8810-6004 13 pages

N10/4/BIOLO/SPM/ENG/TZ0/XX

Tuesday 2 November 2010 (afternoon)

BiologyStandard levelPaPer 1

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.

45 minutes

©International Baccalaureate Organization 2010

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1.

2. Whatisthesequenceofstagesduringthecellcycle?

A. G1 S G2 mitosis cytokinesis

B. mitosis G1 G2 cytokinesis S

C. G1 G2 S mitosis cytokinesis

D. G1 G2 mitosis cytokinesis S

[Questionandimageremovedforcopyrightreasons]

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3. Thegraphbelowshowsthecorrelationbetweenthebiomassofamarineworm,Arenicola,andthepercentageoforganicnitrogeninthesandwhereitlives.

Biomass/gm–2

40

30

20

10

0.008 0.012 0.016 Percentageoforganicnitrogen

[ReproducedwithpermissionfromPJHayward"AnimalsofSandyShores"(1994)TheRichmondPublishingCo.Ltd.]

Whatstatementcanbemadefromthedata?

A. The increase in thebiomassof thewormisdue toan increase in thepercentageoforganicnitrogen.

B. There is no relationship between the biomass of the worm and the percentage of organicnitrogen.

C. The increase in the percentage of organic nitrogen is due to an increase in the biomass oftheworm.

D. Asthebiomassofthewormincreasessodoesthepercentageoforganicnitrogen.

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4. Whatisthedifferencebetweenthestructureofallprokaryotesandalleukaryotes?

Prokaryotes Eukaryotes

A. cellwall nocellwall

B. chloroplasts nochloroplasts

C. flagellum noflagellum

D. nucleoid nuclearenvelope

5. Whatdoesfacilitateddiffusionacrossacellmembranerequire?

A pore protein ATP A concentration gradient

A. yes no no

B. no no yes

C. yes no yes

D. no yes no

6. The graph below represents the amount ofDNAduring the cell cycle. Which part of the graphrepresentsmetaphase?

MassofDNA/pg

6

5

4

3

2

1

0

A.

B.

C.

D.

0 2 4 6 8 10 12 14 16 18 20 22 24 Time/h

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7. Whichdiagrambestillustratestheinteractionsbetweenwatermolecules?

A. H

O

H

O

HH

B.

H

O

O

HH

H

C.

H

O

H

H

H

O

D.

H

O

H

O

H

H

8. Whatchemicalreactionistakingplacewhenadipeptidebecomestwoaminoacids?

A. Condensation

B. Hydrolysis

C. Denaturation

D. Polymerization

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9. ThebaseratiosintheDNAandRNAforanonion(Allium cepa)aregivenbelow.

Bases A / % G / % C / % T / %

DNA 31.8 18.4 18.2 31.3

Bases A / % G / % C / % U / %

RNA 24.9 29.8 24.7 20.6

Whatisthereasonforthedifferencebetweenthesefigures?

A. DNAisonlyfoundinthenucleusbutRNAisfoundthroughoutthecell.

B. DNAismadeentirelyofdoublehelixbutRNAisnot.

C. InDNAbasesAandTarecomplementarybutinRNAbasesAandCarecomplementary.

D. RNAcomesinthreeformsbutDNAonlycomesinoneform.

10. Whichofthefollowingwillcauseanenzymetopermanentlyloseitsproperties?

I. Hydrolysis

II. Freezingto–20C°

III. Dissolvingitinwater

A. Ionly

B. IIonly

C. IandIIonly

D. IandIIIonly

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11. Whatislactaseusedfor?

A. Itisusedtomakesugar-freemilk.

B. Ithydrolyseslactosetoglucoseandfructose.

C. Itimprovesthedigestionofmilkbysomepeople.

D. Itdecreasestheacidityofthemilk.

12. Howcantherateofphotosynthesisofaplantbedirectlymeasured?

A. Bymeasuringtherateofoxygenproduced

B. Bymeasuringtherateofcarbondioxideproduced

C. Bymeasuringtherateofplantgrowth

D. Bymeasuringtherateoflightabsorbed

13. Whatdoesthenucleusofahumanlymphocytecontain?

A. Onlythegenestoproduceaspecificantigen

B. Onlythegenestoproducearangeofantibodies

C. Onlythegenesthatcontrolthegrowthanddevelopmentofalymphocyte

D. Thewholegeneticinformationforahuman

14. A cell in the testis of a male chimpanzee (Pan troglodytes) contains 48 chromosomes. It isabout to undergomeiosis. Howmanymolecules ofDNAwill be present in the nucleus of thespermcells justaftermeiosis?

A. 96

B. 48

C. 24

D. 12

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15. Whatischorionicvillussampling?

