
formationofbivalentsduringzygotene.Theformationof
specialproteionaceousstructurecalledsynaptonemal
complexoccur.Afterzygotenestagecellentersin
pachytenestageinwhichthebivalentsbecome
spiralled,shortenedandthickened.
WatchVideoSolutionOnDoubtnutApp
Q-39-35214247
Out of 8 ascospores formed in Neutrospora the arrangement is 2a :
4a : 2a showing
(A)nocrossingover
(B)somemeiosis
(C)secondgenerationdivision
(D)firstgenerationdivision
CORRECTANSWER:C
SOLUTION:
InNeurosporaaftercrossingoverbetweenthegeneand
centromere,thepairedarrangementofascosporesisAA
aaaaAAor2a:4a:2a.Thisisknownassecond
divisionsegregation.
WatchVideoSolutionOnDoubtnutApp
Q-40-18705108
the long and short arms of chromosome are designated respectively
as :
(A)pandqarms
(B)qandparms
(C)mandparms
(D)landsarms
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-41-35214093
Point mutation involves
(A)insertion
(B)changeinsinglebasepair
(C)duplication
(D)deletion
CORRECTANSWER:B
SOLUTION:
Thepointmutationsinvolvealterationsinthestructureof
genebyalteringthestructureofDNA,i.e.changein
singlebasepair.Pointmutationsareoftwotypes,i.e.
basepairsubstitutionandframeshiftsubstitution.
Insertionistheadditionofoneormorenitrogenous
basestoanucleotidechain.
Duplicationisthepresenceofoneblockofgenesmore
thanonceinahaploidcomponent.
Deletionistheremovalofoneormorenitrogenous
basesfromanucleotidechain.
WatchVideoSolutionOnDoubtnutApp
Q-42-18705105
The distance between the genes a,b,c and d in mapping units are a-
d=3,5, b-c=1,a-b=6,c-d=1.5, a-c=5. Find out the sequence of
arrangeent of these genes
(A)acdb
(B)abcd
(C)acbd
(D)adcb
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-43-35214197
A mutation at one base of the first codon of a gene produces a non-
functional protein. Such a mutation is referred as
(A)frameshiftmutation
(B)mis-sensemutation
(C)non-sensemutation
(D)reversemutation
CORRECTANSWER:B
SOLUTION:
Ifmutationatonebaseofthefirstcodonofagenetakes
placethenallthesubsequentcodonswillbeoutof
register(geneticcode).Thisresultsintotheformationof
mis-senseproteinwhichisformedduetothemutationin
thefirstbaseoffirstcodonandthuscalledmissense
mutation.
WatchVideoSolutionOnDoubtnutApp
Q-44-18705123
Heterochromatin remains condensed in which part of chromosome
(A)secondaryconstrictions-I
(B)secondaryconstrictions-II
(C)Telomeres
(D)Bothaandb
CORRECTANSWER:A
SOLUTION:
(a)Eachchrosomehasacentromere(primary
construction)butinsomecasessecondaryconstruction
isalsopresent,morespecificallycalledas'secondary
construction-II'.Itspositionisconstantforparticular
chromosomeheterochrmatiniscondensedinthisregion
.Inman'secondaryconstruction-II'ispresentin
chrosomenumber andY.Nuclear
organizeriscalled'secondaryconstruction-I'.
WatchVideoSolutionOnDoubtnutApp
1, 10, 13, 16
Q-45-35214089
Select the incorrect statement from the following
(A)linkageisanexceptiontotheprincipleof
independentassortmentinheredity
(B)galactosemiaisaninbornerrorofmetabolisms
(C)smallpopulationsizeresultsinrandomgeneticdrift
inapopulation
(D)baldnessisasexlimitedtrait
CORRECTANSWER:D
SOLUTION:
Outofthegivenstatements(d)isincorrectbecause
baldnessisnotasex-limitedtrait.
WatchVideoSolutionOnDoubtnutApp
Q-46-18705091
Chiasma shows the sites of
(A)Spindleformation
(B)Synapsis
(C)Crossingover
(D)Noneofthese
CORRECTANSWER:C
SOLUTION:
(c)Morganproposedthatchaismataleadtocrossing
overbybreakageandreunionofhomologous
chromosomes.
