support 24/7
Subscribe!
Home » essay examples » 55392598

55392598

Biology

Lab#1 IntroductiontotheMicroscopy, ObservationofProkaryoticandEukaryotic Cellular material Introduction Manyofthecellsandorganismsthatyouwillbestudyingareatthelowerlimitsofvisibilityoflightmicroscopes, therefore , itisextremelyimportantthatyouattaincriticallightinganddirecting. Itisalsoimportanttohandlethemicroscopecompetentlytoavoiddamagingeitherthemicroscopeorthepreparationyouarestudying. Evenstudentswhohavepreviouslyusedmicroscopesshouldreadtheinstructionscarefully.

GuideBiolabo By using a web rowser, go tothefollowingwebweb page: http://salinella. bio. uottawa. ca/biolabo/(youcantryitfromhome). UnderMicroscopyyouwillfindlinkstopagesthatdescribebothtypeofmicroscopesyouwillusethissemester, aswellashowtosetupandusethese people. Itisstronglyrecommendedthatyouvisitthesepagespriortoattendingyourfirstlab. ImageJ/Qcapture Althoughyoucanmakeallyourobservationsbywatchingdirectlythroughtheoculars, italsocanbedoneonthecomputerscreenusingthedigitalcameraattachedtoeachmicroscopic lense.

Forthat, youwillusetheImageJprogramtogetherwithacaptureplugin calledQcapture. VisitthelabwebsitetolearnhowtouseImageJ(linkonthehomepage). Allobservationscanbemadeonyourcomputerscreenorintheoculars. Eachmethodhasitsadvantagesanddrawbacks, youwillhavetochoosewhichoneitmoreappropriate(ortheoneyouprefer): Oculars Screen? Greaterresolution? Widerfieldofview? Canshareobservationwithothers? Morecomfortableforusers? Takepictureswhileobserving Lab1 Microscopy TheCompoundMicroscope OntheGuideBiolabopageclickontheCX41CompoundMicroscopelinkthenonPartsandFunction. Thiswillbringupalabelledlinediagramofyourmicroscope. Familiarizeyourselfwiththevariouscomponentsshowninthisfigure. After that, clickonSetupandBrightfieldalignmentinordertoknowhowtouseandhandlethemicroscope. Now, locateyourcompoundmicroscopeinthecupboardbelowthesinkofyourworkstation. Placeitonthecounterbetweenthe omputerandtheendofthecounter. Besurethatwheneveryoutransportthemicroscope, itisalwayskepterect, theocularlenswillfalloutifthescopeistiltedorthrown. Eventhoughyoudon’tneedthedissectingmicroscoperighttoday, takeitoutofthecupboardandinstallitbesidethecompoundmicroscope. Connectonefirewirecabletoeachofthecamerasinstalledontopofthemicroscopes. Thisway, everythingissetupforfurtherobservationsbothonyourcomputerscreenandthroughtheoculars. Partsofthecompoundmicroscope

Themicroscopeconsistsofasystemoflenses, alightsource, andagearedmechanismforadjustingthedistancebetweenthelenssystemandobjectbeingseen. Thereareanumberofimportantcomponentsanditisessentialthatyoubeabletoidentifythemandunderstandtheirfunctionbeforeyoucanproceed. BygoingthroughthedifferentmodulesinBiolaboandusingthemicroscopeyouwilldevelopacompetencyforbrightfieldmicroscopy. IdentifythefollowingcomponentsusingBiolabo(Partsandfunctionsfigure)andyourmicroscope:

REVOLVINGNOSEPIECE: Supportsthevariousobjectives Youwillonlyusethe4x, 10xand40xobjectivesintheBIO1140labs(notthe100x). STAGE: Supportsthespecimenbeingobserved. AsystemofknobsonthesideofthestageallowsyoutomovethespecimenundertheobjectiveontheXandYaxes. Tryandmovethestage. COARSEFOCUSCONTROL: Permitsrapidchangeindistancebetweenthespecimenandtheobjectivetherebyallowingforroughfocussing”Donotusewhenfocusingwiththe40xobjective

FINEFOCUSBUTTON: Permitssmallchangesindistancebetweenthespecimenandtheobjectiveandtherebyallowsforfinalfocussingoftheimage. 15 Lab1 Microscopy OCULAROREYEPIECE: Amagnifyingelementinthemicroscopic lense, usually10X. Itisthroughtheocular, oreyepiecethatonelooksatthespecimen. Allourmicroscopesareparfocal, sothatwhenanobjectisinfocuswithoneobjective, thefocuswillnotbecompletelylostwhenchangingtothenextobjective. AIMS: Themagnifyingelementwhichisclosesttothespecimen.

