Aqa a level biology paper 1 2020, Exams of Philology

Download Aqa a level biology paper 1 2020 and more Exams Philology in PDF only on Docsity! AQA A-level BIOLOGY Paper 1 June 2020 *JUN207402101* IB/M/Jun20/E16 7402/1 *JUN207402101* 7402/1 IB/M/Jun20/E16 Please Iwrite Iclearly Iin Iblock Icapitals. Centre Inumber Candidate Inumber Surname I Forename(s) I Candidate Isignat ure I I Ideclare Ithis Iis Imy Iown Iwork. A-level BIOLOGY Paper I1 Thursday I4 IJune I2020 Morning Time Iallowed: I2 Ihours Materials For Ithis Ipaper Iyou Imust Ihave:  a Iruler Iwith Imillimetre Imeasurements  a Iscientific Icalculator. Instructions  Use Iblack Iink Ior Iblack Iball-point Ipen.  Fill Iin Ithe Iboxes Iat Ithe Itop Iof Ithis Ipage.  Answer Iall Iquestions.  You Imust Ianswer Ithe Iquestions Iin Ithe Ispaces Iprovided. IDo Inot Iwrite Ioutside Ithe Ibox Iaround Ieach Ipage Ior Ion Iblank Ipages.  If Iyou Ineed Iextra Ispace Ifor Iyour Ianswer(s), Iuse Ithe Ilined Ipages Iat Ithe Iend Iof Ithis Ibook. I Write Ithe Iquestion Inumber Iagainst Iyour Ianswer(s).  Show Iall Iyour Iworking.  Do Iall Irough Iwork Iin Ithis Ibook. ICross Ithrough Iany Iwork Iyou Ido Inot Iwant Ito Ibe Imarked. Information  The Imarks Ifor Ithe Iquestions Iare Ishown Iin Ibrackets.  The Imaximum Imark Ifor Ithis Ipaper Iis I91. For IExaminer’s IUse Question Mark 1 2 3 4 5 6 7 8 9 10 TOTAL 4 Do Inot Iwrite Ioutsid e Ithe *04* IB/M/Jun20/7402/1 box Figure I2 Iis Ia Idiagram Iof Ione ISGLT1 Icarrier Iprotein. Figure I2 0 1 . I 4 Draw Iphospholipids Ion IFigure I2 Ito Ishow Ihow Ithe Icarrier Iprotein, ISGLT1, Iwould Ifit Iinto Ithe Icell-surface Imembrane. Do Inot Idraw Imore Ithan Ieight Iphospholipids. [2 Imarks] 5 Do Inot Iwrite Ioutsid e Ithe *05* IB/M/Jun20/7402/1 5 10 . Figure I2 Ishows Ithe ISGLT1 Ipolypeptide Iwith INH2 Iat Ione Iend Iand ICOOH Iat Ithe Iother Iend. Describe Ihow Iamino Iacids Ijoin Ito Iform Ia Ipolypeptide Iso Ithere Iis Ialways INH2 Iat Ione Iend Iand ICOOH Iat Ithe Iother Iend. box You Imay Iuse Ia Idiagram Iin Iyour Ianswer. [2 Imarks] Space Ifor Idiagram: Turn Iover Ifor Ithe Inext Iquestion Turn Iover I► 1 0 6 Do Inot Iwrite Ioutsid e Ithe *06* IB/M/Jun20/7402/1 1 To Istudy Ilipid Idigestion, Ia Iscientist Iplaced Ia Itube Iinto Ithe Igut Iof Ia Ihealthy 20-year-old Iman. IThe Iend Iof Ithe Itube Ipassed Ithrough Ithe Istomach Ibut Idid Inot Ireach Ias Ifar Ias Ithe Iileum. The Iscientist Ifed Ithe Iman Ia Imeal Icontaining Itriglycerides Ithrough Ithe Itube. The Iscientist Ialso Iused Ithe Itube Ito Iremove Isamples Ifrom Ithe Iman’s Igut Iat Iintervals Iafter Ithe Imeal. The Iscientist Imeasured Ithe Itype Iof Ilipid Ifound Iin Ithe Isamples. ISome Iof Iher Iresults Iare Ishown Iin ITable I1. Table I1 Sample Time Iof