WatchVideoSolutionOnDoubtnutApp
Q-47-30701416
Puffs or balbiani rings in salivary gland chromsosomes are sites of
(A)DNAreplication
(B)DNAduplication
(C)RNAsynthesis
(D)Proteinsynthesis
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-48-18705079
What is the unit of crossing over
(A)Cistron
(B)Muton
(C)Recon
(D)Noneoftheabove
CORRECTANSWER:C
SOLUTION:
(c)Recon-Unitofrecombination
Muton-Unitofmutation
Cistron-Unitoffunction
WatchVideoSolutionOnDoubtnutApp
Q-49-35214038
Match the terms in column I with their description in column II and
choose the correct option.
(A)
(B)
(C)
(D)
CORRECTANSWER:A
SOLUTION:
Dominance-Expressionofonlyonealleleina
heterozygousorganism.
Codominance-Sidebysidefullexpressionofboth
alleles. resemblesbothparents.
ColumnI ColumnIIA. Dominance 1. ManygenesgovernasinglecharacterB. Codominance 2. InaheterozygousorganismonlyonealleleexpressesitselfC. Pleiotropy 3. InaheterozygousorganismbothallelesexpressthemselvesfullyD. Polygenicinheritance 4. Asinglegeneinfluencesmanycharacters
A B C D2 3 4 1
A B C D4 1 2 3
A B C D4 3 1 2
A B C D2 1 4 3
F1
Pleiotropy-Singlegenecanexhibitmultiplephenotypic
expression,e.g.,Phenylketonuria.
Polygenicinheritance-Manygenesgovernasingle
character,e.g.Humanskincolour.
WatchVideoSolutionOnDoubtnutApp
Q-50-35214041
Pick out the correct statements.
I. Haemophilia is a sex-linked recessive disease.
II.Down's syndrome is due to aneuploidy.
III. Phenylketonuria is an autosomal recessive gene disorder.
IV. Sickle-cell anaemia is an X - linked recessive gene disorder.
(A)IIandIVarecorrect
(B)I,IIIandIVarecorrect
(C)I,IIandIIIarecorrect
(D)IandIVarecorrect
CORRECTANSWER:C
SOLUTION:
Sickle-cellanaemiaisanautosomalrecessivegene
disorderinwhichsickle-celledRBCsareformedinstead
ofnormalones.Theycarryverylesscontentof as
theirhaemoglobinismalformed.Thepersonsuffering
fromthisdiseaseshowsymptomsofanaemia.
WatchVideoSolutionOnDoubtnutApp
Q-51-30701410
Lampbrush chormosome occur in
(A)Salivaryglands
(B)Lymphglands
O2
(C)Cancercells
(D)Oocytes
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-52-35214048
The mechanism that causes a gene to move from one linkage group
to another is called
(A)inversion
(B)duplication
(C)translocation
(D)crossingover
CORRECTANSWER:C
SOLUTION:
Translocationistheprocesscausingagenetomove
fromonelinkagegrouptoanother.Itistheseparationof
achromosomesegmentanditsuniontoanon-
homologouschromosome.Itisoftwotypes-simpleand
reciprocalInsimpletranslocationonechromosome
showsdeletionordeficiencywhileanonhomologous
chromosomecomestohaveanadditionalsegment.In
reciprocaltranslocationtwonon-homologous
chromosomesexchangesegmentsbetweenthemselves
tocreatenewlinkagegroupsinboththechromosomes
Hence,option(c)iscorrect.
WatchVideoSolutionOnDoubtnutApp
Q-53-30701417
Chromosome theory of inheritane was proposed by
(A)Sutton(1902)
(B)`Boveri(1902)
(C)BothSutton(1902)andBoveri(1902)
(D)Correns(1909)
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-54-30701462
Alkaptonurics excreate excess of
(A)Urine
(B)Albumen
(C)Malonycaeticacid
(D)Homogentisicacid
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-55-35214098
Two genes R and Y are located very close on the chromosomal
linkage map of maize plant. When RRYY and rryy genotypes are
hybridised, then segregation will show
(A)highernumberoftherecombinanttypes
(B)segregationintheexpected9:3:3:1ratio
(C)segregationin3:1ratio
(D)highernumberoftheparentaltypes
CORRECTANSWER:D
F2
SOLUTION:
HighernumberoftheparentaltypesformedwhenRRYY
andrryygenotypesarehybridisedgivingthecondition
thatRandYgenesarecloselylinked.Lawof
independentassortmentdoesnotapplicablewhenthe
geneofdifferentcharacteroccupythesame
homologouschromosomei.e.arelinkedgene.
