unit 1
Livingthings:Cells
Thecellisthesmallestunitcapableoflivinganindependentexistence.Mostcellscontainanucleuswhichcontrolsthewaytheywork;theonlycellsinthehumanbodywithnonucleiaretheredbloodcells.Cellsarethebuildingunitsoflivingthingsandmostofthemaretiny.Animalandplantcellshavesimilarinternalstructuresandcomposition,butplantcells,becauseoftheircellulosewalls,haveamorerigidstructure.Animalcellslackchloroplasts,whicharethestructureswhichplantsuseforphotosynthesis.
Essentialfeaturesofeachcellare:themembrane,whichenclosesthecellandrestrictstheflowofsubstancesinandout;andcytoplasm,awateryjellycontainingstructureswhichcarryoutproteinsynthesis,aswellasDNAwhichformsthehereditarymaterial.
Plantsandanimalsgrowbecausetheyaddmaterialtothemselves.Somestudentsmayhavedifficultyunderstandingthis;theymayimaginethatplantsandanimalsgrowbecausetheyswell,ratherlikeaballoon.Thisistrue,inpart,ofplants:individualcellsfillwithwaterandswelltoproducetherapidelongationofshootsandroots.Butmostgrowthisbycelldivision–thesplittingofcellstoincreasethenumber(butnotthevolume)ofcells.Thesubsequentswellingofthenewcellsleadstopermanentgrowth.Someofthesenewcellswillbecomespecialisedstructures.
Cellsaregroupedtogethertoformatissue.Thereareseveralkindsoftissue,eachconsistingofcellsofaparticularkindboundtogether.Somecommonformsoftissueinanimalsaremuscletissue,nervoustissue,epithelialtissue(whichlinestheinsideofthestomachandotherbodyorgans),connectivetissue(whichholdspartstogether)andreproductivetissue,whichproducesthespermandeggs.
Living things:Cells
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unit 1
Livingthings:Cells
Lesson1:DiscoveringcellsLessonpreparationObjectives
identifycells useamicroscopetolookatsomeplantandanimalcells
Science skillsusingamicroscopetolookatcells
EquipmentWarmup: athinsliceofcorkorpreparedslides,amicroscopeActivity1 amicroscope,twomicroscopeslides,twocoverslips,tweezers,largepins,asharpknife,twodroppers,iodinesolution,apieceofonionActivity2 amicroscope,amicroscopeslide,acoverslip,adropper,tweezers,methyleneblue,acleanwoodentoothpick
Key words
cells: thebasicunitsfromwhichlivingthingsarebuiltmicroscopic: somethingsosmallitcanonlybeseenwithamicroscopemulti-cellular: describesalivingthingbuiltfrommanycells;animalsaremulti-cellularunicellular: describesalivingthingthatconsistsofasinglecell
Background informationThecellisthesmallestunitcapableoflivinganindependentexistence.Cellsarethebuildingunitsoflivingthings.Mostofthemaretiny.Animalandplantcellshavesimilarinternalstructuresandcomposition,butplantcells,becauseoftheirrigidcellulosewalls,haveamorerigidstructure.
LessonplanWarm upTellthestudentsaboutRobertHooke:RobertHookewasbornin1635.Hewasagreatscientist–anastronomer,aphysicistandabiologist.HisbookcalledMicrografiacontainshisobservationsandhisdrawings.Lookingatathinsheetofcork,hesawtinyboxes.Theyremindedhimofthelittleroomsinamonastery,sohecalledthem‘cells’.Nearlytwohundredyearslater,MatthiasSchleidenfirstsuggestedthatallplantsaremadefromcells.ThestudentscouldcopyRobertHooke’sactivity,butyouwillneedtoslicecorkextremelythinly.Forthisyouwillneedanextremelysharpblade–forteacheruseonly–orobtainpre-preparedslides.Askthestudentswhattheyknowaboutcellsandtheirimportance.Howmanydifferentbodycellscanyouname?Whatdothesedifferentcellslooklike?Whatistheirfunction?Howdocellsworktogether?Forexample,thecellsinourmusclesandbones?
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Livingthings:Cells
Activity 1 p11Studentslookatpieceofonionunderthemicroscopetoobserveplantcells.
Activity 2 p12Studentslookatsomecellsfromtheinsideoftheircheektoseewhatanimalcellslooklikeunderthemicroscope.
ExtensionThislessoninvitesstudentstofindoutmoreaboutthedifferentsortsofanimalcells.TheycouldbegintheirinvestigationontheInternetwithanumberofsciencewebsites,especiallythosethatshowthemthevarietyofunicellularlife.
Concluding the lesson p13
WhatyouhavelearntanswersAlllivingthingsarebuiltfromcells.Ahumanbodyismulti-cellular–itisbuiltfrombillionsofcells.Thesmallestlivingthingsarejustonecell–theyarecalledunicellularorganisms.Cellsaremicroscopic;theyaresosmalltheycanonlybeseenusingamicroscope.