Icollection Iafter Imeal I/ Imin Concentration Iof Ifatty Iacids I/ Img Icm−3 Concentration Iof Itriglycerides I/ Img Icm−3 A 45 2.7 0.6 B 75 3.3 0.0 . Use Iyour Iknowledge Iof Ilipid Idigestion Ito Iexplain Ithe Idifferences Iin Ithe Iresults Ifor Isamples IA Iand IB Ishown Iin ITable I1. box You Ishould Iassume Ithat Ino Iabsorption Ihad Ioccurred. [3 Imarks] 2 0 0 2 9 Do Inot Iwrite Ioutsid e Ithe *09* IB/M/Jun20/7402/1 2 4 . At IQ Ion IFigure I3 Ithere Iis Ia Ismall Iincrease Iin Ipressure Iand Iin Irate Iof Iblood Iflow Iin Ithe Iaorta. Explain Ihow Ithis Ihappens Iand Iits Iimportance. box [2 Imarks] 0 3 . I 3 A Istudent Icorrectly Iplotted Ithe Iright Iventricle Ipressure Ion Ithe Isame Igrid Ias Ithe Ileft Iventricle Ipressure Iin IFigure I3. Describe Ione Iway Iin Iwhich Ithe Istudent’s Icurve Iwould Ibe Isimilar Ito Iand Ione Iway Iit Iwould Ibe Idifferent Ifrom Ithe Icurve Ishown Iin IFigure I3. [2 Imarks] Similarity I Difference I I I I . Use Iinformation Ifrom IFigure I3 Ito Icalculate Ithe Iheart Irate Iof Ithis Idog. [1 Imark] I Turn Iover I► 7 Heart Irate I I beats Iminute–1 3 0 3 0 10 Do Inot Iwrite Ioutsid e Ithe *10* IB/M/Jun20/7402/1 1 Anthocyanins Iare Icoloured Ipigments Ifound Iin Ithe Icell Ivacuole Iof Isome Iplant Icells. IAnthocyanins Icannot Imove Iacross Iundamaged Icell Imembranes. A Istudent Iinvestigated Ihow Ito Iextract Ianthocyanins Ifrom Iblueberries. She Imixed I10 Ig Iof Icrushed, Ifresh Iblueberries Iwith I100 Icm3 Iof Iextraction Isolvent Ifor I1 Ihour. She Iinvestigated Ithree Idifferent Iextraction Isolvents:  E I– IEthanol, Iwater Iand Iacid  F I– IEthanol Iand Iwater  G I– IWater box . When Imaking Iup Iextraction Isolvent IE, Ithe Istudent Iused Ia Ivolume Iratio Iof I70:30:1 Iethanol:water:acid. Tick I() Ione Ibox Ithat Ishows Ithe Imost Iappropriate Ivolumes Ishe Iwould Iuse Ito Imake Iup I100 Icm3 Iof Iextraction Isolvent IE. [1 Imark] 63.6 Icm3 Iethanol, I27.3 Icm3 Iwater, I9.1 Icm3 Iacid 69.3 Icm3 Iethanol, I29.7 Icm3 Iwater, I1.0 Icm3 Iacid 70.0 Icm3 Iethanol, I30.0 Icm3 Iwater, I1.0 Icm3 Iacid 70.7 Icm3 Iethanol, I30.3 Icm3 Iwater, I1.0 Icm3 Iacid 0 4 . I 2 The Istudent Ikept Iconstant:  the Imass Iof Ifresh Iblueberries  the Ivolume Iof Iextraction Isolvent  the Itime Ifor Ithe Imixture Ito Istand. Name Itwo Iother Ivariables Ithe Istudent Ishould Ihave Ikept Iconstant Iduring Ithis Iinvestigation. [2 Imarks] 1 I 2 I 4 0 0 4 11 Do Inot Iwrite Ioutsid e Ithe *11* IB/M/Jun20/7402/1 3 . After I1 Ihour, Ithe Istudent Ifiltered Ithe Isamples. She Iplaced Ithe Ifiltrate Iin Ia Icolorimeter Iand Imeasured Ithe Ilight Iabsorbance. IHer Iresults Iare Ishown Iin IFigure I4. Figure I4 Use Iyour Iknowledge Iof Imembrane Istructure Ito Iexplain Ithe Iresults Iin IFigure