WatchVideoSolutionOnDoubtnutApp
Q-56-18705213
"Nu body" was shown by
(A)Darlington
(B)Johanssen
(C)Woodcock
(D)TeminandBaltimore
CORRECTANSWER:C
SOLUTION:
(c)Woodcock(1973)observedthestructureof
chromatinunderelectronmicroscope.Hetermedeach
beadedstructureonchromosomeasnucleosome.
WatchVideoSolutionOnDoubtnutApp
Q-57-35214102
Test cross involves
(A)crossingbetweentwogenotypeswithrecessivetrait
(B)crossingbetweentwo hybrids
(C)crossingthe hybridwithadoublerecessive
genotype
F1
F1
(D)crossingbetweentwogenotypeswithdominanttrait
CORRECTANSWER:C
SOLUTION:
Thetestcrossinvolvesthecrossingof hybridwitha
doublerecessivegenotypicparent.Bytestcross,the
heterozygosityandhomozygosityoftheorganismcan
betested.
Thus,theoffspringwillbe100%dominant,ifthe
individualwhichcrossedwithrecessiveparent,i.e.(tt)
washomozygousdominantandratiowillbe50%
dominantand50%recessiveiftheindividualwas
heterozygousdominant.Indihybridtestcross,ratiowill
be1:1:1:1.
WatchVideoSolutionOnDoubtnutApp
F1
Q-58-18705270
Human blood groups are example of a
(A)Gradulism
(B)Cline
(C)Gradientofdiplodiy
(D)Polymorphism
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-59-18705212
The peroson who discovered 'Y' Chromosomes was
(A)McCarthy
(B)McClung
(C)GregorMendel
(D)NettiStevens
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-60-35214104
In which mode of inheritance do you expect more maternal
influence among the offspring?
(A)Autosomial
(B)Cytoplasmic
(C)Y-linked
(D)X-linked
CORRECTANSWER:B
SOLUTION:
Themorematernalinfluencecanbeexpectedinthe
cytoplasmicinheritance,i.e.theinheritanceofgenes
containedinthecytoplasmofacell,ratherthanthe
nucleus.
Thereasonisthatthefemalereproductivecellorthe
egghasalargeamountofcytoplasmcontainingmany
suchorganelleswhichcontaintheirowngenesandcan
reproduceindependently,e.g.mitochondriaand
chloroplastandwhichareconsequentlyincorporated
intothecytoplasmofallthecellsoftheembryo.
Themalereproductivecells(spermorpollen)consist
almostsolelyofanucleus.Cytoplasmicorganellesare
thus,notinheritedfromthemaleparent.
Thisiswhy,thecytoplasmicinheritanceisalsocalled
maternalinheritance.
AgenelocatedintheX-chromosomeissaidtobeX-
linkedanditsinheritanceiscalledX-linkedinheritance.
Inthis,amaletransmitshisX-chromosomeonlytohis
daughterswhileafemaletransmitsoneofherX-
chromosomestotheoffspringofbothsexes.
WatchVideoSolutionOnDoubtnutApp
Q-61-30701526
Theroy of heterogamesiss for sex determination was proposed by
(A)Morgan
(B)Darwin
(C)Correns
(D)Bridges
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-62-35214107
Phenotype of an organism is the result of
(A)mutationsandlinkages
(B)cytoplasmiceffectsandnutrition
(C)environmentalchangesandsexualdimorphism
(D)genotypeandenvironmentalinteractions
CORRECTANSWER:D
SOLUTION:
Phenotypeistheobservablecharacteristicsorthetotal
appearanceofanorganism.Itisdeterminedbyits
genes,therelationshipsbetweentheallelesandbythe
interactionduringdevelopmentbetweenitsgenetic
constitution(genotype)andtheenvironment.
WatchVideoSolutionOnDoubtnutApp
Q-63-30701497
The frequency of mutation in a species can be increased by the use
of
(A)X-rays
(B)UV-rays
(C)Nitrousacid
(D)Alltheabove
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-64-35214190
Loss of an X-chromosome in a particular cell, during its
development, results into
(A)diploidindividual
(B)triploidindividual
(C)gynandromorphs
(D)Both(a)and(b)
CORRECTANSWER:C
SOLUTION:
Gynandromorphsarethoseindividualsinwhichonepart
ofthebodyisfemalewhileanotherpartismale.It
occursduetotheirregularityinmitosisatthefirst
cleavageofthezygote.OneoftheX-chromosomesof
anXX(female)zygotelagsinthespindle,onedaughter
nucleusreceivesonlyoneX-chromosomes.whilethe
otherreceivestwoX-chromosomes.Amosaicbody
patternisthusestablishedwhichisknownas
gynandromorph.
