BiologyHigher levelPaper 1

15 pages

Monday 14 May 2018 (afternoon)

1 hour

Instructions to candidates

• Do not open this examination paper until instructed to do so.• Answer all the questions.• For each question, choose the answer you consider to be the best and indicate your choice on

the answer sheet provided.• The maximum mark for this examination paper is [40 marks].

© International Baccalaureate Organization 2018

M18/4/BIOLO/HPM/ENG/TZ1/XX

2218 – 6007

1. Common pesticides used by gardeners contain neonicotinoids.

[Source: © International Baccalaureate Organization 2018]

Whatistheeffectofaneonicotinoidpesticideonthetransmissionofanerveimpulsebetweenneurons in an insect?

A. Itpreventsthereleaseofacetylcholinefromthepresynapticmembrane.

B. Itwidensthesynapticcleftsodiffusionofacetylcholineacrossthegapisslower.

C. Itirreversiblybindswithacetylcholinereceptorsonthepostsynapticmembrane.

D. Itinterfereswiththeenzymaticbreakdownofacetylcholinebyacetylcholinesterase.

2. Howdoespotassiummoveacrossthemembraneofaneuronduringrepolarization?

A. Simplediffusion

B. Facilitateddiffusion

C. Endocytosis

D. Activetransport

3. Whichorganelleprovidesevidencethateukaryoticcellsoriginatedwhenlargeprokaryotesengulfedsmallfree-livingprokaryotes?

A. Chloroplast

B. Nucleoid

C. 80S ribosome

D. Vacuole

M18/4/BIOLO/HPM/ENG/TZ1/XX– 2 –

4. Theconcentrationsofcyclinsriseandfallincellsatcertaintimes.

Cyclin D

Cyclin E Cyclin A Cyclin B

[Source:https://en.wikipedia.org/wiki/Cyclin#/media/File:Cyclin_Expression.svg]

What times are these?

A. Day and night

B. Seasonsoftheyear

C. Stagesofmitosisandinterphase

D. Developmentalstagesinthelifecycle

5. Whatfeatureofcarbonmakesitmostsuitableasabasisforlife?

A. Its abundance in nature

B. Its bonding properties

C. Itsreactivitytolight

D. ItspresenceintheearlyatmosphereoftheEarth

6. Howarefatsandcholesteroltransportedintheblood?

A. Asgroupsofmoleculesinsidevesicles

B. Asindividualmoleculescoatedinphospholipids

C. Asindividualmoleculesboundtoaprotein

D. Asgroupsofmoleculesinlipoproteincomplexes

Turn over

M18/4/BIOLO/HPM/ENG/TZ1/XX– 3 –

7. Whichfattyacidwouldoccurinatransfat?

A.

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[Source: © International Baccalaureate Organization 2018]

8. Whichproteinhasthehighesttensilestrength(abilitytoresistbreakingwhenstretched)?

A. Cellulose

B. Actin

C. Spidersilk

D. Albumin

9. WhatdoDNAreplication,transcriptionandtranslationhaveincommon?

A. Takeplaceincellnucleus

B. Requirefreenucleotides

C. Catalysed by polymerase

D. Complementary base pairing

M18/4/BIOLO/HPM/ENG/TZ1/XX– 4 –

10. Whatisalwayspassedtothenextgenerationasaresultofsexualreproduction?

A. Homologouschromosomesfromthemother

B. Achromatidfromeverychromosomeofthefather

C. Ahaploidsetofchromosomesfromthemother

D. Allallelesfromeachparent

11. Whendosplittingofcentromeres,randomassortmentofchromosomesorreductiondivisionofchromosomestakeplace?

A. Interphase and meiosis I

B. Meiosis I only

C. Meiosis I and meiosis II

D. Meiosis II only

12. WhichgenotypewouldbeseeninapersonsufferingfromHuntington’sdisease?

A. Hh

B. hh

C. XHY

D. XhY

13. Forwhatpurposearerestrictionendonucleasesusedinthelaboratory?

A. TolimitthelengthofDNAmoleculesinthenucleus

B. TocutspecificbasesequencestoopenDNAmolecules

C. TopreventreleaseofDNAfromthenucleus

D. ToprotectviralDNAfromdigestionbybacterialenzymes

Turn over

M18/4/BIOLO/HPM/ENG/TZ1/XX– 5 –

14. Thethree-toedsloth,Bradypus variegatus,livesintreetopswhereitfeedsonleaves.Italsofeedsonalgaeandfungiwhichliveinitsfur.