I4. [4 Imarks] box Turn Iover I► 4 0 14 Do Inot Iwrite Ioutsid e Ithe *14* IB/M/Jun20/7402/1 Turn Iover I► 15 Do Inot Iwrite Ioutsid e Ithe *15* IB/M/Jun20/7402/1 1 . Describe Ithe Irole Iof IDNA Ipolymerase Iin Ithe Isemi-conservative Ireplication Iof IDNA. [2 Imarks] box Figure I5 Ishows Ithe Ipercentage Iof Irat Icells Iundergoing IDNA Ireplication. ISome Icells Icontained Ia Iprotein Icalled Icyclin ID Iand Isome Icells Idid Inot Icontain Icyclin ID. IAll Icells Iwere Iin Iearly Iinterphase Iat Itime I0 Figure I5 5 0 16 Do Inot Iwrite Ioutsid e Ithe *16* IB/M/Jun20/7402/1 2 3 4 8 . It Itook Iless Itime Ifor I25% Iof Icells Iwith Icyclin ID Ito Ibe Iundergoing IDNA Ireplication Ithan Ifor I25% Iof Icells Iwithout Icyclin ID. Use IFigure I5 Ito Icalculate Ithis Itime Idifference Ias Ia Ipercentage Idecrease. box Show Iyour Iworking. [2 Imarks] Answer I I % . Cyclin ID Istimulates Ithe Iphosphorylation Iof IDNA Ipolymerase, Iwhich Iactivates Ithe IDNA Ipolymerase. Describe Ihow Ian Ienzyme Ican Ibe Iphosphorylated. [2 Imarks] . Some Itumour Icells Icontain Ihigher Ithan Inormal Iconcentrations Iof Icyclin ID. Use IFigure I5 Ito Isuggest Iwhy Ihigher Ithan Inormal Iconcentrations Iof Icyclin ID Icould Iresult Iin Ia Itumour. [2 Imarks] Turn Iover I► 5 0 5 0 5 0 19 Do Inot Iwrite Ioutsid e Ithe Ibox IB/M/Jun20/7402/1 2 0 7 . I 1 Alpha-gal Iis Ia Idisaccharide Ifound Iin Ired Imeat. Alpha-gal Iis Imade Iof Itwo Igalactose Imolecules. IGalactose Ihas Ithe Ichemical Iformula IC6H12O6 Give Ithe Ichemical Iformula Ifor Ithe Idisaccharide, Ialpha-gal, Iand Idescribe Ihow Iit Iis Iformed Ifrom Itwo Igalactose Imolecules. [2 Imarks] Formula I II Description I I . Some Ipeople Ieat Ired Imeat Ifor Imany Iyears Iwithout Ihaving Iany Ireaction, Ithen Ihave Ian Iallergic Ireaction Ito Ithe Ialpha-gal Iin Ired Imeat. An Iallergic Ireaction Iis Icaused Iby Ian Iimmune Iresponse. Draw Ia Ilabelled Idiagram Iof Ian Iantibody Iand Iidentify Ithe Ispecific Ialpha-gal Ibinding Isite. [3 Imarks] 7 0 20 Do Inot Iwrite Ioutsid e Ithe *20* IB/M/Jun20/7402/1 3 . A Itick Iis Ia Ismall Ianimal Ithat Ibites Ihumans Iand Ifeeds Ion Itheir Iblood. IThis Iresults Iin Iproteins Ifrom Ithe Itick Isaliva Ientering Ithe Ihuman Ibody. Scientists Ihave Isuggested Ione Ihypothesis Ifor Ithe Iallergic Ireaction Ito Ialpha-gal Iin Ired Imeat. IThey Ithink Ithat Ian Iearlier Iimmune Iresponse Ito Ia Itick Ibite Ican Icause Ia Iperson Ito Ihave Ian Iallergic Ireaction Ito Ialpha-gal Iin Ired Imeat. box Suggest Ihow Ione Iantibody Ican Ibe Ispecific Ito Itick Iprotein Iand Ito Ialpha-gal. [2 Imarks] Question I7 Icontinues Ion Ithe Inext Ipage Turn Iover I► 7 0 21 Do Inot Iwrite Ioutsid e Ithe Ibox *21* IB/M/Jun20/7402/1 0 7 . I 4 Scientists Itook Iblood