WatchVideoSolutionOnDoubtnutApp
Q-65-35214113
A man and a woman, who do not show any apparent signs of a
certain inherited disease, have seven children (2 daughters and 5
sons). Three of the sons suffer from the given disease but none of
the daughters are affected. Which of the following mode of
inheritance do you suggest for this disease ?
(A)Autosomaldominant
(B)Sex-linkeddominant
(C)Sex-limitedrecessive
(D)Sex-linkedrecessive
CORRECTANSWER:D
SOLUTION:
Ingivenproblem,diseaseistheresultofsex-linked
recessivegenes.Asneithermannorwomanshows
signsofdiseaseitmeanswomanwouldbecarrierfor
disease.Intheirchildrennonofthedaughterssuffer
fromdisease,whilethesonsweresuffered,itmeans
daughtersarealsocarrier(i.e.X-linkedrecessive).
Suppose,genotypeofman=XY
Genotypeofwoman=
(d-diseasecausinggene)
XdX
Foreachdeliverytheprobabilityforeachcombinationis
25%.So,amongsevenchildren2normaldaughter,3
diseasedsonsand2normalsonsarepossible.
WatchVideoSolutionOnDoubtnutApp
Q-66-30701484
A classical example off allopolyploid is
(A)Brassica
(B)raphnobrassica
(C)Raphanius
(D)Alltheabove
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-67-35214138
When a cluster of genes shows linkage behaviour they
(A)donotshowindependentassortment
(B)inducecelldivision
(C)donotshowachromosomemap
(D)showrecombinationmeiosis
CORRECTANSWER:A
SOLUTION:
Linkedgenesdonotshowindependentassortment
becausetheyarelocatedonthesamechromosome.But
geneswhicharelocatedonthesamechromosomes
(calledlinkedgenes)donotassortindependently.Such
typeofgenesarecalledlinkedgenesandthis
phenomenoniscalledaslinkage.
WatchVideoSolutionOnDoubtnutApp
Q-68-30701477
Aneuplody is the term applied for the
(A)Genemutation
(B)chromosomalmutation
(C)Crhromosomalmutationsinvolvingtheadditionor
lossofoneormorechromoso9mes
(D)Chromosomalmutationinvolvingtheadditionofone
ormorecompletesetofchromosomes
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-69-35214116
A male human is heterozygous for autosomal genes A and B and is
also hemizygous for haemophilic gene h. What proportion of his
sperms will be abh?
(A)
(B)
(C)
(D)
CORRECTANSWER:A
SOLUTION:
1813211614
ThegenotypeofhumanmaleinquestionmustbeAaBb
.
Hence typesofgameteswouldbe
formed.AB ,ABY,aB
aBY,Ab ,AbY,ab ,abY.
Hence, proportionofhisspermswouldbeabh.
WatchVideoSolutionOnDoubtnutApp
Q-70-30701645
One barr body is found in man of genotype
(A)XY
(B)XXXY
(C)XXY
(D)XX
XhY
2 × 2 × 2 = 8
Xh Xh
Xh Xh
1/8
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-71-18705161
The point at which the polytene chromosomes appeart to be
attached togeher is known as
(A)Centriole
(B)Chromocentre
(C)Centromere
(D)Chromomere
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-72-35214182
Mental retardation in man, associated with sex chromosomal
abnormality is usually due to
(A)reductioninX-complement
(B)increaseinX-complement
(C)moderateincreaseinY-complement
(D)largeincreaseinY-complement
CORRECTANSWER:B
SOLUTION:
Sterilemaleswithundevelopedtestes,mental
retardation,etc.areduetoincreaseintheirX-
complementwhichtakesplaceinadisordercalled
Klinefelter'ssyndrome.Theseareformedbyunionofan
XXeggandanormalYspermornormalXeggand
abnormalXYsperm.Theindividualthushas47
chromosomes(44+XXY)
WatchVideoSolutionOnDoubtnutApp
Q-73-18705176
Balbiani rings are present in
(A)Polysomes
(B)Autosomes
(C)Polytenechromosomes
(D)Noneofthese
CORRECTANSWER:C
SOLUTION:
(c)PolytenechromosomeswasdescribedbyKollar
(1882)andfirstreportedbyBallbiani(1881).Theyare
foundinsalivaryglandsofinsects(Drosophila)and
calledassalivaryglandchromosomes.
