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VCE VET LABORATORY SKILLSWritten examination
Wednesday 22 November 2017 Reading time: 9.00 am to 9.15 am (15 minutes) Writing time: 9.15 am to 10.45 am (1 hour 30 minutes)
QUESTION AND ANSWER BOOK
Structure of bookSection Number of
questionsNumber of questions
to be answeredNumber of
marks
A 20 20 20B 14 14 80
Total 100
• Studentsarepermittedtobringintotheexaminationroom:pens,pencils,highlighters,erasers,sharpeners,rulersandonescientificcalculator.
• StudentsareNOTpermittedtobringintotheexaminationroom:blanksheetsofpaperand/orcorrectionfluid/tape.
Materials supplied• Questionandanswerbookof20pages• 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.
©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2017
SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education 2017
STUDENT NUMBER
Letter
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2017VETLABSKILLSEXAM 2
SECTION A – continued
Question 1Whichoneofthefollowingshouldbeusedtocleanadustylightmicroscopelens?A. lenspaperB. wetpapertowelC. disposablefacialtissueD. softcleanclothwith70%ethanolsolution
Question 2ContinuousoutcomeimprovementinalaboratoryworkplaceisimportantbecauseA. itkeepsstaffbusyandfocused.B. itprovidesincentivesfornewstaff.C. clientsonlywantthelatestversionofproductsandservices.D. itcreatesopportunitiestobecomemoreprofitableandcompetitive.
Question 3AnexampleofcontinuousimprovementinsustainabilityinalaboratoryworkplacewouldbeA. decreasingtheamountofsolventused.B. shorteninglunchbreakssostaffcanincreasetheiroutput.C. prioritisingreducingthenumberofcalibrationprocedures.D. alwaysdisposingofequipmentthatismorethanseveralyearsold.
SECTION A – Multiple-choice questions
Instructions for Section AAnswerallquestionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrectorthatbest answersthequestion.Acorrectanswerscores1;anincorrectanswerscores0.Markswillnotbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.
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3 2017VETLABSKILLSEXAM
SECTION A – continuedTURN OVER
Question 4
19
20
21
The volume of liquid indicated on the burette above is closest toA. 19.80 mLB. 19.90 mLC. 20.10 mLD. 20.20 mL
Question 5Which one of the following pathways for chemicals entering the body is eliminated by the use of a fume cupboard?A. absorptionB. inhalationC. ingestionD. injection
Question 6The correct place to label bottles and tubes used as containers of media is on theA. lid of the container.B. side of the container.C. bottom of the container.D. lid and bottom of the container.
Question 7An experienced laboratory technician has invited an inexperienced technician to learn a laboratory technique. How should the inexperienced technician respond?A. Refuse the invitation so they do not annoy their supervisor.B. Suggest they discuss this with their supervisor before proceeding.C. Accept the invitation and work through their lunchbreak to complete other tasks.D. Accept the invitation and hope the experienced technician will be too busy later.
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2017VETLABSKILLSEXAM 4
SECTION A – continued
Question 8AnexampleofanoperatorerrorwouldbeA. incorrectsamplingpreparationtechnique.B. useofareagentthatcontainsanimpurity.C. poortechniquewhenperformingatitration.D. selectingequipmentthathasanunstableelectricalsupply.
Question 9Whichoneofthefollowingisaquantitativedeliveryvessel?A. beakerB. bulbpipetteC. volumetricflaskD. measuringcylinder
Question 10Howmanymolesofhydrochloricacid,HCl,arein25.0mLof0.2MHCl?A. 0.005B. 0.5C. 50D. 125
Question 11Whenpreparingasepticsampletransfersofbacterialbroth,alaboratorytechnicianshouldA. freezeallsamplesuntilthetransfersneedtobeperformed.B. firstcheckthedatebywhichthecustomerrequirestheresults.C. performthetransfersquicklytoavoiddeteriorationofthesamples.D. firstcheckthatthesamplingprocedureconformswiththesamplingplan.
