vce vet laboratory skills - victorian curriculum · pdf fileversion 3 – february 2017 3...

S A M P L EVCE VET LABORATORY SKILLS

Written examination

Day Date Reading time: *.** to *.** (15 minutes) Writing time: *.** to *.** (1 hour 30 minutes)

QUESTION AND ANSWER BOOK

Structure of bookSection Number of

questionsNumber of questions

to be answeredNumber of

marks

A B

20 12

20 12

2080

Total 100

• Studentsarepermittedtobringintotheexaminationroom:pens,pencils,highlighters,erasers,sharpeners,rulersandonescientificcalculator.

• StudentsareNOTpermittedtobringintotheexaminationroom:blanksheetsofpaperand/orcorrectionfluid/tape.

Materials supplied• Questionandanswerbookof16pages• Answersheetformultiple-choicequestions

Instructions• Writeyourstudent numberinthespaceprovidedaboveonthispage.• Checkthatyournameandstudent numberasprintedonyouranswersheetformultiple-choice

questionsarecorrect,andsignyournameinthespaceprovidedtoverifythis.• AllwrittenresponsesmustbeinEnglish.

At the end of the examination• Placetheanswersheetformultiple-choicequestionsinsidethefrontcoverofthisbook.

Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.

©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2012Version3–February2017

SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education Year

STUDENT NUMBER

Letter

VETLABSKILLS(SAMPLE) 2 Version3–February2017

SECTION A – continued

Question 1AstreakplateisusedtoA. maintainculturesforlongperiods.B. countthenumberofbacterialcells.C. ensurethebacteriaarespreadevenly.D. isolatesinglecoloniesforidentification.

Question 2Inatitration,aburetteisusedtoA. accuratelyaddtheindicator.B. accuratelyaddthestandardreagent.C. measurethemassoftheunknownsample.D. measuretheconcentrationoftheunknownsample.

Question 3Whichoneofthefollowingisanexampleofasystematicerror?A. measuringeitherthetoporthebottomofthemeniscusB. ignoringasmallamountofasamplethathasbeenspiltonthebenchC. usingtwodifferentwatchestotakemeasurementtimesinachemicalexperimentD. usinganincorrectlycalibrateddigitalthermometertomeasurethetemperatureofanincubator

Question 4Tofocusalightmicroscopeathighmagnification(400×)A. usethecoarseadjustment,thenthefinefocus.B. openalldiaphragmstoallowmorelightintothelens.C. makesuretheobjectivelensisascloseaspossibletotheslide.D. focusatlowermagnificationbeforeattemptingtofocusathighermagnification.

Question 5AcolonyonanagarplateisaA. groupofbacterialcellsthatappearsimilar.B. groupofidenticalbacterialcellsthatformaclump.C. mixedgroupofbacterialcellsthataregrowingtogether.D. groupofbacterialcellsthatarederivedfromasingleoriginalcell.

SECTION A – Multiple-choice questions

Instructions for Section AAnswerallquestionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrectforthequestion.Acorrectanswerscores1;anincorrectanswerscores0.Markswillnotbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.

Version3–February2017 3 VETLABSKILLS(SAMPLE)

SECTION A – continuedTURN OVER

Question 6To prepare a standard solution of sodium carbonate, what glassware should be used?A. measuring cylinder, dropper pipette and beakerB. volumetricpipette,smallfunnelandconicalflaskC. volumetricflask,smallfunnelanddropperpipetteD. measuringcylinder,dropperpipetteandconicalflask

Question 7Disinfection is a process used by laboratory workers toA. handle microbes safely. B. clean laboratory work areas.C. reduce the number of pathogenic microbes on surfaces.D. remove all bacteria from glassware and instruments before use.

Question 8How many grams of NaCl would be required to prepare 200 mL of 5% (w/v) sodium chloride solution?A. 5B. 10C. 15D. 20

Question 9The production of waste is a problem for all laboratories.The amount of waste produced will increase ifA. spillages are kept to a minimum.B. standard operating procedures (SOP) are followed.C. poor quality materials that produce unreliable results are used.D. the correct quantity of chemicals is used when undertaking a process.

Question 10Abuffersolutionispreparedaccordingtothemethodspecifiedbythelaboratory’sSOPmanual.Which one of the following tests would be helpful in determining that the solution is suitable for use?A. Measure the pH of the solution.B. Titrate against a standard solution.C. Incubate a sample of the solution at 36 °C overnight.D. Heat a sample of the solution to determine its boiling point.