WatchVideoSolutionOnDoubtnutApp
Q-74-18705211
Some genes in bacteria and virus mau bcode for more than one
polypetide, they are called in
(A)Overlappinggenes
(B)Jumpinggene
(C)Splitgene
(D)Noneofthese
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-75-35214132
Two crosses between the same pair of genotypes or phenotypes in
which the sources of the gametes are reversed in one cross, is
known as:
(A)dihybridcross
(B)reversecross
(C)testcross
(D)reciprocalcross
CORRECTANSWER:D
SOLUTION:
Sincegenotypes/phenotypesofbothparentsaresame-
onlysourcesofgametesarereversed,thesecrossesare
calledreciprocalcrosses.
WatchVideoSolutionOnDoubtnutApp
Q-76-18705214
"Cytochimeras" means
(A)Cellhavinghalodpid
(B)Cellshavingtwonuclei
(C)Cellshavingdifferentchromosomesotherthan
vegetativecells
(D)Noneofthese
CORRECTANSWER:C
SOLUTION:
(c)Chimerasaretheindividualhavingthedifferent
genotypesinitsdifferentparts.
WatchVideoSolutionOnDoubtnutApp
Q-77-35214162
Ratio of complementary genes is
(A)
(B)
(C)
(D)
CORRECTANSWER:D
SOLUTION:
Incaseofcomplementarygenes,theratioof9:7is
obtainedin -generation.Thiswasfirstdiscoveredby
BatesonandPunnett.
Complementarygenesarethosegeneswhichexpress
9 : 3 : 4
12 : 3: 1
9: 3: 3: 4
9: 7
F2
themselveswhenpresenttogether.Noneofexpress
themselveswhenpresenttogether.Noneofthesetwo
getexpressedyourselfwhenpresentalone.
WatchVideoSolutionOnDoubtnutApp
Q-78-35214123
In a mutational event, when adenine is replaced by guanine, it is the
case of
(A)frameshiftmutation
(B)transcription
(C)transition
(D)transversion
CORRECTANSWER:C
SOLUTION:
Incaseoftransition,purinebaseisreplacedbyanother
purine(e.g. )andpyrimidineisreplacedby
anotherpyrimidine(e.g. )andviceversa.In
caseoftransversionpurineisreplacedbyapyrimidine
andviceversa.
WatchVideoSolutionOnDoubtnutApp
Q-79-30701502
Cholchicine interferes in
(A)Spindleorganisation
(B)DNAreplication
(C)Chromosomecondensation
(D)Polyploidy
CORRECTANSWER:A
A ⇔ G
C ⇔ T
WatchVideoSolutionOnDoubtnutApp
Q-80-35214137
Which of the following discoveries resulted in a Nobel Prize
(A)Recombinationoflinkedgenes
(B)Geneticengineering
(C)X-raysinducesex-linkedrecessivelethalmutations
(D)Cytoplasmicinheritance
CORRECTANSWER:C
SOLUTION:
HJMullerwasawardedNobelPrizein1946forhis
discoveryoftheproductionofmutationbyX-ray
radiation.
WatchVideoSolutionOnDoubtnutApp
Q-81-30701546
Huntington 's chorea appears at the age of
(A)25-55years
(B)15-25years
(C)50-60years
(D)10-15years
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-82-35214118
The recessive genes located on X-chromosome in humans are
always
(A)lethal
(B)sublethal
(C)expressedinmales
(D)expressedinfemales
CORRECTANSWER:C
SOLUTION:
TherecessivegeneslocatedonX-chromosomein
humansarealwaysexpressedinmalesbecausea
femalemaybehomozygousorheterozygouswhilemale
isalwayshemizygous(i.e.onlyalleleispresent).
Haemophilia,colourblindnessaresomehuman
diseaseswhicharefrequentlyfoundinmales.
WatchVideoSolutionOnDoubtnutApp
Q-83-30701627
An auxotroph is a (an):
(A)Plantcapableofsynthesisingowncrbohydrates
(B)Plantshowingquickbendingresponsetosunlight
(C)Amutatnhavinglosttheabilitytosynthesisieoneor
morenutrients
(D)Anorganismdependentonanotherfornutritional
requirements
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-84-35214155
Inheritance would be extranuclear in case of
(A)KillerParamecium
(B)KillerAmoeba
(C)Euglena
(D)Hydra
CORRECTANSWER:A
SOLUTION:
Extranuclearinheritanceorcytoplasmicinheritanceis
theinheritanceofthecharactersofonlyoneparent
(generallythefemaleparent).E.g.somestrainsof
Parameciumcalledkillerstrain.
