2022 AQA A-level BIOLOGY 7402/1 Paper 1 Question Paper & Mark scheme (Merged) June 2022 Exam

2022 AQA A-level BIOLOGY 7402/1 Paper 1 Question
Paper & Mark scheme (Merged) June 2022 Exam
Whatziszthezfunctionzofzthezcellzmembrane?z-zCORRECTzANSWER-
Tozcontrolzwhatzenterszandzleaveszthezcell,zactszaszazbarrierzbetweenzthezcellzandzitszenvironment.



Whatzstructuralzfeaturezofzthezcellzmembranezallowszsubstancesztozenter/leave?z-zCORRECTzANSWER-
Partiallyzpermeable



Whatziszthezfluidzmosaiczmodel?z-zCORRECTzANSWER-
Stateszthatzazmembraneziszazfluidzstructurez(becausezphospholipidszarezconstantlyzmoving)zwithzaz"mosai
c"zofzvariouszproteinszembeddedzinzit



Describezthezstructurezandzfunctionzofzphospholipids.z-zCORRECTzANSWER-
Hydrophiliczheadzandzhydrophobicztail,zarrangedzinzazbilayerz(headszfacezoutwards,ztailszfacezinwards).zLip
id-solublezsubstanceszonlyzallowedztozpasszthrough.



WhatziszthezfunctionzofzcholesterolzinzthezCSM?z-zCORRECTzANSWER-
Makezphospholipidszpackzmorezcloselyztogether,zrestrictingzthezmovementzofzthezphospholipids,zmakingzt
hezmembranezlesszfluid/morezrigid.



Whatziszsimplezdiffusion?z-zCORRECTzANSWER-
Thez(passive)zmovementzofzparticleszfromzanzareazofzhighzconcentrationztozanzareazofzlowzconcentration.



Whatziszfacilitatedzdiffusion?z-zCORRECTzANSWER-
Thezpassivezmovementzofzazlarge/chargedzparticlezdownzitszconcentrationzgradientzthroughzazcarrier/cha
nnelzprotein.



Whatziszthezprocesszofzfacilitatedzdiffusionzusingzazcarrierzprotein?z-zCORRECTzANSWER-
Largezmoleculezbindsztozazcarrierzproteinzinzmembrane.z

Proteinzchangeszshape.z

Proteinzreleaseszthezlargezmoleculezonzthezoppositezsidezofzthezmembrane.

,Whatziszthezprocesszofzfacilitatedzdiffusionzusingzazchannelzprotein?z-zCORRECTzANSWER-
Channelzproteinszformzporeszinzmembrane.z

Chargedzparticleszcanzdiffusezdownztheirzconcentrationzgradientsztozthezoppositezsidezofzthezmembrane.



Whatzarezthezfactorszaffectingzsimplezdiffusion?z-zCORRECTzANSWER-
Concentrationzgradient,zthicknesszofzexchangezsurfacezandzsurfacezarea.



Whatzarezthezfactorszaffectingzfacilitatedzdiffusion?z-zCORRECTzANSWER-
Numberzofztransportzproteinszandzstrengthzofzgradient.



Whatziszosmosis?z-zCORRECTzANSWER-
Diffusionzofzwaterzthroughzazpartiallyzpermeablezmembranezfromzanzareazofzhighzwaterzpotentialztozanzar
eazofzlowerzwaterzpotential.



Whatzarezthezfactorszaffectingzosmosis?z-zCORRECTzANSWER-Waterzpotentialzgradient.z

Thicknesszofzexchangezsurface.z

Surfacezareazofzexchangezsurface.



OutlinezazmethodzforzRP3z(investigationzofzosmosiszusingzpotatozchips).z-zCORRECTzANSWER-
Producezazserieszofzdilutionszfromz1Mzsucrosezsolutionz(ofzazvarietyzofzdifferentzconcentrations,z0M,z0.2M
,z0.4M,z0.6M,z0.8M,z1M).z

Usezazcorkzborerztozcutzpotatoeszintozidentically-sizedzchips.z

Blotzthemzdryzwithzazpaperztowelzandzmeasurezthezmasszofzeachzusingzazmasszbalance.

Placezonezchipzintozeachzofzthezsucrosezsolutions.z

Putztheztestztubeszintozazwaterzbathzatz30°Czforz20zminutes.z

Takezthemzoutzandzreweighzthezmasszofzthezchips.z

Calculatezthez%changezinzmasszforzeachzchip.



Whatziszactiveztransport?z-zCORRECTzANSWER-
Thezactivezprocesszofzmovingzmoleculeszfromzanzareazofzlowzconcentrationztozanzareazofzhighzconcentrati
onzusingzATP.

, Namezoneztypezofzcarrierzproteinzandzdescribezhowzitzworks.z-zCORRECTzANSWER-Co-transporters.z

Bindztwozmoleculeszatzonce.

Thezconcentrationzgradientzofzonezofzthezmoleculesziszusedztozmovezthezotherzmoleculezagainstzitszownzc
oncentrationzgradient.



Givezanzexamplezofzco-transportzinzmammals.z-zCORRECTzANSWER-Glucose/Na+zco-transport.z

Na+zactivelyztransportedzoutzofzthezileumzepithelialzcellszintozthezbloodzbyzthezNa+/K+zpump.zThiszcreates
zazconcentrationzgradient,zhigherzconcentrationzofzNa+zinzlumenzthanzinsidezcell.z


Na+zDefuseszintozthezepithelialzcellszfromzthezlumenzNa+/glucosezco-transporterzproteins.z

Co-
transporterzcarrieszglucosezintozthezcellzwithzthezsodiumzsozglucosezconcentrationzinsidezthezcellzincrease
s.z

Glucosezdiffuseszoutzofzthezcell,zdownzitszconcentrationzgradient,zthroughzazproteinzchannel,zintozthezbloo
d,zbyzfacilitatedzdiffusion.



Whatzarezthezfactorszaffectingzactiveztransport?z-zCORRECTzANSWER-Speedzofzindividualzcarrierzproteins.z

Numberzofzcarrierzproteinszpresent.z

Ratezofzrespiration/availabilityzofzATP.



3.2.1zCellzStructurez-zCORRECTzANSWER-



Eukaryoticzcellsz-zCORRECTzANSWER-Complex,zincludezallzanimalzandzplantzcellsz(&zalgal/fungalzcells).



Algalzandzfungalzcellsz-zCORRECTzANSWER-
Algal:zsamezorganelleszaszplantzcellszincludingzcellzwallzandzchloroplasts.z

Fungal:zsimilarztozplantzcellszbutzcellzwallszmadezofzchitinzandznozchloroplasts.



Organelleszinzeukaryoticzcells:z-zCORRECTzANSWER-Membrane-
boundzcompartmentszwhichzseparatezmetaboliczreactionszwithinzazcell.



Nucleusz-zCORRECTzANSWER-ContainszchromosomeszwhichzarezmadezfromzproteinzboundzlinearzDNA.z