Seefigure1tofindoutabouttheengravingsonthesideofeachobjective. CONDENSER: Systemoflensesthatconcentratesthelightfurnishedbytheilluminator. Itdoesnotmagnifytheobject. CONDENSERHEIGHTADJUSTMENTKNOB: Allowsonetofocustheconcentratedlightontothespecimen. APERTUREIRISDIAPHRAGM: Usedtoreduceglarefromunwantedlightbyadjustingtheangleoftheconeoflightthatcomesfromthecondenser, ProductionofImagebyaCompoundMicroscope Themostimportantpartofamicroscopeisthetarget.

Alltheotherpartsoftheinstrumentaredesignedtohelptheobjectiveproducethebestpossibleimage. Thebestimageisnotthelargest, itistheclearest. Thereisnovaluetoahighmagnifying. Iftheresolutionispooryouwillhavenobetterunderstandingofthespecimen. lightbeam ocularlens Magnification Numericalaperture(NA) Determinestheresolving poweroftheobjective* Opticaltubelength/max. coverslipthicknessinmm prism objectivelens specimen condenserlens Figure1: Objectivesengravings lightsource

Figure2: Imageproductioninacompoundmicroscope. 14 Lab1 Microscopy *Resolvingpoweristheabilitytoseetwoobjectsthatareverycloseastwoseparateobjects. Thehumaneyewillresolvingpowerisabout100m. Usingthecompoundmicroscope AlwayshandlethemicroscopeGENTLY! Itisanexpensive, delicateandheavytool. Carryitwithtwohands, onehandonthearm, andtheotherhandunderthebase. Iftheocularorobjectiveisdirty, wipeitcleanusingONLYKimwipesorspeciallenstissueandcleaningfluidsupplied.

Ifyouuseanythingelseyoumayscratchthelens. Wipeupanycleaningfluidimmediately, otherwiseitwilldissolvethegluewhichholdsthelensinplace. REMEMBER, yourdemonstratorisheretohelp, so, INQUIRE! 1 . Makesurethatthepowercordispluggedintothebackofyourmicroscopeandintoapoweroutlet. 2 . Usingtheletter”emicroscopeslideprovided, followsteps2through13intheSetupandBrightfieldalignmentprocedureofBiolabo. Remember, observationcanbedoneonscreenorthroughtheoculars. Orientationandworkingdistance. Startingyourexaminationwiththe4Xobjective, positiontheletter”e”slideonthestage. 2 . Drawwhatyouseeinthemicroscope: _________________ 3. Whatwouldaslidewiththeletter”tlooklikeunderthemicroscope? _________________ 4. Usingtheknobslocatedonthesideofthestageandlookingthroughthemicroscopic lense, movetheslideslowlytotheright, thentotheleft. Recordyourobservations. ___________________________________5. Today, movetheslideslowlyawayfromyou, thentowardsyouwhileobservingthroughthemicroscope.

Recordyourobservations____________________________________ 6. Focusontheslideat10X. Checkthedistancebetweentheobjectivelensandyourslide(=theworkingdistance, seealsothereferenceattheendofthischapter). Nowswitchtothe40Xobjectiveandchecktheworkingdistance. Whathappenstotheworkingdistanceasyourmagnificationimproves? 12 Lab1 Microscopy Depthoffield(depthoffocus) Lenseshaveadepthoffocus. Itisthenumberofplanesinwhichanobjectappearstobeinfocus.

Extendyourfistatarm’slengthinfrontofyouandholdyourthumbup. Concentrateonyourthumbandnoticethattheobjectspastyourthumbontheothersideoftheroomarenotclearlyseen. Similarlywithamicroscope, whenitisfocussedononesurface, thesurfaceslowerorhigherwillbeoutoffocus. 1 . Positionapreparedslidewithcolouredthreadsuponthestage. Atlowelectrical power, 4X, focusontheareawherethethreadscross. 2 . Usingthefinefocusadjustment, focusupanddownslowly. 3. Repeatusingdifferentaims.