Checkyourprogressanswers1 thebuildingblocksoflivingthings2 allthecharacteristicsoflife:growth,movement,feeding,respiration,feeling,excretionand
reproduction3 Unicellularorganismshavejustonecell;multi-cellularoneshavemanycells.
AfterthelessonWorkbook p4–5
Answers1 amicroscopic bcell cunicellular dmulti-cellular2 ahumancheekcell bmicro-organism conionskincells3 atube beyepiece cfocusingknob dobjectivelens elimb fstage gbase hmirror4 awithbothhands
bcoarsefocusingknobtowindtheobjectivelensup;finetofocustheimageassharplyaspossible
Lesson2:ComparingplantandanimalcellsLessonpreparationObjectives
identifysomeofthefeaturesofplantandanimalcells describesimilaritiesanddifferencesbetweenplantandanimalcells
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Lesson1:DiscoveringcellsLesson2:Comparingplantandanimalcells
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16 Livingthings:Cells
Science skillsidentifyingcharacteristics
EquipmentExtension: researchfacilities
Key words
cellmembrane: thethinlayerthatenclosesacellcellulose: thesubstanceinthecellwallsofplantsthatgivesthemstrengthchloroplasts: smallgreendiscsinplantcells;chloroplastscontainchlorophyll,thegreensubstancethatplantsusetotraptheenergyofsunlightcytoplasm: theliquidthatfillsmostofthespaceinsidealivingcellnucleus: thepartofalivingcellthatcontrolsitslifeprocessesvacuole: aliquid-filledspaceinacell
Background informationAllcellshaveamembrane,whichenclosesandrestrictstheflowofsubstancesinandout,andajellylikematerialcalledcytoplasmwithinit.Thecellsofplants,bacteriaandfungipossessarigidcellwallthatprotectsthecellandmaintainsitsshape.Mostcellscontainanucleus;theonlycellsinthehumanbodywithnonucleiaretheredbloodcells.Plantcellshaverigidcellulosewallsandchloroplasts–thephotosynthesisingstructures;animalcellsdonot.
LessonplanWarm upWhatdoyourememberfromthelastlessonaboutcells?Whyaretheycalledthebuildingblocksoflife?Whyaretheycalledcells?Whatdotheyresemble?Arecellsallthesame?Howaretheydifferent?Namesomeofthecellsinthehumanbody.Plantandanimalcellsaredifferent.Whymightthatbe?Whatcanplantsdothatanimalscan’t?Whatdowemeanbyphotosynthesis?Whatisthechemicalthatissoimportantforphotosynthesis?I’llgiveyouaclue–it’sgreenincolour.Becausetheylackthisvitalchlorophyll,animalsareunabletophotosynthesiselikeplantsandcannotmaketheirownfood.Butthereareotherdifferencesbetweenplantandanimalcells.
Activity 1 p14
AnswersPlantcell: nucleus,cytoplasm,cellmembrane,cellwall,chloroplast,largevacuoleAnimalcell: nucleus,cytoplasm,cellmembrane
ExtensionUsingillustrationsfrombooksandfromtheInternet,askstudentstodrawageneralisedplantandageneralisedanimalcell.Differentgroupscouldtackleeachkindofcell;andthenthetwocouldbecomparedtoseewhichstructuresareineachcellandwhicharemissing.
Lesson2:Comparingplantandanimalcells
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17Livingthings:Cells
Concluding the lesson p15
WhatyouhavelearntanswersPlantandanimalcellshaveanucleuswhichcontrolshowthecellworks.Thecellisfilledwithcytoplasm,whichismainlywater.Thecellissurroundedbyacellmembrane,whichholdsthecelltogetherandletsdifferentsubstancesinandout.Plantcellshaveastrongcellwallmadefromcellulose.Plantcellsalsohavegreenchloroplaststhathelptheplanttraptheenergyofsunlightandalargevacuolethatcontainschemicals.
Checkyourprogressanswers1 Itcontrolsthewaythecellworks.2 cellmembrane3 no4 spaceinsideacellfilledwithawaterysolution
AfterthelessonWorkbook p6
Answers1 Animal;acellmembrane bnucleus ccytoplasm2 Plant;acytoplasm bnucleus ccellmembrane dcellwall ecellvacuole fchloroplast3 largevacuole;cellwall;chloroplast4 acytoplasm bnucleus cchloroplast dcellmembrane
Lesson3:BuildingtissuesLessonpreparationObjectives
understandhowcellsreproduce knowthattherearedifferenttypesofcells knowthattissuesaremadeupofcellsandthatorgansaremadeupoftissues
Science skillsunderstandingcellreproduction
EquipmentWarmup: sheetsofwallpaperActivity2 achessboardandabagofriceExtension: longstripsofpaper,cardboardboxes
Lesson2:ComparingplantandanimalcellsLesson3:Buildingtissues
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Lesson3:Buildingtissues
Livingthings:Cells
Key words
differentiate: tobecomedifferentdivide: splittingintoparts;acellreproducesbydividingepithelial: theskinoroutertissueofabodyoranorganfoetus: ababydevelopinginthewombpregnant: expectingababy.Pregnancyisthetimeduringwhichababydevelopsintheuterussperm: malesexcellstissue: bodycomponentsmadefromcellsofonetype,muscletissueforexample
Background informationInbiology,anykindofcellularfabricthatoccursinanorganism’sbodyiscalledatissue.Thereareseveralkindsoftissue,eachconsistingofcellsofaparticularkindboundtogether–bycellwallsinplants,orbyakindofmatrixinanimals.So,forexample,nerveandmusclearedifferentkindsoftissuesinanimals.Anorganispartofthelivingbody,suchastheliverorthebrain,withaseparatefunctionorsetoffunctions.Someofthecommonformsoftissuearemuscletissue,nervoustissue,epithelialtissue(whichlinestheinsideofthestomachandotherbodyorgans),connectivetissue(whichholdspartstogether)andreproductivetissue,whichproducesthespermandeggs.