A. Samplingcellsfromtheplacenta

B. Samplingcellsfromthefetaldigestivesystem

C. Samplingfetalcellsfromtheamnioticfluid

D. Samplingstemcellsfromtheumbilicalcord

16. HowcanfragmentsofDNAbeseparated?

A. Usingpolymerasechainreaction(PCR)

B. Usinggelelectrophoresis

C. Usinggenetransfer

D. Usinggenecloning

17. Toproduceartificialerythrocytesforuseinbloodtransfusions,tobaccoplantshavebeengeneticallymodifiedtoproducehumanhemoglobin.Thefirstthreetripletsofthehumanhemoglobingeneare:

ATGGTGCAT

What would be the first three triplets of the hemoglobin gene inserted into the genome of themodified tobaccoplants?

A. TACGTGGTA

B. ATGGTGCAT

C. TACCACGTA

D. GCAACATGC

18. WhycanDNAprofilingbeusedtodeterminepaternity?

A. Genesofchildrenareexactlythesameastheirfather’s.

B. Halfthegenesofchildrenarethesameastheirfather’s.

C. Thefatherpassesonallofhisgenestoeachofhischildren.

D. Thefatherpassesonafractionofhisgenesequaltothenumberofhischildren.

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Questions 19 and 20 refer to the food web shown below.

bobcat

roadrunner

weaselgophersnake

opossum

quail

deermouse

chaparralplants

kangaroorat

meadowmouse

19. Whatisthetrophiclevelofthebobcatinthefoodwebabove?

A. Primaryandsecondarylevelconsumer

B. Secondaryandtertiarylevelconsumer

C. Tertiaryandquaternarylevelconsumer

D. Secondaryandquaternarylevelconsumer

20. Whatistheenergytransferlevelfromthekangaroorattotheweaselshowninthefoodwebabove?

A. Threetimesgreaterthantheenergytransferfromtheroadrunnertothebobcat

B. Halftheenergytransferfromchaparralplantstothemeadowmouse

C. Aquarteroftheenergytransferfromthequailtothebobcat

D. Approximatelythesameastheenergytransferfromthemeadowmousetotheopossum

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21. Whichofthefollowingwillpromotevariationinaspecies?

I. Meiosis

II. Fertilization

III. Naturalselection

A. Ionly

B. IIonly

C. IandIIonly

D. I,IIandIII

22. Whyhasantibioticresistanceevolvedinbacteria?

A. Allbacteriareproduceveryquickly.

B. Bacteriaexposedtoantibioticsdevelopedaresistancetothem.

C. Varietiesofbacteriaresistanttoantibioticsreproducefasterthannon-resistantvarieties.

D. Bacteriashowingresistancetoantibioticssurviveafterantibioticsareused.

23. WhatfeaturesdistinguishPlatyhelminthesfromAnnelida?

Platyhelminthes Annelida

A. segmentedbody non-segmentedbody

B. non-segmentedbody segmentedbody

C. bilateralsymmetry nobilateralsymmetry

D. nobilateralsymmetry bilateralsymmetry

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24. Whatistrueofthesource,productsandoptimumpHofthelipasefoundinthehumandigestivesystem?

Source Products Optimum pH

A. salivaryglands fattyacids 8

B. stomach starch 2

C. pancreas fattyacids 8

D. liver aminoacids 2

25. Whichchamberofthehearthasthethickestwalls?

A. Leftatrium

B. Rightatrium

C. Leftventricle

D. Rightventricle

26. Whatcausesairtobebreathedoutbythelungs?

A. Thediaphragmrelaxesandtheribsfall.

B. Theribsriseandtheexternalintercostalmusclesrelax.

C. Theinternalintercostalmusclescontractandtheribsrise.

D. Thediaphragmcontractsandinternalintercostalmusclescontract.

27. Whatcausestheformationofanerveimpulseonthepost-synapticmembrane?

A. Ca2+bindingwithareceptorsite

B. K+leakingintothepost-synapticmembrane

C. Neurotransmitterbindingwithreceptorsites

D. Neurotransmitterbeingremovedfromthesynapse

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28. WhatisthedifferencebetweentheoriginoftypeIandtypeIIdiabetes?

Type I Type II

A. causedbyanautoimmunereaction targetcellsfailtorespondtoinsulin

B. occursinadultsonly startsinchildhood

C. toomuchinsulinsecreted toolittleinsulinsecreted

D. causedbydietaryproblems causedbyhereditaryfactors

29. Thefollowingdiagramshowsthehumanfemalereproductivesystemasseenfromtheside.

I

II

[DiagramadaptedfromHumanReproductiveBiology,3rded,Jones&Lopez,AcademicPress,p.52.CopyrightElsevierLtd2006,usedwithpermission.]

WhatarethenamesoftheorganslabelledIandII?

I II

A. uterus vagina

B. bladder ovary

C. urethra oviduct

D. clitoris cervix

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30. ThehormonesprogesteroneandLHweremeasuredinawoman’sbloodover40days. Whendidhermenstrualbleedstart?

Key: progesterone LH

Progesterone/pgcm–3LH/ngcm–3

35

30

25

20

15

10

5

0

A. B. C. D.

0 5 10 15 20 25 30 35 40 Time/days