[Source:Imagefromhttps://commons.wikimedia.org/wiki/File:Bradypus_variegatus.jpg.ChristianMehlführer. LicensedunderCCby2.5https://creativecommons.org/licenses/by/2.5/deed.en]

Inwhichtrophicgroupshouldthethree-toedslothbeclassified?

A. Autotroph

B. Consumer

C. Detritivore

D. Saprotroph

15. Animalsinthehighesttrophiclevelofafoodchainwilloftenbethelargestinbodysizebutwillbefewinnumbers.Whataccountsforthesmallnumbers?

A. Foodeatenbyanimalsatthehighesttrophiclevelhasalowerenergycontentpergram

B. Energylossesthroughthefoodchain

C. Conversionofheatenergyintochemicalenergy

D. Biomassofproducersissmall

16. Whichconditionsfavourpeatformation?

A. Dry Aerobic Acidic

B. Wet Anaerobic Acidic

C. Dry Anaerobic Basic

D. Wet Aerobic Acidic

M18/4/BIOLO/HPM/ENG/TZ1/XX– 6 –

17. Balkangreenlizards,Lacerta trilineata,livinginmainlandGreeceeatmostlyinsectsbutalsosmallamountsofplants.ThesamespecieslivingonGreekislands(whereinsectsarescarce)showagreaterpercentageofthosephysicaltraitsusefulforeatingplantsthanthemainlandlizards.

[Source:PennyTurner/WikimediafilelicensedunderCCBY-SA4.0https://creativecommons.org/licenses/by-sa/4.0/deed.en]

Whatisthebiologicalexplanationfortheseobservations?

A. Variationineachlizardpopulationallowedadaptationtooccur.

B. Lizardsmigratedtoareaswheretheywerebetteradapted.

C. Lizardsontheislandsdivergedduetolackofinterbreedingwiththemainlandpopulation.

D. Homologousstructureshavepreventedseparatespeciesfromevolving.

18. Whichphylumshowsradialsymmetry?

A. Annelida

B. Cnidaria

C. Platyhelmintha

D. Porifera

Turn over

M18/4/BIOLO/HPM/ENG/TZ1/XX– 7 –

19. ThecladogramwasconstructedusingDNAbasesequencesfromsixspecies.Whichnodeindicatesthegreatestdifferenceinbasesequences?

Species I

Species II

Species III

Species IV

Species V

Species VI

C.B.

A.

D.

[Source: © International Baccalaureate Organization 2018]

20. Bacteriafromchickenfecescancausealossofintestinalvilliinsmallchildrenwhohappentoeatdirtinruralvillages.Whicheffectcouldbeexpectedfromsuchalossofvilli?

A. Insufficientabsorptionofstarch

B. Failuretodigestdietaryfibre

C. Malnutrition

D. Anincreaseinmicrovilli

21. Whenintensephysicalactivityisanticipated,whichfactorinthebloodwillincreasethefrequencyofsinoatrialsignalstoheartmuscle?

A. pH

B. Oxygenlevel

C. Thyroxin

D. Epinephrine

M18/4/BIOLO/HPM/ENG/TZ1/XX– 8 –

22. Mucustrapspathogenicbacteria.Mucusalsoattractsvirusesthatattackpathogenicbacteria.

Virus particles

[Source: EYE OF SCIENCE/SCIENCE PHOTO LIBRARY]

Whatpartoftheimmunesystemdothesevirusesresembleintheirfunction?

A. Antigens

B. Antibodies

C. Memory cells

D. Antibiotics

23. Howaretheinsidesofalveolipreventedfromstickingtogether?

Method of prevention Produced by

A. Surfactant Type I pneumocytes

B. Surfactant Type II pneumocytes

C. Pressure MixtureofO2 and CO2withinalveoli

D. Pressure CO2 concentration gradient inside capillaries

Turn over

M18/4/BIOLO/HPM/ENG/TZ1/XX– 9 –

24. Neuralpathwaysinlivingbrainscannowbemappedbytrackingthemovementofwatermoleculesinsideaxons.Whatkeepswatermoleculesinsideaxons?