LessonplanWarm upHowmanydifferentorgansarethereinsideyou?Askapartnertolieonasheetofwallpaperanddrawroundthem.Nowdrawinasmanybodyorgansasyoucanintherightplaces.Haveyoufinished?Howmanydifferentorganscanyoufind?Someareinpairs,likekidneysandlungs.Somearesinglestructures.Tellmewhateachorgandoes.Whatisthefunctionofthebrain?Whatdoestheheartdo?Whatisspecialaboutthelungs?Dotheorgansalllookalike?No,theyaremadeupfromdifferenttissuesandtissueisthewordweusetodescribethematerialthatmakesuporgans.Tissuesaredifferentbecausetheycontaindifferentkindsofcell.
Activity 1 p16
Answers
Activity 2 p17Cellsdividetoreplacecellsthatarewornoutordamaged.Newcellsaremadebyothercellsdividingintotwo,growingtofullsizeanddividingagainandsoon.Thisishowalllivingthingsgrowandrepairthemselves.Inourbodies,morethan2millionbloodcellsaremadeeverysecondtoreplaceoldonesdyingatthatrate.Studentsuseachessboardtoworkouthowcellsdivideandmultiplyandhowmanystagesareneededtoproduceallthecellsinthehumanbody.
1 40weeks2 Itdividesagainandagain.
3 no4 Exampleanswer:muscles,nerves,blood.
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19Livingthings:Cells
Activity 3 p17
Answers1d 2b 3c 4a
ExtensionReviewwhatthestudentshavelearntaboutthedifferentkindsofcells.Whatarethemostamazingfactstheyhavediscoveredaboutthemselvesandtheirbodies?Perhapsyoucouldproduceawallofamazingfactsaboutcells.Forexample,nervecellscanbeextremelylongandcanconductnerveimpulsesat160m/s.Cardiacmusclegoesonbeatingthroughoutourliveswithouteverfaltering.Thereare5billionredbloodcellsperlitreofblood.Theyleadahardlifeastheyareforcedathighpressurethrougharteries,veinsandcapillaries.Whitebloodcellsarefiercedefendersagainstinvadingbacteria,whilesomeofthemmaketheproteinthatformsascaboverdamagetoourbodies.Differentcellsaredifferentshapes.Wearegoingtomakeatelevisiongametoidentifydifferentcells.Here’showtodoit.Firstyouneedalongstripofpaperonwhichyoudrawallthedifferentcelltypesyoucanthinkof.Youcanhavesomeduplicates.Youneedaboxtothreadthestripofpaperthrough.Maketwoslotsintheboxandslipthepaperthroughthefirstoneandbackthroughthesecond,sothatwhenyoupullonthepaperitslidesacrossthefrontasifacrossatelevision.Nowyou’rereadytoplaythegame.Askafriendtowatchthecellsslidingacrossinfrontofthemandtonamethetypeofcellbeforeit’sgoneandseehowmanytheycanasyouslidethepaperthroughslowlyandthenasyouslideitthroughfaster.
Concluding the lesson p18
WhatyouhavelearntanswersAwomanbecomespregnantwhenaspermfertilisesheregg.Thefertilisedegggrowsasitscellsdividetomakemoreandmorecells.Asthenumberofcellsgetsbiggerandbigger,thecellsdifferentiatetobecomebloodcells,musclecellsandothercelltypesandafoetusisformed.Atissueisagroupofcellsofonetypethatworktogethertodoajob.Muscletissueproducesmovement;epithelialtissuelinessurfacesinthebody.
Checkyourprogressanswers1 dividemeanstosplittocreatemorecells;differentiatemeanstodevelopindifferentways2 agroupofcellsthatworktogethertodothesamejob3 muscle;nervous;epithelial;connective
AfterthelessonWorkbook p7–8
Answers
Lesson3:Buildingtissues
1 Studentscompletethediagramandthetabletoshowhowcellsdivideandhowmanycellsareproducedineachgeneration.
2 afalse btrue cfalse dtrue
3 aepithelial bdivide cdifferentiate4 anervecell bmusclecells
cepithelialcells dredbloodcells
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