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DNAmolecule

FirstdescribedbyWatson&Crickin1953 DoubleStranded Twistedintoahelix(spiral) SugarPhosphatebackbone Complimentarypairingofbases

Adenine=ThymineCytosine=Guanine

SectionsofDNAcontaingenesresponsibleforproducingproteins

ProteinSynthesis

2stageprocess!

Transcription(transcribe/copy) DNAstrandunwinds complimentarymRNAstrandmade mRNAleavesthoughthenuclearpore

Translation(translate) mRNAattachestoribosome attractstRNAmoleculesshowingtripletcodons tRNAcodonsstickspecificaminoacidstogetherTripletCode(3bases)controlorderofaminoacids makesapolypeptidechain

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Microorganisms

Canbeusedtoproducehumaninsulin Moreeffectivethanpiginsulin Doesnotcauseallergicreactionsinpatients

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Advantages

Widerangeofproductse.g.humaninsulin,medicines,beer Canbeusedtogrowmycoproteinse.g.quorn Quickandefficient easytokeepandmanipulate cangrowanywherei.e.notclimatedependent canusewasteproductsfromotherindustriese.g.quornusingwastefromflour

Disadvantages

optimumconditionsrequiredformostefficientgrowth lowriskofcontamination humanviewsoneatingmicroorganisms

RespirationTheprocessbywhichcellsreleaseenergyfromglucose

AerobicInthepresenceofoxygen

glucose+oxygen carbon+water+energydioxide

glucosedigestionoxygenlungsviathebloodcarbondioxideremovedbyblood

Usesofenergy: temperaturecontrol musclemovement sendingnerveimpulses transportaroundthebody growthandrepair absorbingfood

Occursinmitochondria Largesurfacearea Mitochondriamakeadenosinetriphosphate(ATP) Actsasastoreofenergythatcanbereleasedinstantly

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Exerciseandrespiration

AnaerobicRespiration

Thepointatwhichyourheartcannolongersupplythemusclesfastenough.

glucose lacticacid+energy

Doesnotproducemuchenergy(0.8kJ/gcomparedwith16.1kJ/ginaerobic) Lacticacidisapoisoncausescramp

OxygenDebt

Theamountofextraoxygenneeded(postexercise)tobreakdownanylacticacidbuildup.

Yeastcanrespireanaerobicallyandareusedtoproducebeerandwine

glucose ethanol+carbon+energydioxide

FadDiets

17%of15yearoldsareobese!

Fadfashionableadvicewithnoscientificevidence

BodyMassIndex(BMI)canbeusedtoworkoutifyouareoverweightorobese

BMI=mass(kg)height2(m)

Exceptionstotherule: pregnantwomen children professionalsportsmen/women

Atkins HighproteinverylowcarbohydrateLessinsulinproducedthereforelessfatstorageanduseofalreadystoredfatforenergyIncreasedriskofcancerfromeatinghighlevelsofproteinProductionofketonesmaydamageliver

Usedietbooks,magazinesandtheinternettoresearchsomeotherdietsandexplainhowtheyaresupposedtowork

Dangers Riskofheartdisease/heartattacks Diabetes Strainonjoints

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Whatisgrowth?

AnincreaseinsizeorweightOrganismsofthesamespeciescanveryinsizeSomeanimalsareabletoregeneratee.g.starfish,gecko

Growthfactorscanbeusedtoenhanceperformance

Lookupexamplesofhowtheseworkandthereasonsbehindbanningthem.Whatsideeffectsdotheyhave?

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Growthdependsupon:

DifferentiationStemcellsbecomingothertypesofcelle.gskin,bone,blood,nerve

ElongationCellsgrowinsizeandlengthe.g.plantcells

CellDivisionmakingmanycopiesofcellstoallowfortissueconstruction

Genesinheritedfrommotherandfather

Hormoneshumangrowthhormone(hgh)plantauxins

Dietnutritiontoallowsubstratesforgrowth

Mitosiscelldivision

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MeiosisProductionofgametes

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Providescellsforgrowthandrepair

Createsgametes

Daughtercellsaregeneticallyidentical

Fourdaughtercells

Daughtercellsarediploid

mitosis meiosis

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Summarisetheviewsofpeoplewhoarefororagainstlegalinducedabortion.