Isamples Ifrom Ione Iman Iover Iseveral Iweeks Iand Imeasured Ithe Iconcentration Iof Iantibody Iin Ithe Iman’s Iblood. IDuring Ithis Itime, Ithe Iman Ihad Itwo Itick Ibites Iand Ihad Ian Iallergic Ireaction Ito Ialpha-gal Iin Ired Imeat. The Iscientists’ Iresults Iare Ishown Iin IFigure I7. Figure I7 The Iscientists’ Ihypothesis Iwas Ithat Ian Iearlier Iimmune Iresponse Ito Itick Iprotein Icauses Ithe Iallergic Ireaction. Consider Iwhether IFigure I7 Isupports Ithis Ihypothesis. [3 Imarks] 10 24 Do Inot Iwrite Ioutsid e Ithe *24* IB/M/Jun20/7402/1 4 . The Iscientists Istudied Ifive Iindividuals Ifrom Ieach Ispecies. I Within Ithe Ifive Iindividuals Iof species IT Ithey Ifound Ia Ipercentage Isimilarity Iof I66%. box Use ITable I3 Ito Ievaluate Ihow Ithis Iinformation Iaffects Ithe Ivalidity Iof Ithe Iphylogenetic Itree. [2 Imarks] Turn Iover Ifor Ithe Inext Iquestion Turn Iover I► 8 0 8 25 Do Inot Iwrite Ioutsid e Ithe *25* IB/M/Jun20/7402/1 There Iare Ino Iquestions Iprinted Ion Ithis Ipage DO INOT IWRITE ION ITHIS IPAGE IANSWER I IN I THE I SPACES I PROVIDED box 26 Do Inot Iwrite Ioutsid e Ithe Ibox *26* IB/M/Jun20/7402/1 1 0 9 Scientists Iinvestigated Istomatal Idensity Ion Ileaves Iof Ione Ispecies Iof Itree. Figure I9 Ishows Ithree Iexamples Iof Ithe Isquare Ifields Iof Iview Ithe Iscientists Iused Ito Icalculate Ia Imean Istomatal Idensity. Figure I9 . Calculate Ithe Imean Istomatal Idensity Iin Ithe Ithree Ifields Iof Iview Iin IFigure I9. Give Iyour Ianswer Ias Inumber Iof Istomata Iper Imm2 IShow Iyour Iworking. [2 Imarks] Stomatal Idensity I I per Imm2 Question I9 Icontinues Ion Ithe Inext Ipage Turn Iover I► 9 0 29 Do Inot Iwrite Ioutsid e Ithe IB/M/Jun20/7402/1 1 . Describe Ihow ImRNA Iis Iformed Iby Itranscription Iin Ieukaryotes. [5 Imarks] box 0 1 30 Do Inot Iwrite Ioutsid e Ithe *30* IB/M/Jun20/7402/1 2 . Describe Ihow Ia Ipolypeptide Iis Iformed Iby Itranslation Iof ImRNA. [6 Imarks] box Question I10 Icontinues Ion Ithe Inext Ipage Turn Iover I► 0 1 31 Do Inot Iwrite Ioutsid e Ithe *31* IB/M/Jun20/7402/1 3 15 . Define I‘gene Imutation’ Iand Iexplain Ihow Ia Igene Imutation Ican Ihave:  no Ieffect Ion Ian Iindividual  a Ipositive Ieffect Ion Ian Iindividual. [4 Imarks] box END IOF I QUESTIONS 0 1 34 Do Inot Iwrite Ioutsid e Ithe *34* IB/M/Jun20/7402/1 box Question I number Additional Ipage, Iif Irequired. Write Ithe Iquestion Inumbers Iin Ithe Ileft-hand Imargin. 35 Do Inot Iwrite Ioutsid e Ithe *35* IB/M/Jun20/7402/1 box Question I number Additional Ipage, Iif Irequired. Write Ithe Iquestion Inumbers Iin Ithe Ileft-hand Imargin. 36 Do Inot Iwrite Ioutsid e Ithe *36* IB/M/Jun20/7402/1 box Question I number Additional Ipage, Iif Irequired. Write Ithe Iquestion Inumbers Iin Ithe Ileft-hand Imargin.