WatchVideoSolutionOnDoubtnutApp
Q-85-35214121
Lack of independent assortment of two genes A and B in fruit fly
Drosophila is due to
(A)repulsion
(B)recombination
(C)linkage
(D)crossingover
CORRECTANSWER:C
SOLUTION:
THMorgan(1910)explainedthelackofindependent
assortmentinDrosophiliaduetothelinkage.When
genescloselypresentadhereorlinktogetherinagroup
andtransmittedasasingleunit,thephenomenonis
calledlinkage.Itstopstheprocessofindependent
assortment.Incompletelinkageisbrokendowndueto
thecrossingover.
WatchVideoSolutionOnDoubtnutApp
Q-86-18705126
The largest gene in man is :
(A)Dystrophin
(B)Insulingene
(C)Betaglobingeneofhaemoglobin
(D)Tumorsuppressorgene
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-87-30701472
If a part of chromosome gets separted and reattached in reverse
positoion to the same chromosome, the mutation is called
(A)Inversion
(B)Transverion
(C)Transloction
(D)Genemutation
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-88-35214166
Mutation generally produces
(A)recessivegenes
(B)lethalgenes
(C)polygenes
(D)dominantgenes
CORRECTANSWER:A
SOLUTION:
Mutationsgenerallyproducerecessivegenes.Mutation
isasuddenheritablechangeinthecharacteristicsofan
organism.Theindividualwhichshowstheseheritable
changesisknownasmutant.
WatchVideoSolutionOnDoubtnutApp
Q-89-30701479
What term is appied to the gene mutation wher a base is replaced by
another base?
(A)Duplication
(B)Aneuploidy
(C)Euploidy
(D)Substitution
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-90-35214178
Albinism is known to be due to an autosomal recessive mutation.
The first child of a couple with normal skin pigmentation was an
albino. What is the probability that their second child will also be an
albino?
(A)
(B)
(C)
(D)
CORRECTANSWER:B
100 %
25 %
50 %
75 %
SOLUTION:
Since,albinismisarecessivecharacter,achildwillbe
albinoonlyifitishomozygousforalbinismgenes.Since,
parentshavenormalskin,itmeanstheyare
heterozygous.Asaresultofcrossbetweentwo
heterozygousparents25%ofthechildrenwillbe
homozygousrecessive.Thenatureofhtesecondchildis
notaffectedinanywaybythenatureofthefirstchild
becausebothareindependentevents.
WatchVideoSolutionOnDoubtnutApp
Q-91-30701506
The scientist who first discorved cytoplasmic inheritance was
(A)Correns
(B)Rhoades
(C)Mendel
(D)Morgan
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-92-18705142
Genes which are cofined to differential region of the Y-
chromosome only are called :
(A)Mutant
(B)Autosomal
(C)Holndric
(D)Completelysex-linked
CORRECTANSWER:C
SOLUTION:
(c)ThegenespresentonthedifferentialpartofY
chromosomearepasseddirectlyfromfathertosonand
arecalledasHolandricgenes.
WatchVideoSolutionOnDoubtnutApp
Q-93-35214164
During organ differentiation in Drosophila, an organ is modified to
another organ (such as wings may be replaced by legs). Genes
responsible for such metamorphosis are called
(A)doubledominantgenes
(B)plastidgenes
(C)complementarygenes
(D)homeoticgenes
CORRECTANSWER:D
SOLUTION:
Homeoticgenesarecontrolgeneswhicheitherbe
gettingexpressedorbyremainingsilentduring
development,influencethedifferentiationoforgans.
Thesehavebeenfoundininsectsnonenematodeand
someplants.ADNAsequencecalledhomeobox,
presentinthesegenes,isinvolvedinspecificationof
organs.
Amutationthatcausesabodyparttodevelopin
appropriatepositioninanorganism,iscalledhomeotic
mutation,e.g.inDrosophila,suchmutationmaycause
legstodevelopontheheadinplaceofantennae.