Useevidencetodecidewhetherthelawshouldbechangedornot.Givereasonsforyouranswer

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Explorethescientificevidenceregardingtheageandlegalityoftermination

pregnancyupto24weekscanbeterminated 24weeksisthepointatwhichababycansurvivewithoutmedicalintervention canbelaterifthemotherorbabyisatrisk 2doctorsmustagree

Pros

Womenfeelliketheyhaveachoice Riskstomotherreduced Optionstoterminatedisabledoffspring Reducesunwantedbabies Lessstrainonadoption/children'sservices/benefits Rape Ageofmother

Cons

Religionbeliefinthesanctityoflife Seenasaformofcontraception Notequalresponsibilityindecisionmaking Possibilityoffuturecomplicationinconceiving Foetusisabletosurviveoutsidethewombat20weeks Costsmoney

PlantGrowth

Howdoplantsgrow?(Whatdotheyneedtogrow)Howdotheyknowwhichwaytogrow?Howcouldwetestthis?

Canwetrickaseedintogrowingupsidedown?

Canweturnmustardgay?

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PlantResponsesTropisms

Alllivingorganismsaresensitivetochangesintheirsurroundings.

Plantsaresensitivetolight,moistureandgravity.

Theresponsetolightiscalledphototropism.Theresponsetogravityiscalledgeotropism.Theresponsetomoistureiscalledhydrotropism.

Shootsgrowupwardstowardslightandagainsttheforceofgravity.Rootsgrowdownwardstowardsmoistureandinthedirectionoftheforceofgravity.

Hormones

Thewaysinwhichaplantrespondstothesestimuliiscoordinatedbyhormones. Hormonesalsocontrolthegrowthofaplant. Oneplanthormoneiscalledauxin. Auxinismadebycellsinthetipsoftherootsandshoots. Itspeedsupgrowthinshootsandslowsdowngrowthinroots. Unequaldistributionofhormonescausesunequalgrowthratesindifferenttissues.

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CommercialUsesofHormones

Rootingpowdercontainsauxin.Itisappliedtocuttingstostimulatethegrowthofroots.Largenumbersofplantscanbeproducedquickly,somoremoneycanbemade.

Hormonescontrolfruitripening.Producersusechemicalstoslowdowntheripeningoffruits,suchasbananas,duringtransport.Justbeforesale,ripeningcanthenbespeededupusingdifferentchemicalsandawarmertemperatureinthestorerooms.

Weedkillerscontainsynthetichormonesthatstimulatetheplantstogrowveryrapidly.Theirnormalgrowthpatternsaredisrupted.Theybecometallandspindly,andeventuallydie

SeedlessFruitisproducedbysprayingartificialauxinontotheunpollinatedflowers.Thisresultsinfruitwithnopips

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Howdoplantsgrowinspace?

Rootsarenegativelyphototropicsoareabletogrowdownwithouttheforceofgravity

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SelectiveBreeding

Processbywhichhumansdevelopcrops/herdswithdesirablecharacteristics

Advantages

Improvethequalityofmilkfromcattlehighyield/%calcium Safer?thangeneticmodification MoreacceptedthanGM Increasedyieldofwheatbydevelopingdwarfvarieties(lessenergygoesintothestalk) Sheepabletohavemultiplebirths

Disadvantages

Decreaseingeneticdiversityinbreeding Mightnotwork Ethicalissuese.g.BelgianBluemusclecows Takestimeovermanygenerations Increaseingeneticdefects/susceptibilitytodisease

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Cloning

IdenticalTwinsareexamplesofclonesgeneticallyidenticaltoeachother

Aspiderplantproducesnaturalclonesknownas'plantlets'ontheendofrunners

Potatoesgrowbyplantingpotatotuberswhichwillallgrowintoclonedplants

Cuttingswillalsogrowtobeidenticaltotheoriginalplant

Cloning

Farmersabletoproduceexactcopiesoftheirbestcows,sheepandpigs

Lotsandlotsofcopiescanbemade

Plantsdoitnaturallystrawberries/spider

Takeslotsofattemptstogetitright(29/277triesbegantodevelop1/29washealthy)

Highnumberofgeneticrejects

Pronetodisease

Lackofvariationcanresultinwholespeciesbeingwipedoutbydisease(potatofamineinIreland)

Dollylivedaveryshortlife'trueage'oftheoriginaluddercell

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GeneticModificationinplants

GeneticModification

Genesareswitchedoffe.g.'Flavrsavr'tomatoeskeepfresherforlongerwithoutgoingmushy

Switchongenese.g.GoldenRicemakesVitaminAusefulfordevelopingcountrieswithlimiteddiet