Whatcanyousayaboutthedepthoffieldatdifferentmagnifications? Hasitincreasedordecreased? (i. e., canyouseemorethreadsinonefocalplaneat4Xor40X? ) ____________________________________________________________ Magnification Themagnificationgivenbyobjectivesandocularsisengravedonthem. Thetotalmagnificationforanycombinationofobjectiveandocularistheproductofthemagnificationofeachlens. Objectivemagnification Ocularmagnification TotalMagnification Lightintensity Workingdistance 4x 10x 40x Large 22mm 10x 10x 100x

Medium 15. 5mm 40x 10x 400x Low zero. 56mm Table1 Comparisonzoom, workingdistanceandbrightnessatthreedifferentobjectivemagnifications. Youalsocancalculatethemagnificationofyourpictureusingthefollowingformula: Magnificationfactor=measuredsizeofobject=(X) Actualsizeofobject 13 Lab1 Microscopy SpecimensizeandMagnificationof thepicture Beforeyoustartthisexercise, makesureyouhavecarefullyreadthewebsitesectionrelevanttothesoftwareyouwillusetotakedigitalpictures(ImageJ/Qcapture).

Thegoalofthissectionistoteachyoudifferenttechniquesthatwillallowyoutodeterminethesizeofobjectsyou’reobservingunderthemicroscopic lense. Thegeneralprincipleisfairlybasic: 2objectshavethesamerelativesize(expressedasaratio)intherealworldandunderthemicroscopic lense. actualsizeofobjectA=on? screensizeofobjectA A1=A2actualsizeofobjectBon? screensizeofobjectBB1B2 Thefollowingexercisesareapplicationsofthisformula. Placeaslideunderthemicroscope.

Choosetherightobjectiveandadjustthefocusandlightlevel. In that case, chooseastructureyouwanttomeasureandtakeapicture. A? Firsttechnique: Measuringanobjectusingthefieldofview(FOV): Thesimplestwaytodeterminethesizeofanobjectistousetheknownsizeofthewholefieldofview(FOV, thewholepicturefromlefttoright). 1? Onthecomputerscreen(usingarulerandwithoutwritinganythingofthescreen), measuretheobjectofwhichyouwanttodeterminethesize(=A2) 2? Then, measurethewidthofthewholepictureonthescreen(=B2).? Refertotable2onpage20toknowtheactualsizeofthefieldofviewfortheobjectiveyou’reusing(=B1) 5? Usethefollowingformula: Actualsizeoftheobject(A1)=ActualsizeoftheFOV(B1)xon? screensizeoftheobject(A2) in? screensizeoftheFOV(B2) Case: Onasnapshotusingthe4xobjective, aninsecthasanabout? screenlengthof10cm. Thewholepictureis20cmwide. Whatistheactualsizeoftheinsect? ______________________________ 18 Lab1 Microscopy B? Secondmethod: Measuringanobjectusingascalebarfile:

FromImageJ(usingthefile/opencommand), openthefilethatcontainstherelevantscalebarinthe(T: /BIO/BIO1140): new10X. jpgforthe10xobjective, andnew40X. jpg(forthe4xand40xobjectives). In that case, usingarulermeasurethefollowingdistancesdirectlyonthecomputerscreen: 1? Theon? screenlength(orwidth)oftheobjectwhosesizeyouwishtodetermine(=A2) 2? Thewidthofthescalebaronthescreen(=B2)Younowcancalculatetheactualsizeoftheobjectusingtheformula: actualsizeofobject=on? creenlengthofobjectxactualsizeofscalebar*on? screenlengthofscalebar? A1=A2xB1 B2 *Theactualsizeofthescalebarisindicatedonthescalebarfile(ex: onthenew10x. jpgfile, thebarrepresents0. 2mmat10xor0. 02mmat100x)=B1 Example: Itookapictureofasmallinsectlarva, usingthe4xobjective. Thelarvalengthis60mmonthescreen. Thescalebaronthenew40x. jpgis30mmandrepresents0. 2mm. Whatistheactualsizeofthelarva? _________________________

Donotputthecompoundmicroscopebackinthecupboardyouwillneeditlaterthisafternoon. Pointstorememberconcerningmicroscopes 1 . Alwaysworkwithacleanmicroscope. Useonlythelenspaperprovided. Don’tforgettocleantheslidetoo! 2 . Alwayslocatethespecimenunderlowpowerandworkyourwayuptothehighpowerobjective. several. Neverusethecoarsefocusingknobwhenthehighpowerlensisinlocation. Useonlythefinefocusknob. four. Neverusethe100xin1styearlabs(wedidn’tteachyouhow)5.