Question 11ResolutioncanbedefinedasA. how large a specimen appears.B. how clear and sharp a specimen appears.C. the distance between the objective lens and the slide.D. the relationship between the cone of light and the size of the lens.


SECTION A – continued

Question 12AprimarystandardisA. asubstancedissolvedinaknownvolumeofwater.B. themassofasubstancedissolvedinaknownvolumeofwater.C. asubstancethatisreactedwithasubstancewhoseconcentrationisknownaccurately.D. apuresubstancethatcanbeusedtodeterminetheconcentrationofothersubstances.

Question 13Alaboratorywantstoemploystaffwhoarefocusedonresponsibilityandaccuracy.Whichoneofthefollowingwouldbemostconsistentwiththisobjective?A. maintaininganattitudeof‘rightfirsttime’B. sharinginformationwithfriendsandcolleaguesC. changingSOPinordertoaccelerateresulttimesD. workingindependentlyandlimitingcommunicationwithothermembersoftheteam

Question 14Whichoneofthefollowingisanexampleofagoodaseptictechnique?A. openingallcontainersbeforecommencingworkB. workinginafumecupboardtoavoidtoxicfumesC. flamingthelidsofPetridishesafterstreakingaplateD. sterilisingallequipmentbeforecarryingoutaprocedure

Question 15Achemicalthathasa‘dangerousgoods’classificationA. canbestoredanywhereinthelaboratory.B. issafetouseinmostlaboratorysituations.C. canbeimmediatelydangeroustoapersonortheenvironment.D. canbehazardoustoaperson’shealthoveralongperiodoftime.

Question 16Beforediscardingwastescontainingspore-formingbacteria,thewastesshouldbeA. treatedwith0.01%hypochloritesolution.B. treatedwith80%ethanolforseveralminutes.C. exposedtoultravioletlightinabiosafetycabinet.D. autoclavedatthecorrecttemperatureandpressurefortherequiredtime.

Question 17Whichfeatureofamicroscopeenablestheusertoswitchfromoneobjectivetoanotherwithoutalteringthefocus?A. bifocallensB. parfocallensC. multifocallensD. astigmatism


END OF SECTION ATURN OVER

Question 18FlamingisatechniqueusedtoA. cleaninstrumentsafteruse.B. steriliseglasswarebeforeuse.C. removeinoculumfromaloop.D. cleanhandsafterworkingwithbacteria.

Question 19Achemicalhasbeenspiltonthefloorofalaboratory.Whatisthefirstactionthatshouldbetaken?A. Reportthespilltothesupervisorastheywillknowwhattodo.B. Wipeupthespillimmediatelywithapapertowelanddiscardthepapertowelinthebin.C. Alertotherstaffintheareaandreadthematerialsafetydatasheet(MSDS)beforecleaningupthespill.D. Spreaddisinfectantonthespillandleaveitfor20minutesbeforewipingitupwithapapertoweland

discardingthepapertowelinabiohazardouswastebin.

Question 20ThedecolourisingstepintheGramstaintechniqueisusedtoA. adjustthepHofthestaintomakeitadirectstain.B. preservethecells’structureandadherecellstotheslide.C. maintainosmoticpressureinasolutiontopreventcelllysis.D. breakdownacellwalltoallowthecounterstaintopenetratethecellwall.


SECTION B – Question 1–continued

Question 1 (9marks)Johasrecentlycommencedworkasalaboratorytechnicianinthequalitycontroldepartmentofalargepharmaceuticalcompany.Aspartofhercompanyinductionprogram,Joisaskedtobecomefamiliarwiththequalitymanual.

a. ListthreedocumentsJowouldfindinthequalitymanual. 3marks

1.

2.

3.

Aspartofherduties,Joisrequiredtocalibratethethermometersthatareusedtomonitorthetemperatureofincubatorsinthemicrobiologylaboratory.

b. i. WhydoesJoneedtocalibratethethermometers? 1mark

ii. DescribehowJowouldcalibratethethermometers. 1mark

iii. WhereshouldJorecordtheresultsofhercalibrationwork? 1mark

SECTION B – Short-answer questions

Instructions for Section BAnswerall questionsinthespacesprovided.


SECTION B – continuedTURN OVER

c. Inadditiontocheckingthetemperatureoftheincubatorsonadailybasis,Jomustgraphthedatacollected.

Herdailyrecordingsforthe36°Cor2°Cincubatorreadingsareshownbelow.