Question 12Whenflamingaloopforspreading,itisbestpracticetoA. useanorangeflame.B. workfromthehandleendtothewireloopend.C. workfromthewireloopendtothehandleend.D. workinanydirectionaslongastheflameisveryhot.
Question 13Aftercompletinganymicrobiologicalsamplingandtransferprocedure,localworkareasmustbecleanedwithA. 0.1%v/vhypochloritesolution.B. 10%v/vhypochloritesolution.C. 70–80%v/vethanol.D. 100%v/vethanol.
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5 2017VETLABSKILLSEXAM
SECTION A – continuedTURN OVER
Question 14Onwhichofthefollowingarechemicaldisinfectantsleasteffective?A. fungiB. prionsC. bacteriaD. microorganisms
Question 15Whichoneofthefollowingisthemostaccuratefield-of-viewsettingtooptimisetheresolutionofmountedslideimages?
B. C. D.A.
Question 16Whichlistofpipetteswouldprovidethemostaccurateresultswhenworkingwithdilutedbloodsamples?A. bulbpipette,PasteurpipetteandgraduatedpipetteB. bulbpipette,calibratedpipetteandPasteurpipetteC. bulbpipette,calibratedpipetteandgraduatedpipetteD. calibratedpipette,Pasteurpipetteandgraduatedpipette
Question 17Aprocedurerequiresthree1gsamplestobeweighed.Theactualweightsrecordedwereasfollows:• Sample1=0.8004g• Sample2=0.8009g• Sample3=0.7995g
TheweightsrecordedforthesesamplescouldbedescribedasA. accurateandprecise.B. accurate,butnotprecise.C. precise,butnotaccurate.D. neitheraccuratenorprecise.
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2017VETLABSKILLSEXAM 6
END OF SECTION A
Question 18Aserialdilutionisperformedintwosteps:• Step1–Usingabulbpipette,20mLofa2Mhydrochloricacid,HCl,stocksolutionistransferredintoa
100mLvolumetricflaskandmadeuptotherequiredmark.• Step2–20mLofthesolutionmadeinStep1isthentransferredintoanother100mLflaskandmadeup
totherequiredmark.
Whatisthefinalconcentrationofthesolutionaftertheserialdilutiondescribedinsteps1and2hasbeenperformed?A. 0.08MB. 0.2MC. 0.4MD. 0.8M
Question 19Whichoneofthefollowingisthecorrectdisposalprocedureforaliquidmicrobiologicalsample?A. Treatwithstrongdetergentbeforeflushingitdownasink.B. Autoclaveuntilsterile,thendisposeofwithspecialisttoxicwastecollectors.C. Autoclaveuntilsterile,thenflushitdownasinkaccordingtolocalregulations.D. Treatwith1%hypochloritesolution,dryautoclave,thenflushitdownasink.
Question 20ThecondenserinacompoundlightmicroscopeisusedtoA. focusthepathoflight.B. focusimagesonslides.C. provideadditionalcontrasttoimages.D. controlbrightnesstoreduceeyestrain.
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7 2017VETLABSKILLSEXAM
SECTION B – continuedTURN OVER
Question 1 (6marks)Shownbelowisadiagramofatechnician’spoorlysetupworkspace.
a. Onthediagramabove,identifythreeareasofpotentialstrainonthetechnician’sbodycausedbythepoorarrangementoftheworkspaceandequipment.Usethreelabelledarrowstoindicatetheareasofpotentialstrain. 3marks
b. Whatcouldthetechniciandotoavoideachofthethreeareasofpotentialstrainidentifiedinpart a.? 3marks
1.
2.
3.
SECTION B – Short-answer questions
Instructions for Section BAnswerall questionsinthespacesprovided.
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2017VETLABSKILLSEXAM 8
SECTION B – continued
Question 2 (7marks)Alaboratorytechnicianwearingappropriatepersonalprotectiveequipment(PPE)hastoperformcultureplatestreakingofanEscherichia colibrothonanumberofagarplates.
a. Listtwopiecesofessentialequipmentthatwillneedtobecollectedtocarryoutthisprocedure. 2marks
b. Givetwopiecesofinformationthatshouldbeincludedoneachagarplatelabeltoidentifythestreakedcultureplate. 2marks
c. Nameonetypeofspreadingtechniquethatcouldbeusedinthisprocedure. 1mark
d. Thelaboratorytechnicianisstreakingmultipleplates.