Alwaysreadjustilluminationwheneveryouchangethegoal. Toomuchlightwillgiveyouablurryimagethatyoucannotfocuson. 15 Lab1 Microscopy Thestereoscopicmicroscope (dissectingmicroscope) Thestereoscopicmicroscope, alsocalledstereoscopeordissectingmicroscope, isusedtoviewobjectsthataretoolargeortoothicktoobserveunderthecompoundmicroscope. Stereomicroscopesarealwaysequippedwithtwoocularsproducingastereoscopicorthree? dimensionalimage. Unlikethecompoundmicroscope, theimageisnotinverted.

Ourstereomicroscopesprovidemagnificationintherangeof6. 7X 45Xusingazoom? typelensprogram. Byrotatingadiallocatedontherightsideofthestereomicroscopemind, theviewerobtainsacontinuouschangeofmagnification. Ourstereomicroscopescanbeusedwithreflectedortransmittedlumination. Reflectedlightisdirecteduntoopaquespecimensfromaboveandisreflectedtotheviewer. Transmittedlightisusedwithtranslucentspecimensandpassesthroughthespecimenfrombeneaththestageandintotheviewer’seyes.

Useofthestereoscopicmicroscope 1 . OntheBiolabohomepageleftclickonStereoscope(Dissectingmicroscope)andthenonStereoscopesetup. 2 . ClickonStep1andreaditcarefully. Obtainastereomicroscopefromthesamecupboardasyourcompoundmicroscopeifyouhaven’tyet. 3. Clickonandreadsteps2through7. 4. Placeacoinonthestage. 5. Usingthefocussingknoboneithersideofthearm, lowerorraisetheobjectiveuntilthecoinisinfocus. Examineitinbothreflectedandtransmittedlight.

Whichisbestforanopaquespecimen? Trythevariousmagnificationsbyturningthezoombutton. Thereflectedlight sourceissimilartoaspotlightanditsorientationcanbeadjustedmanually. Tryrotatingthelightupwardsanddownwards. 6. Examineothermaterialssuchasbrineshrimplarvae(Artemia)inawatchglassusingbothreflectedandtransmittedlight. Add1? 2dropsof”proto? slowsolutiontoslowdownthelarvae. Estimatetheactualsizeofonelarva: __________ 16 Lab1 Microscopy ProkaryoticandEukaryoticcells

Ithaslongbeenrecognizedthatlivingorganismsarecomposedofbasicstructuralandfunctionalunitscalledcellular material. Cellscanbedividedintotwogeneraltypes: prokaryoticandeukaryotic, basedonthepresenceofanucleusandothermembraneboundorganellesinthelatter. Prokaryoticcellsbelongto2biggroups: archaeaandeubacteria. Theyareusuallysmallerthaneukaryoticcells(typically1? 5m). Theseunicellularorganismsmaybesmall, buttheyarethemostabundantorganismsontheentire world, representingabouthalfthebiomass(Biology, Brookeretal. 010, McGraw? Hill, Ryerson). Theyaredevoidofmembraneboundorganellesuchasthenucleus, mitochondriaorchloroplasts. Theirgeneticmaterialisusuallycomposedofonecircularchromosomeplusotherextrachromosomalelementscalledplasmids. Eukaryoticcellsareusuallymuchlarger. Theypossessamembraneboundnucleus, theirorganellesaremorecomplexandnumerous, andtheirgenomeislargerthanprokaryotes. Eukaryoticorganismscanbeuni? ormulticellular. Youwillhaveachancetoobservemanyeukaryoticcellsduringthissemester: Amoeba, Lilly, Whitefish¦.