Day 1 2 3 4 5 6 7 8 9 10

Temperature (°C) 36.0 36.6 36.4 37.0 36.5 37.5 39.0 39.4 38.0 38.5

i. Prepareatrendgraphofthedataontheaxesprovidedbelow. 2marks

ii. Whatcouldbeaddedtothegraphtomakenon-conformancesmorereadilyidentified? 1mark


SECTION B – continued

Question 2 (7marks)Aqualitysystemmustincludestepstowardscontinuousimprovementandrequirethat non-conformancesbeidentifiedandactedupon.

a. Definetheterm‘non-conformance’. 1mark

b. Describetwowaysinwhichnon-conformancemaybedetected. 2marks

c. Describethebenefitsofcontinuousimprovementinlaboratorypractice. 4marks



Question 3 (9marks)Maree,thelaboratorytechnicianinameat-processingplant,takes10smallpiecesofmeatfromeachbatchofsausagesproduced,pureestheminablenderwithasterilebuffersolutionandthentransfersa1mLsampleasepticallyontosterileagarplates.

a. Listthethreeessentialcomponentsoftheplatemediathatwillallowbacteriatogrow. 3marks

1.

2.

3.

b. Mareehaspreparedtheplatecountmediafromadriedpowdermix.

Brieflydescribewhatsheshoulddotosterilisethemediaandmaintainthesterilityofthepouredplates. 2marks

c. WhattestswouldMareeneedtoundertakeaspartofthemediapreparationproceduretoensurethatthemediaissuitableforuse? 2marks

d. DescribethestepsthatMareeshouldtakeifthemediaisfoundtobeunsuitableforuse. 2marks



Question 4 (4marks)Somebacterialculturesareconsideredhazardousandcancauseseriousillness.

Listfourwaystoreducetherisktoatechnicianwhentheyhandlebacterialcultures.

1.

2.

3.

4.



Question 5 (7marks)Peterfollowsastandardoperatingprocedure(SOP)tocountthenumberofbacteriainawatersample.Hecommencesbymakingserialdilutionsofthewaterinsterilebuffereddiluents,adding1mLofeachdilutiontoa9mLsterileagardeep,thenmixingandpouringthemixtureintoasterilePetridish.Eachsampleistestedinduplicate.Tenfolddilutionsareused,startingwithundilutedwaterandendingatadilutionof1:1000.Anegativecontrolisalsoincluded,whichispreparedbyadding1mLofbuffereddiluenttoa9mLsterileagardeep.

a. NamethreepiecesofequipmentthatPeterwouldneedtoselectbeforehecommencestheprocedure. 3marks

1.

2.

3.

b. HowcouldPetermaintainthesterilityofthebuffereddiluents? 1mark

c. NametwoessentialitemsoflabellingthatwouldberequiredoneachPetridish. 2marks

1.

2.

d. Whatisthefunctionofthenegativecontrol? 1mark


SECTION B – Question 6–continued

Question 6 (10marks)Awater-testinglaboratoryusesananalyticalproceduretodeterminethelevelofcopperindrinkingwater.Thetestrequiresaseriesofcopperstandardsolutionstobepreparedandtheabsorbanceismeasuredattheoptimumwavelengthof580nmonacalibratedvisiblespectrophotometer.Topreparethestandardsolutions,thetechnicianplacescoppermetalina250mLbeakertowhich 20mLof5Mnitricacid,HNO3,isadded.Thisisheatedgentlyuntilthecopperisfullydissolvedandthen50mLofdeionisedwaterisadded.Thesolutionisstirred,cooledandtransferredintoa1Lvolumetricflask;deionisedwaterisaddedandmadeuptothe1Lmark.Thisstocksolutionisthendilutedtomakeupthevariousconcentrationsoftheotherstandardsolutions.

a. Listtwosafetymeasuresthatshouldbetakenwhendissolvingthecopperinthenitricacidsolution. 2marks

1.

2.

b. Ifthestocksolutionneedstohaveaconcentrationof0.2mg/mL,whatmassofcopper,ingrams,isrequiredtobedissolvedtopreparethe1Lofstocksolution?Showyourcalculations. 2marks

c. Theresultsofthemeasurementoftheabsorbanceofthecopperstandardsinavisiblespectrophotometerareshowninthefollowingtable.