Describetwoimportantproceduralstepsthatthetechnicianwouldcarryoutbetweenthestreakingofindividualplates. 2marks
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9 2017VETLABSKILLSEXAM
SECTION B – continuedTURN OVER
Question 3 (7marks)Alaboratorytechnicianstartstosetuphiscompoundmicroscope,whichhasjustbeenremovedfromthestoragecupboard.Henoticesthattheoilimmersionlensisoverthestageandiswetwithoil,sohestartstocleanthelenswithopticaltissuemoistenedwithxylenesolvent,asstatedinthestandardoperatingprocedures(SOP).
a. Outlinetwofurtheractionsthetechnicianshouldtakeinthissituation. 2marks
b. Thesafetydatasheet(SDS)ofthexylenesolventstatesthatitisaflammable,hazardoussubstancethatisabsorbedthroughtheskinandrespiratorytract.(TheSDSwasformerlyknownasthematerialsafetydatasheetorMSDS.)
SuggesttwoitemsofappropriatePPEthatthetechnicianshouldwearwhenusingthexylenesolvent. 2marks
Thetechniciandisposesoftheusedopticaltissueinthewastepaperbin,whichisnormallycollectedbycontractcleaners.
c. Providetworeasonswhythisisnotarecommendedprocedure. 2marks
d. Suggesthowthetechnicianshouldhavesafelydisposedofthiswaste. 1mark
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2017VETLABSKILLSEXAM 10
SECTION B – continued
Question 4 (6marks)Thetwomostcommonmethodsusedtodecontaminateclinicalandbiologicalwasteareautoclavingandliquidchemicaltreatment.
a. Statetwoextremeenvironmentalconditionsthatarecreatedduringtheautoclavingprocess. 2marks
1.
2.
b. Giveanexampleofwastematerialthatmustgothroughanautoclavingdecontaminationprocedureinapathologylaboratorybeforeitsdisposal,indicatingthemethodused. 1mark
c. Listthreefactorsthatwillreducetheeffectivenessofdisinfectants. 3marks
1.
2.
3.
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11 2017VETLABSKILLSEXAM
SECTION B – continuedTURN OVER
Question 5 (7marks)Atechnicianinapathologylaboratoryhasbeengiven12bottlesofbacterialbroth,withsixoftheselabelledBordetella pertussisandtheothersixlabelledBacillus cereus.Thetechnicianneedstoconfirmthepurityofthetwobacterialcultures.AGramstaintestwasperformedonthestrainofcultureineachbottle.TheresultsareshowninTable1andTable2below.
Table 1. Bordetella pertussis Table 2. Bacillus cereus
Bottle number Gram stain result
Bottle number Gram stain result
1 –ve 1 +ve
2 –ve 2 +ve
3 +ve 3 +ve
4 –ve 4 +ve
5 –ve 5 +ve
6 +ve 6 +ve
a. WhatobjectiveandeyepiecelenswouldneedtobeusedtoperformtheGramstaintest? 2marks
Objective
Eyepiecelens
b. Whichtableofresultswouldraiseconcernsforthetechnician?Giveareasonforyouranswer. 2marks
c. Listtwoactionsthatwouldneedtobecarriedoutupongettingtheseresults. 2marks
d. Whatdisposalmethodshouldbeusedforthe12bottlesofbacterialbrothonceallworkhasbeencompleted? 1mark
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2017 VET LAB SKILLS EXAM 12
SECTION B – Question 6 – continued
Question 6 (7 marks)A white blood cell (WBC) count is conducted on a blood sample using a Neubauer chamber, or haemocytometer, and the SOP specifies using four of the large corner squares or grids. The blood sample was diluted 1:20 with acetic acid solution, then one side of the test chamber was filled with the mixture and the cells were counted. The results are shown on grids A to D below.