WatchVideoSolutionOnDoubtnutApp
Q-94-18705341
Mongoloid condition is releated to or In monglolism a patient
(A)Monosomy
(B)Trisomy
(C)Nullisomy
(D)Noneoftheabove
CORRECTANSWER:B
WatchVideoSolutionOnDoubtnutApp
Q-95-35214158
Male XX and female XY sometime occur due to :
(A)deletion
(B)transferofsegmentsinXandY-chromosomes
(C)aneuploidy
(D)hormonalimbalance
CORRECTANSWER:D
SOLUTION:
Hormondalinbalancemayleadtodevelopmentofmale
charactersinfemaleorviceversa.Deletionisthe
removalofoneoffewnitrogenousbasesfroma
nucleotidechain.Aneuploidyisachromosomal
aberrationinwhichcertainchromosomesarepresentin
extracopiesorcertainaredeficientinnumber.
WatchVideoSolutionOnDoubtnutApp
Q-96-18705219
Which of the following is incorrectly paired
(A)SrygeneXchromosome
(B)2n-2-nullisomic
(C)Nucleiodprokaryote
(D)Polytecnic
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-97-18705300
Example of qualilative inheritance is
(A)Colourofskin
(B)Colourblindness
(C)Klinefelter'ssyndrome
(D)Alkaptonuria
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-98-35214145
There are three genes a, b, c, percentage of crossing over between a
and b is 20%, b and c is 28% and a and c is 8%. What is the
sequence of genes on chromosome?
(A)b,a,c
(B)a,b,c
(C)a,c,b
(D)Noneofthese
CORRECTANSWER:A
SOLUTION:
Accordingtothegivenquestionthesequenceofgenes
sonchromosomeareb,a,c.
WatchVideoSolutionOnDoubtnutApp
Q-99-18705245
In slpit genes, the coding sequences are called
(A)Cistrons0
(B)Operons
(C)Exons
(D)Introns
CORRECTANSWER:C
SOLUTION:
(c)Unwantedportion(introns)ofgenesissplicedoff
andremainingparti.e.,exonsgetjoinedbyligase.
WatchVideoSolutionOnDoubtnutApp
Q-100-18705256
Which of the following is genetically dominant in man
(A)Colourblindness
(B)Rhpositive
(C)Haemophilia
(D)Albinism
CORRECTANSWER:B
SOLUTION:
(b)ThedifferencebetweenRhpositiveandRhnegative
dependonasinglepairofgenes(rr)withthegene
responsiblefortheRhpositiveconditiondominant(RR,
Rr)
WatchVideoSolutionOnDoubtnutApp
Q-101-35214127
Pattern baldness, moustanches and beard in human males are
examples of :
(A)sexdifferentiatingtraits
(B)sexdeterminingtraits
(C)sexlinkedtraits
(D)sexlimitedtraits
CORRECTANSWER:D
SOLUTION:
Sexlimitedtraitsarethosewhicharelimitedtoonesex
only.Moustaches,beardarefoundinhumanmalesonly.
Itwassuggestedonthebasisofstatisticalanalysisthat
prematurebaldnessiscontrolledbyadominantgene,
whichexpressesonlyinthepresenceofacertainlevel
ofmalehormone(androgen).
WatchVideoSolutionOnDoubtnutApp
Q-102-30701542
Phenylketonura is
(A)Sexlinkeddominanttrait
(B)Sexlinkedrecesivetrait
(C)Autosomaldominanttrait
(D)Autosomalrecessivetrait
CORRECTANSWER:D
WatchVideoSolutionOnDoubtnutApp
Q-103-18705162
Balbiani discovered special type of chronomus larva which are
recognized by the presence of
(A)Bands
(B)Loosps
(C)Bothbandsandloops
(D)Alltheabove
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-104-35214143
Genetic map is one that :
(A)showsthestagesduringthecelldivision
(B)showsthedistributionofvariousspeciesinaregion
(C)establishessitesofthegenesonachromosome
(D)establishesthevariousstagesingeneevolution
CORRECTANSWER:C
SOLUTION:
Geneticmapisadiagramwhichshowstherelative
positionofgenesonachromosome.Strutevantin1911
preparedthefirstgeneticmapoftwochromosomesof
fruitfly.
WatchVideoSolutionOnDoubtnutApp
Q-105-18705284
Rh factor is named after
(A)Man
(B)Rat
(C)Monkey
(D)Chimpanzee
CORRECTANSWER:C
SOLUTION:
Rhesusmonkey(Macaarhesus).
