vce vet laboratory skills€¦ · vet lab skills (sample) 4 version 3 – february 2017 section a...
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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.
VETLABSKILLS(SAMPLE) 4 Version3–February2017
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
Version3–February2017 5 VETLABSKILLS(SAMPLE)
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.
VETLABSKILLS(SAMPLE) 6 Version3–February2017
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.
Version3–February2017 7 VETLABSKILLS(SAMPLE)
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
VETLABSKILLS(SAMPLE) 8 Version3–February2017
SECTION B – continued
Question 2 (7marks)Aqualitysystemmustincludestepstowardscontinuousimprovementandrequirethat non-conformancesbeidentifiedandactedupon.
a. Definetheterm‘non-conformance’. 1mark
b. Describetwowaysinwhichnon-conformancemaybedetected. 2marks
c. Describethebenefitsofcontinuousimprovementinlaboratorypractice. 4marks
Version3–February2017 9 VETLABSKILLS(SAMPLE)
SECTION B – continuedTURN OVER
Question 3 (9marks)Maree,thelaboratorytechnicianinameat-processingplant,takes10smallpiecesofmeatfromeachbatchofsausagesproduced,pureestheminablenderwithasterilebuffersolutionandthentransfersa1mLsampleasepticallyontosterileagarplates.
a. Listthethreeessentialcomponentsoftheplatemediathatwillallowbacteriatogrow. 3marks
1.
2.
3.
b. Mareehaspreparedtheplatecountmediafromadriedpowdermix.
Brieflydescribewhatsheshoulddotosterilisethemediaandmaintainthesterilityofthepouredplates. 2marks
c. WhattestswouldMareeneedtoundertakeaspartofthemediapreparationproceduretoensurethatthemediaissuitableforuse? 2marks
d. DescribethestepsthatMareeshouldtakeifthemediaisfoundtobeunsuitableforuse. 2marks
VETLABSKILLS(SAMPLE) 10 Version3–February2017
SECTION B – continued
Question 4 (4marks)Somebacterialculturesareconsideredhazardousandcancauseseriousillness.
Listfourwaystoreducetherisktoatechnicianwhentheyhandlebacterialcultures.
1.
2.
3.
4.
Version3–February2017 11 VETLABSKILLS(SAMPLE)
SECTION B – continuedTURN OVER
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
VETLABSKILLS(SAMPLE) 12 Version3–February2017
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
Version3–February2017 13 VETLABSKILLS(SAMPLE)
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
VETLABSKILLS(SAMPLE) 14 Version3–February2017
SECTION B – continued
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.
Version3–February2017 15 VETLABSKILLS(SAMPLE)
SECTION B – continuedTURN OVER
Question 10 (12marks)Themicrobiologytechnicianinateachinglaboratoryhasbeenaskedtopreparesomedemonstrationslidesofbacterialculturesforstudentstoexamineinapracticalclass.
a. Namethestainingtechniquethatwouldbemostsuitableforthispurpose. 1mark
b. Whatmustbedonetoasmearbeforeitisstainedandwhyisthisrequired? 2marks
c. Describethestepsusedinthestainingtechnique. 5marks
d. Whattypeofmicroscopeandmagnificationwouldbebestforthistask?Giveonereasonforyouranswer. 2marks
e. Describetwopossibleresultsofthestainingtechniqueused. 2marks
VETLABSKILLS(SAMPLE) 16 Version3–February2017
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