A B
C D
1 mm
a. Using grids A to D above:
i. count the WBC and record your readings in the table below 4 marks ii. calculate the total number of WBC counted and record your answer in the space
provided in the table below. 1 mark
Grid WBC
A
B
C
D
Total
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13 2017 VET LAB SKILLS EXAM
SECTION B – continuedTURN OVER
b. Calculate the WBC count per millilitre of the blood sample using the formula provided below. Show your working. 2 marks
cells/mL total number of cells 10 dilution factornumbe
=× ×4
rr of corner squares (grids)
dilution factor = 1:20
Question 7 (4 marks)A partly completed document used in a laboratory quality program is shown below. Program 1 has already been entered.
Program Input Process Output
1 blood serum SOP I: Preparation of albumin standard protein solution
laboratory test report
2
a. Using the entries provided below, fill in the input, process and output for Program 2 in the document above:• absorption reading• SOP II: Preparation of standard glucose solution• urine sample 1 mark
b. Suggest one other program that could be implemented to improve the laboratory’s services and its approach to dealing with customers. In your answer, use the terms ‘input’, ‘process’ and ‘output’, and explain your suggested program. 3 marks
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2017VETLABSKILLSEXAM 14
SECTION B – continued
Question 8 (5marks)Whileperformingatwo-pointbuffercalibration,alaboratorytechniciannoticesthatpHreadingsaretakingalongertimetostabilise.
a. Oncetheyhaveadvisedthesupervisor,whattwochecksshouldthetechniciancarryout? 2marks
b. ThecalibrationbuffersthatthetechnicianusesforthepHmeterareusuallypH4.00andpH7.00ThetechnicianlaterneedstomeasureaseriesofsolutionsaroundpH9.
Wouldusingthesecalibrationbuffersbegoodpractice?Justifyyouranswer. 1mark
c. TheSOPforcalibratingthepHmeterhasthefollowinginstruction:‘Immersetheelectrodebulbintothecalibrationbuffer,notethebufferreadingandadjusttotherequiredvalue.’
WhatisonechangethatthetechniciancouldsuggesttotheirsupervisorthatwouldimprovetheSOP?Justifyyouranswer. 2marks
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15 2017VETLABSKILLSEXAM
SECTION B – continuedTURN OVER
Question 9 (3marks)Errorsoccurwhenperforminganyscientificwork.Mostlaboratoryerrorscanbecategorisedasoneofthefollowingtypesoferrors:• operator• equipment• method
Foreachoftheerrorsrecordedbelow,indicatethetypeoferroritisbyticking()theappropriateboxinthetable.
Type of error
Error Operator Equipment Method
lossofasubstancewhentransferringmaterialsduringweighing
analyticalscaleisnotweighingaccurately
useofareagentthatispastitsuse-bydate
Question 10 (4marks)Apathologylaboratoryisrequiredtostoreitsspecimensbelow4°C.Currently,aroutinecheckisdoneat9.00ameachdaytorecordthelaboratoryrefrigerator’stemperatureandthisiswritteninamanuallog.
a. Suggesttworeasonswhythismethodmightbeinadequateasachecktoensurespecimensarestoredbelow4°C. 2marks
1.
2.
b. Provideabetteralternativetotheroutinecheckdescribedabovetoensurespecimensarestoredbelow4°C.Yourresponsemustconsiderthereasonssuggestedinpart a. 2marks
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2017VETLABSKILLSEXAM 16
SECTION B – continued
Question 11 (6marks)ConsiderthefollowingqualitycontrolgraphthathasbeenusedtomonitorthevitaminCconcentrationoforangejuiceproducedbyamanufacturingcompany.ThepackaginglabelstatesthattheconcentrationofvitaminCis45mg/100mL.
concentration
mean
Key
1 2 3 4 5 6 7 8
sample number (hourly interval)
Quality control graph for vitamin C concentration
9 10 11 12 13 14 15
39
40
41
42
43
44
45
46
47
concentrationof vitamin C
(mg/100 mL)
a. Referringtothegraphabove,whatisthemeanconcentrationofvitaminCintheorangejuice? 1mark
Thelowercontrollimit(LCL)is42mg/100mLandtheuppercontrollimit(UCL)is 47mg/100mL.