Intoday’sexerciseyouwilltakeafirstlookatthesimilaritiesanddifferencesbetweenprokaryoticandeukaryoticcellsaswellasthediversitywithinthesegroups. Youshouldfamiliarizeyourselveswithawholearrayofcellularstructuresandorganellesyouwillprobablyencounterduringthecourseofthisexercise. Beforeyourscheduledlabsession, writedownthedefinitionandfunctionforeachofthefollowingterms: plasma(cell)membrane, cellwall, protoplast, cytoplasm, vacuoles, nucleus, nucleolusandchloroplasts.

EukaryoticCells: Elodea(plant) one particular? GetayounggreenElodealeaffromthejar. Mountitinadropofwateronacleanmicroscopeslidewiththeconvexsideoftheleafuppermost. Coverthepreparationwithacoverslip. 2? Observethepreparationat4X, thenat10X. Ifyouseebrownishovalstructuresontheleafsurface area, ignorethen. Theseareprobablyepiphyticdiatoms. Concentrateyourattentiononthecellsnearthecentralribatthebaseoftheleafandonthemarginalcellsattheedgeoftheleaf. Canyoudistinguishseverallayersmakinguptheleaf? ____? Whatistheaveragelength______andwidth______ofthecellsinmicrometres? 17 Lab1 Microscopy several? Focussingat40Xlocatethecellwall, thevacuole, thecytoplasmandthenumerousgreenchloroplasts.? Whatimportantbiologicalprocesstakesplaceinthechloroplasts? _____________________________________? Whatpigmentisresponsiblefortheirgreencolouration? ________________________________________________? Whatistheshapeofchloroplasts? ____________________________________________? Arethechloroplastsmoving? Whatsortofmovement? _________________________________________________? Thephenomenonyouareobservingiscalledcytoplasmicstreamingorcyclosis. Whatdoyouthinkthefunctionofsuchaprocesscouldalways be? ___________________________________________________ 4? Youhaveprobablyrealisedthattheplasmamembranecannotbeseeninplantcells. Itistoothintoberesolvedwiththecompoundmicroscope.

Inordertoseethetruelimitingboundaryofthecytoplasmitisnecessarytotreatthecellsinsuchamannerthattheplasmamembranebecomeswithdrawnawayfromtherigidcellwall. Thiscanbedonebyplacingthecellinastrongsaltsolution. Thiswillcausewatertodiffuseoutofthecellbyosmosis, therebydecreasingthecellamount. Theunaffectedcellwall membrane remainsinitsoriginalstate. Whatcanthenbeseenisaspacebetweenthecellwallandthelimitingboundaryoftheprotoplast(thecellminusthecellwall)whichtherebybecomesvisible. RemoveyourElodeaslidefromthemicroscopestage. Delicatelyremovethecoverslip, addonedropof5%NaClsolutionthenputbackthecoversliponyourpreparation? Refocusat40x(don’tignore: youmustfirstfocusat4X, then10Xandfinallyat40x).? Arethecellsplasmolyzed? (Ifnotwaitawhilelonger). Howdotheylooklikenow? ______________________? Hasthecellwallbeenaffected? _________________ Whatbecomesofthelargecentralvacuoleduringplasmolysis? _____________________________________________________ TakeapictureofaplasmolyzedElodeacell. Howdoesitcomparetothepreviouspicture? 18 Lab1 Microscopy ProkaryoticCells: Lyngbya(eubacteria: cyanobacteria)1 . Takeacloselookatthesampleinthejar. Whichcolourwouldbestdescribeitsappearance? ___________________ 2 . PrepareawetmountoffreshLyngbyabythefollowingprocedure: Withforcepsoraneyedropper, putaverysmallamountofgreenmatteronacleanslide? Addadropofwaterfromthejar.? Carefullyplaceacoverslipoverit. Makesureitliesflatonthepreparation.

