AQA A LEVEL BIOLOGY 7402/1 PAPER 1 QUESTION PAPER AND MARKS SCHEME { MERGED} JUNE 2023 COMPLETE AND VERIFIED

AQA A LEVEL BIOLOGY 7402/1 PAPER 1 QUESTION PAPER AND MARKS SCHEME { MERGED} JUNE 2023 COMPLETE AND VERIFIED Pleasewriteclearlyinblockcapitals. BIOLOGY Paper1 Wednesday7June 2023 Afternoon Timeallowed:2 hours Materials Forthispaperyoumusthave: • arulerwithmillimetremeasurements • ascientificcalculator. Instructions • Useblackinkorblackball-pointpen. • Fillintheboxesatthetopofthispage. • Answerallquestions. • Youmustanswerthequestionsinthespacesprovided.Donot write outside the box around each page or on blank pages. • Ifyouneedextraspaceforyouranswer(s),usethelinedpagesattheendof this book. Write the question number against your answer(s). • Showallyour working. • Doallroughworkinthisbook.Crossthroughanyworkyoudonot want to be marked. Information • Themarksforthequestionsareshowninbrackets. • Themaximummarkforthispaperis 91. Answerallquestionsinthespacesprovided. outsidethebox 1Givethethreestructuralfeaturesfoundin allvirusparticles anddescribethefunction of one of these features. [2 marks] 1 2 3 Functionofonenamedfeature 2Explainwhyvirusesaredescribedasacellularandnon-living. [2 marks] 3Giveonereasonwhyantibioticsarenoteffectiveagainstviruses. [1 mark] 1Chitinisapolysaccharide. Thechitinmonomerisaβ-glucosemoleculewithoneOH groupreplacedbyanNHCOCH3group.NHCOCH3canberepresentedbyN(Ac). Figure1showsthemonomerthatformschitinandthechitinpolymer. Figure1 Chitinhasasimilarstructuretocellulose. Use Figure1todescribethreewaysthestructureofchitinissimilartothestructure of cellulose. box [3 marks] 1 2 3 Question2continuesonthenextpage Turnover► 2Chitinkeepsthetracheaeopeninthetrachealsystemofgasexchangeinaninsect. Gasexchangedoesnotoccurinthetracheae. Explaintheimportanceof oneadaptationofthegasexchangesurfaceinthetracheal system of an insect. box [2 marks] 3Ligninisapolymerfoundinthewallsofxylemvesselsinplants.Ligninkeepsthe xylem vessel open as a continuous tube. Explaintheimportanceofthexylembeingkeptopenasacontinuoustube. [3 marks]