A. Plasma membrane

B. Hydrogen bonding

C. Pump proteins

D. Synapse

25. What releases leptin?

A. Thyroid gland

B. Hypothalamus

C. Pineal gland

D. Adipose tissue

26. WhichinformationaboutDNAstructurewasdeducedfromtheX-raydiffractionpatternsobtainedbyRosalindFranklin?

A. Presenceofpurinesandpyrimidines

B. Helical shape

C. Antiparallel strand arrangement

D. Deoxyribosebackbone

27. WhatdoeseukaryoticDNAhavethatismissingfromprokaryoticDNA?

A. Uracil

B. Promoter DNA

C. Introns

D. Coding sequences

M18/4/BIOLO/HPM/ENG/TZ1/XX– 10 –

28. What are polysomes?

A. Stringsofaminoacids

B. PackagesofeighthistoneswithDNA

C. ManyribosomesjoinedtoonemRNA

D. ComplexesoftRNAwithaminoacids

29. Isoleucinewillinhibitthereactionpathwayshownbelowwhentheconcentrationofisoleucineexceedsthecellrequirements.

threonine intermediate I intermediate II intermediate III intermediate IV isoleucineE1 E2 E3 E4 E5

Which enzyme does isoleucine inhibit?

A. Enzyme E1

B. Enzyme E2

C. Enzyme E3

D. Enzyme E5

30. WhathappenswhenpyruvateisconvertedtoacetylCoAinthelinkreaction?

A. Decarboxylation

B. Phosphorylation

C. Hydrolysis

D. Reductionofpyruvate

31. ATPisneededtochangeproductsofthecarboxylationofribulosebisphosphateinto triose phosphate. What other substance is also needed?

A. Rubisco

B. NADP

C. NAD

D. Reduced NADP

Turn over

M18/4/BIOLO/HPM/ENG/TZ1/XX– 11 –

32. Howdowatermoleculesenterrootcells?

A. Transpiration

B. Tension

C. Capillary action

D. Osmosis

33. Inaplant,whattissue(s)is/arespeciallyadaptedtotransportsucrose?

Cortex Phloem Xylem

A.

B.

C.

D.

34. Fruit-eatingbatslivinginprotectedBrazilianrainforestsareattractedoutoftheforeststoflyoveradjacentclearedland.Whichphaseofplantlifecouldthebatsbeassisting?

A. Germination

B. Flowering

C. Pollination

D. Seed dispersal

35. Whatformswhentwodifferentchromatidsofthesamehomologouspaircrossover?

A. Daughter centromere

B. Chiasma

C. Chromosome mutation

D. Telomere

M18/4/BIOLO/HPM/ENG/TZ1/XX– 12 –

36. Whatcouldaccountforthisdistributionofheightinapopulation?

120 140 160 180 200 220

Height / cm

HeightofNorthAmericanmen

Freq

uenc

y

[Source:GraphadaptedfromSixMinuteshttp://sixminutes.dlugan.com/good-public-speaker-average/]

A. Genelinkage

B. Dominant alleles

C. Independent assortment

D. Multiple genes

Turn over

M18/4/BIOLO/HPM/ENG/TZ1/XX– 13 –

37. AvaccineagainstmeningitisA,adeadlybacterialdisease,haseradicatedthediseasein16Africancountriessince2010.However,meningitisAstillexistsinthosecountrieswherepeopleareunvaccinated.

Whatarethepossibleaimsofepidemiologicalresearchsuchasthis?

Test vaccine effectiveness

Identify distribution of disease

Identify cause of disease

A.

B.

C.

D.

Removedforcopyrightreasons

M18/4/BIOLO/HPM/ENG/TZ1/XX– 14 –

38. Whatmovementoccursattheelbowandwhatisthestateofthetricepswhenliftinganappletotakeabitefromit?

Movement of the elbow

State of the triceps

A. extension relaxed

B. flexion contracting

C. extension contracting

D. flexion relaxed

39. Thepresenceofproteinssuchasalbumininaurinesampleindicateskidneydamage.Whereinthekidneywouldthedamageexist?

A. Renal artery

B. Cortex

C. Medulla

D. Pelvis

40. WhatcontributestothetotalDNAcontentofazygote?

Sperm EggNucleus Mitochondria Nucleus Mitochondria

A.

B.

C.

D.

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