b. Drawandlabelalineonthegraphabovetorepresenteachoftheselimits. 2marks
c. Fromthegraph,identifythesamplenumbersthatwouldindicatepossiblesourcesoferrorandwhy. 2marks
d. Whichsamplenumberscouldindicateasystematicerror? 1mark
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17 2017VETLABSKILLSEXAM
SECTION B – continuedTURN OVER
CONTINUES OVER PAGE
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2017VETLABSKILLSEXAM 18
SECTION B – Question 12–continued
Question 12 (7marks)Atechnicianperformsatitrationtodeterminetheconcentrationofasolutionofsodiumhydroxide,NaOH,whichhasanapproximateconcentrationof0.1M.Thetechnicianuses25.00mLofahydrochloricacid,HCl,standardsolutionwithaknownconcentrationof0.1025M.ThefollowingvolumesofNaOHwereobtained.
Titre Volume of NaOH
1 24.65mL
2 24.65mL
3 24.55mL
4 24.60mL
5 24.80mL
a. Listthethreetitresthatarewithin0.1mLofeachother. 1mark
b. Calculatetheaveragetitrevolume. 1mark
c. Writeabalancedequationforthisacid-basereaction. 1mark
d. Thetechnicianusesa50mLburettewithascalethathasasmallestincrementof0.1mL.
i. Whatisthebasicmeasurementprincipleusedwhentakingreadingsfroma50mLburettewiththisscale? 1mark
ii. Howmanydecimalplacescouldbeaccuratelymeasuredwhenusingthisburette? 1mark
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19 2017VETLABSKILLSEXAM
SECTION B – continuedTURN OVER
e. Areadingof25.38mLwasalsorecordedforthetitrationdescribedonpage18.
Canthisreadingbeconsideredaccurate?Giveyourreasoning. 2marks
Question 13 (6marks)Atechnicianhasbeenaskedtoperformaserialdilutionusingthefollowingprocedure:• Step1–Pipette20mLof5Msodiumhydroxide,NaOH,stocksolutionintoa200mL
volumetricflasklabelledSolutionAandmakeuptothemark.• Step2–Pipette20mLofSolutionAintoa200mLvolumetricflasklabelledSolutionBand
makeuptothemark.• Step3–Pipette20mLofSolutionBintoa200mLvolumetricflasklabelledSolutionCand
makeuptothemark.
a. CalculatetheconcentrationsofsolutionsA,BandC. 3marks
b. Whatisthedilutionfactorineachstep? 1mark
c. Beforeperformingtheserialdilution,whatstepsshouldbetakentoensurethattheglasswareiscleanandfreeofcontaminants? 2marks
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2017VETLABSKILLSEXAM 20
Question 14 (5marks)Atechnicianhasbeenaskedtoprepareastandardsolutionofhydrochloricacid,HCl.
a. Thetechnicianusesanaqueoussolutionof36%concentratedHClthathasamolarityofapproximately11.6M.
Calculatethevolumeofstocksolutionrequired,inmillilitres,toprepare20Lof0.1MHCl.Showyourworking. 2marks
b. Doestheresultantstandardsolutionneedtobestandardisedbeforeuse?Giveyourreasoning. 1mark
c. AfterviewingtherelevantSDS,thetechnicianbecomesawarethatusingconcentratedHClhasthefollowingrisks:• causessevereskinburnsandeyedamage• causesrespiratoryirritation
Thelaboratoryhasahierarchyofhazardcontrol,asshownbelow.
Hierarchy of hazard controlelimination→ substitution→ engineeringcontrols→ administrativecontrols→ PPE
Chooseonehazardcontrolfromthehierarchyaboveanddescribethecontrolmeasuresthatshouldbeundertakenwithinthelaboratorytominimisetherisksassociatedwiththepreparationofthesolution. 2marks
Hazardcontrol
Controlmeasures
END OF QUESTION AND ANSWER BOOK
2017 VCE VET Laboratory SkillsSection A – Multiple-choice questionsSection B – Short-answer questions