GeneTransferUsefulgenesaretransferredintoplantsand/oranimalstoproducedesirablecharacteristicse.g.maizethatcontainsessentialfattyacids

potentialbenefits

ResistancetoPESTSandHERBICIDES ResistancetoenvironmentalfactorsDROUGHT,TEMPERATURE Animalscapableofproducingsubstancesindemande.g.FACTOR8(usedinbloodclotting)

moral&ethicalissues

Unnaturaltomesswithgenes Mayleadtounplannedproblemscrosspollination Transferofunwantedgenestootherorganisms costtofarmers

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GeneTherapyAmoveforwardinmodernmedicinethatwillallowdoctorstotreatpatientswithgeneticdefects

Problems difficultyindeliveringgenetomultipleareas somediseasescausedbygenecombinationsdifficulttoidentifyandreplacingthedefectivegenes findingasafewaytodeliverthegene1patientdiedafterreactingviolentlytothevirusused riskofmutation somedefectivegenesactuallyhavehiddenbenefitssicklecell/malaria ethicsdevelopmentofaraceofsuperhumansagainstthewillof'God' Longtermrisksareunknown

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Complete the diagrams - adding notes on the functions of each organelle

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Plantsandphotsynthesis

As cells develop they can become specialised to perform specific functions in the body

Identify the specialised cells and describe their adaptations in relation to the job that they do

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Osmosis

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ActiveTransport

Movingparticlesagainsttheconcentrationgradient(lowhigh),Energyisneededto'pay'thecarriersinthemembrane

Requiresenergyfromrespiration

Movesdissolvednitratesfromsoilintoroothaircells

Movesmineralionsagainsttheconcentrationgradient

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Cellsaresurroundedbymembranesthatcontrolthemovementofsubstancesintoandoutofthecell.

Sketchthecellmembraneofacell.Adddotstoyourdiagramtoshowtheparticlesofaconcentratedsolutionoutsidethecell,andofadilutesolutioninsidethecell.

Explainwhyparticlescangetintothecell.

Addnotestoyourdiagramtoshowhowtheparticlesmove.Refertothesizeoftheparticles.

Includekeywordsinyourdescriptions

Usethediagramtohelpyouwritenotestoexplainhowactivetransportoccurs.

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Cyanideisapoisonthatstopscellscarryingoutrespiration.Ifcyanidewasaddedtothewatersurroundingaplantsroots,describewhatwouldhappentotheplantsabilitytotakein:

awaterbmineralsalts.

Explainyouranswers.

ExtensionWhenapottedplantbecomeswaterlogged,thelevelofoxygeninthesoildropsdramatically.Whydoesthisreducetherateofmineralsaltuptake?

Foode.g.fruitandvegetables Clothinge.g.hemp/cotton Fuele.g.wood Medicinee.g.Quinine(totreatmalaria)comesfromthebarkofacinchonatree Buildinge.g.wood/rubber

Listsomeusesofplantsandgiveexamples

Whyareplantssoimportant?

Describethechangesinhumansocietybroughtaboutbytheinventionofagriculture

noneedtomovearoundvillagesbecamefixed foodsuppliesbecamereliable newcraftsweredevelopedtofarmandproducefood moneywasinventedtopayforfood lawsandsoldierswereneededtoprotectthevaluableland writingwasinventedtokeeprecords

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RootHairCell

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Photosynthesis

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Investigating photosynthesis

HypothesisThe higher the light intensity the faster the rate of photosynthesis

elodea

sodium hydrogencarbonate solution

beaker

funnel

distanceoflampfromelodea(cm)

Numberofbubbles

producedin1minute

LimitingFactors

Alimitingfactorissomethingthatslowsdownareaction.Agroupofwalkerswillhavetogoasslowlyastheslowestwalkerhebecomesthelimitingfactor.Inthesameway,photosynthesisisaseriesofcomplexreactions.Ifoneofthesereactionsisslowthentheothersjusthavetowait.

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PlantsandWater

Waterisnotalimitingfactor.Aplantthatislackingwaterhasmoreimportantproblemsthanitsrateofphotosynthesis.Plantsshutdowntheirphotosyntheticequipmentintimesofwaterstress.Theeffectofwaterstressisimportantandcanreducetheyieldoftheplantevenifmorewaterisaddedlater

Whatadvicewouldyougivetoagardeneraboutwateringtomatoplants?