Don’tworryiftherearejustafewairbubbles. Withpractice, yourskillswillimprove. However , iftoomanyairbubblesarepresent, yourpreparationriskstodryoutveryquicklyduringlooking at, compromisingyourobservations. several. Startingwiththe4Xobjective, focusonyourpreparation.? Canyouseenumerousgreenfilaments? _______? Arethefilamentsmoving? __________ 4. Switchtothe10Xthenthe40Xobjectiveandfocususingthefinefocusknobonly:? Doyouseetheindividualcellsmakingupeachfilament? ________? Estimatethewidthofonefilamentinmicrometres: _______ What’sthefilamentwidthinmillimetres(mm)? ________? BEAR IN MIND: Youareworkingwithlivingcells. Workquicklyandkeepyourspecimenwetatalltimes. Useless, dryordamagedbiologicalpreparationsareuseless. Returningthemicroscopesafteruse Aftercompletingallobservations, turnandclickthelowpowerobjective(4X)onthecompoundmicroscopeintoposition. Removetheslidefromthestageandreturnittoitscorrectbox. Wipethestageswithacleanpapertowel. Carefullydisconnectthecamerafromthefirewirecable.

Makesureyouturnedoffthelightoneachmicroscopic lense, thenunplugthepowercordandmakealoosecoilofitaroundtheeyepieces. Returnthemicroscopeinthecupboard. 19 Lab1 Microscopy TAswillcheckthatyouproperlyreturnedthemicroscopesinthe cupboardwiththecordproperlyattachedandnoslidepresentonthestage. Youwilllosemarksforthislab(andotherlabs)ifyoudon’tdoso. Evaluation Ashortquizonmicroscopecomponents, specimenobservationsandmeasurementofobjectswilltakeplaceatthebeginningofLab2.

Beontime, thequizwillstartat2: 30. Referrals: 1? Metricsystem(seealsoappendixIVattheendoflabmanual): 1centimetrecm=10? 2metres(m) 1millimetremm=10? 3metres 1micrometre m=10? 6metres 1nanometrenm=10? 9metres 2? Sizeofcamerafieldofviews(fov): Table2: FieldsofView: OlympusCX41CompoundMicroscopeGoal 4X 10X 40X 100X Camerafieldofview (widthinmm) 1 . seventy five 0. 70 0. 175 0. 070 Table3: FieldsofView”OlympusSZ61TRDissectingMicroscopeZoomSetting 0. 67X zero. 8X 1X

< Prev post Next post >

Find Another Essay On Exploiting My Strengths and Strengthening My Weaknesses

97130863

History Chapter 14 Essential Inquiries 1) How come Kennedy refer to the case of Marbury versus Madison since “epochal? ” Describe the short and long-term outcome to the decision. The ...

13510475

SUBJECT: Role of students inside the purification from the society. DESK OF MATERIAL TOPIC: Function of pupils in the filter of the contemporary society * Purpose of education. 5. Students ...

50093504

The recent réfaction in the taking place of dental care cavities has brought a amendment in circulation of the cavities job in many populations. Presently bulk are very kids and ...

11153765

1 . zero INTRODUCTION This report is usually to address the real-life trouble faced by Body Shop and how the condition can be fixed based on the functions of management. ...

2751267

Patton-Fuller Community Hospital Finances Over the years economic management has been a concept that is certainly flourishing in the world of health care. “Until the sixties, financial supervision in all ...

37728773

Bank The merger of U. S. Citizen Bank and Louisiana Order Bank (LPB) in 1998 triggered a creation of a economic powerhouse obtaining core competencies in commercial lending and innovation. ...

1223597

Education There is a competition between appearance and education. Physical appearance is definitely something that you’ll a first impression on. There are plenty of reasons why education is important to ...

23141158

Pearly Byrd-Lain American InterContinental University SSCI210-1205A-02 Product 2IP/ Ethnocentrism Abstract Through this summary I will be discussing ethnocentrism and the beliefs of the value one puts on of their cultural ...

41435581

Essay, Physiology Muscles are in charge of for all conscious and unconscious movement. It truly is how we maneuver and respond to an environment. You will discover three types of ...

47258281

Plot analysis of “A Rose For Emily” Bill Faulkner’s, “A Rose to get Emily” can be described as story having a southern gothic style. The tragic account is informed to ...
Category: Essay examples,
Words: 740

Published: 02.18.20

Views: 529

A+ Writing Tools
Get feedback on structure, grammar and clarity for any essay or paper
Payment discover visa paypalamerican-express How do we help? We have compiled for you lists of the best essay topics, as well as examples of written papers. Our service helps students of High School, University, College