vce vet laboratory skills · 2019. 3. 19. · 11 2017 vet lab skills exam t b – continued t...

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

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.

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.


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.


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.


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.


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.


SECTION B – continued

Question 2 (7marks)Alaboratorytechnicianwearingappropriatepersonalprotectiveequipment(PPE)hastoperformcultureplatestreakingofanEscherichia colibrothonanumberofagarplates.

a. Listtwopiecesofessentialequipmentthatwillneedtobecollectedtocarryoutthisprocedure. 2marks

b. Givetwopiecesofinformationthatshouldbeincludedoneachagarplatelabeltoidentifythestreakedcultureplate. 2marks

c. Nameonetypeofspreadingtechniquethatcouldbeusedinthisprocedure. 1mark

d. Thelaboratorytechnicianisstreakingmultipleplates.

Describetwoimportantproceduralstepsthatthetechnicianwouldcarryoutbetweenthestreakingofindividualplates. 2marks



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



Question 4 (6marks)Thetwomostcommonmethodsusedtodecontaminateclinicalandbiologicalwasteareautoclavingandliquidchemicaltreatment.

a. Statetwoextremeenvironmentalconditionsthatarecreatedduringtheautoclavingprocess. 2marks

1.

2.

b. Giveanexampleofwastematerialthatmustgothroughanautoclavingdecontaminationprocedureinapathologylaboratorybeforeitsdisposal,indicatingthemethodused. 1mark

c. Listthreefactorsthatwillreducetheeffectivenessofdisinfectants. 3marks

1.

2.

3.



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

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

13 2017 VET LAB SKILLS EXAM


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



Question 8 (5marks)Whileperformingatwo-pointbuffercalibration,alaboratorytechniciannoticesthatpHreadingsaretakingalongertimetostabilise.

a. Oncetheyhaveadvisedthesupervisor,whattwochecksshouldthetechniciancarryout? 2marks

b. ThecalibrationbuffersthatthetechnicianusesforthepHmeterareusuallypH4.00andpH7.00ThetechnicianlaterneedstomeasureaseriesofsolutionsaroundpH9.

Wouldusingthesecalibrationbuffersbegoodpractice?Justifyyouranswer. 1mark

c. TheSOPforcalibratingthepHmeterhasthefollowinginstruction:‘Immersetheelectrodebulbintothecalibrationbuffer,notethebufferreadingandadjusttotherequiredvalue.’

WhatisonechangethatthetechniciancouldsuggesttotheirsupervisorthatwouldimprovetheSOP?Justifyyouranswer. 2marks



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



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



CONTINUES OVER PAGE


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



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


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

vce vet laboratory skills · 2019. 3. 19. · 11 2017 vet lab skills exam t b – continued t...

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