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Explainwhyveryfewplantsgrowinthearctic.Usethetermsenzymesandphotosynthesisinyouranswer

Explainwhyveryfewplantscangrowinthedeserteventhoughithasamuchhigheraveragetemperaturethanarainforest?

PhotosynthesisandCarbonDioxide

Thegraphbelowshowsthechangesincarbondioxideconcentrationmeasuredinafieldofgrassduringawarmdayinthesummer

Explaintheshapeofthegraphincludethefollowingkeyideas.Photosynthesis,respiration,temperature,lightintensity

C

O

2

c

o

n

c

e

n

t

r

a

t

i

o

n

(

p

p

m

)

time(hours)0000 0400 0800 1200 1600 2000 2400

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ThecarboncycleTherateofphotosynthesisdependspartlyupontemperature.Usingthecarboncyclemodel,suggesthowglobalwarmingcouldaffecttheamountofcarbondioxideintheatmosphere

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carboncompoundsintheatmosphere

carboncompoundsinanimals

carboncompoundsinbiogas

carboncompoundsinplants

BA

C

D

E

Copythediagramandreplacetheletterswiththecorrectlabelfromthislist:respiration,photosynthesis,decaybybacteria,burning

OutcomeUse the carbon cycle to explain why for thousands of years the amount of carbon dioxide in the Earth's atmosphere was approximately constant and that, during the past two hundred years, the amount of carbon dioxide in the atmosphere has been steadily rising.

Global Warming - do the facts stand up?

Activity

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Complete the task about global warming and make a decision as to whether there is enough evidence to support the theory that the planet is warming up due to the greenhouse effect

Global Warming

Every story has 2 sides - this includes the causes for global warming. One side says this is a natural phenomenon whilst the other links rises in the Earth's temperature with human emissions of greenhouse gases.

Who's to blame?

OutcomeWeigh up the evidence for this theory, as well as that of the opposing theory that human activity causes global warming

Activity

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TheoryAHumanactivity TheoryBNaturalCauses

TheNitrogenCycle

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NitrifyingBacteria inthesoilcanchangeammonia(foundinanimalwasteanddecayingmatterintonitrates.

NitrogenFixingBacteria foundinsoilandrootnodulesOxidisenitrogeninsoilairspacesintonitrates(NO3

)whichplantsarethenabletoabsorbthroughactivetransport

DenitrifyingBacteria foundinwaterloggedsoil.ChangenitratesbackintoNitrogen

RememberLightningcausesNitrogenandOxygentocombineandformNitrateswhicharewashedintothesoilbyrain

Amountofseedproduced(kg/ha)

Area Control +fertiliser +rootnodulebacteria

A 2341 2432 2462

B 2483 2660 3119

Resultsofaninvestigationintotheeffectofusingeithernitrogenfertiliserorrootnodulebacteriaontheamountofseed

producedbyalegumecrop

Presenttheresultsinasuitablegraph.Usethegraphtohelpyoudrawaconclusionabouttheeffectsofrootnodulebacteriaontheamountofseedproduced

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Howdofertilisersharmtheenvironment?

Thisprocessisknownaseutrophication

Organicfarmersoftenpracticecroprotation.Theywillgrowcropplantsinafieldfortwoorthreeyears.Thenextyeartheydonotplantanycropsbutallowclovertogrowandcattletograzethefield.Explainhowthissystemhelpstokeepthesoilfertilewithouttheuseofchemicalfertilisers.

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Whydofarmersusefertilisercontainingnitrateontheirfields?

Readtheinformationinthebox

FishDieinMillPond

ThefishingclubhasblamedlocalfarmersforthedeathoffishinMillppond.Afisherman

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Problems with a rising population

http://www.worldometers.info/worldpopulation/

more roomneeded for houses-less land for farming

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Intensive Farming is an example of how we can maximise food production.Explain some of the cultural, moral and ethical issues attached to intensive farming.

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Use an example of a greenhouse to compare the growth of tomatoes

Biospheresareclosed,selfregulatingsystemscontainingecosystemsincludingartificialonessuchasBiosphere2and,potentially,onesonotherplanetsormoons.

Thefollowingmustbeinbalance(usemustequalproduction)

CarbonDioxideOxygenFood

Howcouldweusetheideaofabiospheretocolonisemars.Whatthingsdoweneedtobeawareof?