WatchVideoSolutionOnDoubtnutApp
Q-106-18705255
In human beings, the colour of skin is controlled by
(A)Multiplealleles
(B)Lethalgens
(C)Polytgeniceffect
(D)Noneofthese
CORRECTANSWER:A
SOLUTION:
(a)Theskincolourofapersonistheresultofan
interactionbetweentwopairsofgenes.
WatchVideoSolutionOnDoubtnutApp
Q-107-18705166
Lampbrush chromosomes are visible
(A)Indiploteneofmeiosis
(B)Inprophaseofmeiosis
(C)Ininterphase
(D)Inmetaphaseofmeiosis
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-108-35214139
In Drosophila, the sex is determined by
(A)theratioofpairsofX-chromosomestothepairsof
autosomes
(B)whethertheeggisfertilisedordevelops
parthenogenetically
(C)theratioofnumberofX-chromosomestothesetof
autosomes
(D)XandY-chromosomes
CORRECTANSWER:A
SOLUTION:
CalvinBridgesdemonstratedthatinDrosophilia,thesex
isdeteminedbyratioofthenumberofX-chromosomes
tothesetsofautosomes.Accordingtogenicbalances
theoryofsex-determination,Y-chromosomeof
Drosophiliadoesnotimportantforthedeterminationof
sex.
WatchVideoSolutionOnDoubtnutApp
Q-109-30701564
Allsomees are the name of
(A)Sexchromosomes
(B)Swellingsonthechromosomes
(C)Chromosomesotherthantheoneswhichdetermine
sex
(D)Nucleolusorganisingregionsofchromosomes
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp
Q-110-35214156
Number of Barr bodies in XXXX female would be
(A)1
(B)2
(C)3
(D)4
CORRECTANSWER:C
SOLUTION:
ThenumberofBarrbodiesinXXXXfemaleare3.Barr
bodyisacondensedmassofchromatinfoundinthe
nucleiofplacentalmammalswhichcontainoneormore
X-chromosomes,sonamedafteritsdiscoversMurray
Barr.ThenumberofBarrbodiesisonelessthanthe
numberofX-chromosomespresent.
WatchVideoSolutionOnDoubtnutApp
Q-111-30701489
When chromosome sets are present in multiple of 'n', the condition
is termed
(A)Diploidy
(B)Haploidy
(C)Euploidy
(D)Aneuploid
CORRECTANSWER:C
WatchVideoSolutionOnDoubtnutApp
Q-112-35214140
Genes for cytoplasmic male sterility in plants are located in
(A)nucleargenome
(B)cytosol
(C)chloroplastgenome
(D)mitochondrialgenome
CORRECTANSWER:D
SOLUTION:
Mitochondriaareoriginatedfrompre-existing
mitochondri.Thesearesemi-autonomous,living
organellespresentinalleukaryoticcells.Thesecontain
DNA(mtDNA).Theavailableevidencesshowthatthe
geneslocatedinmtDNAcontrolthecytoplasmicmale
sterility.
WatchVideoSolutionOnDoubtnutApp
Q-113-18705189
The linkage map of X-chromosome of fruit fly has 66 units with
yellow body gene Y at one end and bobbed hair B gene at he other
end. The recombination frequency between these two genes Y and
B should be
(A)1
(B)0.66
(C)0.5
(D)0.055
CORRECTANSWER:B
SOLUTION:
(b)Theactualdistancebetweentwogenesissaidtobe
equivalenttothepercentageofcrossingoverbetween
thesegenesi.e .Crossingoverchancesbetween
yandbgenessuggestthatthesearetobeplacedon
thechromosomeatadistanceof66units.
WatchVideoSolutionOnDoubtnutApp
Q-114-18705362
Edward's syndrome, Patau's syndrome and Down's syndrome are
66 %
due to
(A)Mutationduetomalnutrition
(B)Changeinsexchromosomes
(C)Changeinautosomes
(D)Changeinbothsexchromosomesandautosomes
CORRECTANSWER:C
SOLUTION:
Thereisalargescalepossibilityofautosomal
aneuploidyinhumanbeings.
WatchVideoSolutionOnDoubtnutApp
Q-115-18705201
Polytene Chromosomes are formed by
(A)Endoreduplicationofchromosomes
(B)Somanticpairingofhomologolouschromosomes
(C)Somanticpairingofnon-homologouschromosomes
(D)Germinalpairingofnon-homologouschromosomes
CORRECTANSWER:A
WatchVideoSolutionOnDoubtnutApp