Copper concentration (mg/mL) Absorbance

0.000 0.000

0.004 0.110

0.010 0.301

0.020 0.600

Plotthegraphofabsorbance(A)versusconcentrationofcopper(Conc)ontheaxesprovidedbelow. 3marks


SECTION B – Question 7–continuedTURN OVER

d. Thetechnicianthentestsawatersamplefromareservoirandtheabsorbancereadingis0.350

Whatistheconcentrationofcopperinthesample? 1mark

e. Whatistheconcentrationofnitricacidinthe1Lcopperstandardflask?Showyourcalculations. 2marks

Question 7 (9marks)A25mLaliquotofvinegar(whichcontainsaceticacid,CH3COOH)wasanalysedbytitrationwithstandardised0.110Msodiumhydroxide,NaOH.Threedropsofphenolphthaleinwereaddedtothevinegarbeforeitwastitrated.Anaveragetitreof18.35mLwasrequiredtoreachtheendpoint.

a. Whywasphenolphthaleinaddedtothevinegar? 1mark

b. Definetheterm‘equivalencepoint’. 1mark

c. Listthreepiecesofequipmentneededtoperformthisanalysis. 3marks

1.

2.

3.

d. Explainwhyanaveragetitreisusedintitrations. 1mark



e. Theequationforthereactionis

CH3COOH+NaOH→H2O+CH3COONa

Themolarmassofaceticacidis60.00g/mol.

Calculatethemass,ingrams,ofaceticacidinthe25mLsampleofvinegar.Showyourworking. 3marks

Question 8 (4marks)Atechnicianinaquality-testinglaboratoryistestingfoodsamplesandisrequiredtocheckthepHofabuffersolution.

a. Whatismeantbytheterm‘buffer’? 1mark

b. ThepHofthebuffersolutionwasmeasuredat5.6,butitshouldbeneutral.

ExplainhowthetechnicianwouldchangethepHofthesolutionsothatitisneutral. 2marks

c. Afteradjustingthebuffersolution’spH,thetechniciannoticesawhitefluffyprecipitateinthebufferstockbottle.

Whatactionshouldthetechniciantake? 1mark

Question 9 (2marks)Listtwothingsatechnicianwouldneedtocheckinordertoensurethechemicalsinastorageroomaresuitableforuse.

1.

2.



Question 10 (12marks)Themicrobiologytechnicianinateachinglaboratoryhasbeenaskedtopreparesomedemonstrationslidesofbacterialculturesforstudentstoexamineinapracticalclass.

a. Namethestainingtechniquethatwouldbemostsuitableforthispurpose. 1mark

b. Whatmustbedonetoasmearbeforeitisstainedandwhyisthisrequired? 2marks

c. Describethestepsusedinthestainingtechnique. 5marks

d. Whattypeofmicroscopeandmagnificationwouldbebestforthistask?Giveonereasonforyouranswer. 2marks

e. Describetwopossibleresultsofthestainingtechniqueused. 2marks


Question 11 (3marks)Aslideisbeingexaminedunderamicroscopeandablackmarkisnoticedinthefieldofview.Theblackmarkdoesnotmovewhentheslideismovedupordown,leftorright.

a. Whatisthemostlikelyexplanationforthisobservation? 1mark

b. Howwouldthisproblembecorrected? 2marks

Question 12 (4marks)Atechnicianinahaematologylaboratoryhasbeenaskedtoperformamanualcountofredbloodcells(RBC)inasampletakenfromapatient.

a. Inadditiontoabrightfieldmicroscope,whatpieceofspecialisedequipmentwouldthetechnicianneedtoperformthecount? 1mark

b. Nameoneoccupationalhealthandsafetyfeatureoftheworkstationthatthetechnicianneedstoensureiscorrectbeforecommencingthecountingprocedure. 1mark

c. Asampleofbloodiscountedandtheresultisrecordedas5.25×108RBC/µL.

Howmanyredbloodcellswouldtherebeinalitreofbloodfromthispatient?Showyourcalculations. 1mark

d. Afterperformingthecount,howshouldthetechniciancleantheequipmentused? 1mark

END OF QUESTION AND ANSWER BOOK

VET LAB SKILLS (SAMPLE – ANSWERS)

© VCAA 2012 – Version 3 – February 2017

Answers to multiple-choice questions

Question Answer

1 D

2 B

3 C

4 D

5 D

6 C

7 C

8 B

9 C

10 A

11 B

12 D

13 D

14 D

15 C

16 A

17 A

18 B

19 C

20 D

vce vet laboratory skills - victorian curriculum · pdf fileversion 3 – february 2017 3...

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