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Indicators of Air PollutionLichens are plants that grow in exposed places such as rocks or tree bark. They need to be very good at absorbing water and nutrients to grow there, and rainwater contains just enough nutrients to keep them alive. Air pollutants dissolved in rainwater, especially sulphur dioxide, can damage lichens, and prevent them from growing. This makes lichens natural indicators of air pollution. For example:

Blackspot FungusAnother indicator of air quality is the blackspot fungus on roses. Blackspot fungus grows well on roses in unpolluted areas because it is killed by the presence of sulphur dioxide that would be found in polluted air.

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The diagram shows the contents of a typical household waste bin in 1990. Since 1990 many local councils have introduced recycling schemes

Complete the worksheet to explain why we need to recycle more and landfill less

B2.4 7c

Reasons for recyclingH

Chart A shows how long the estimated

reserves of some non-renewable resources are expected to last on the basis of current and predicted use.

.

1 a What does non-renewable mean?

b Write down another example of a non-renewable resource.

2 How does the evidence in chart A

support the argument for recycling?

Chart B shows the percentage energy saved by recycling materials to make new products rather than using raw materials.

3 How is the energy produced to power the manufacture of new products?

4 Which two materials in household waste save the most energy if they are recycled?

5 The raw materials to make glass are plentiful and the energy savings are low. Does it make sense to recycle glass? Explain your answer

6 Removing ink from paper so that it can be recycled can be both expensive and polluting. If paper is recycled to make paperboard and packaging, it does not

need de-inking. Is it still environmentally sound to recycle paper? Explain your answer.

7 We could reduce the problem of rubbish in other ways, such as the following:

l Burning rubbish in incinerators generates energy that can be used for other processes.

RESOURCE

RESOURCE

Chart A.

Chart B.

l In some European countries, food and other home products have much less packaging than we have in the UK. Less packaging means less to throw away.

l Doorstep delivery of milk means that the glass bottles can be used over and over again.

Carry out research to find the advantages and disadvantages of solving our rubbish problem in different ways. Use your research to write notes for a short talk to answer the question Is more recycling the only solution to the problem of our rubbish in the UK?

128GCSE Additional Science Copymaster File Edexcel Limited 2007

ALUMINIUM

COPPER

IRON

ESTIMATED TIME UNTIL RESERVES RUN OUT (YEARS)

OIL

COAL

MAXIMUM ENERGY SAVING (%)

ALUMINIUM

GLASS

PAPERBOARD PULP

PLASTICS

STEEL

SMART Notebook

Attachments

Recycling.doc

B2.4 7c

Reasons for recyclingH

Chart A shows how long the estimated

reserves of some non-renewable resources are expected to last on the basis of current and predicted use.

.

1 a What does non-renewable mean?

b Write down another example of a non-renewable resource.

2 How does the evidence in chart A

support the argument for recycling?

Chart B shows the percentage energy saved by recycling materials to make new products rather than using raw materials.

3 How is the energy produced to power the manufacture of new products?

4 Which two materials in household waste save the most energy if they are recycled?

5 The raw materials to make glass are plentiful and the energy savings are low. Does it make sense to recycle glass? Explain your answer

6 Removing ink from paper so that it can be recycled can be both expensive and polluting. If paper is recycled to make paperboard and packaging, it does not

need de-inking. Is it still environmentally sound to recycle paper? Explain your answer.

7 We could reduce the problem of rubbish in other ways, such as the following:

l Burning rubbish in incinerators generates energy that can be used for other processes.

RESOURCE

RESOURCE

Chart A.

Chart B.

l In some European countries, food and other home products have much less packaging than we have in the UK. Less packaging means less to throw away.

l Doorstep delivery of milk means that the glass bottles can be used over and over again.

Carry out research to find the advantages and disadvantages of solving our rubbish problem in different ways. Use your research to write notes for a short talk to answer the question Is more recycling the only solution to the problem of our rubbish in the UK?

128GCSE Additional Science Copymaster File Edexcel Limited 2007

ALUMINIUM

COPPER

IRON

ESTIMATED TIME UNTIL RESERVES RUN OUT (YEARS)

OIL

COAL

MAXIMUM ENERGY SAVING (%)

ALUMINIUM

GLASS

PAPERBOARD PULP

PLASTICS

STEEL

SMART Notebook

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