Pearson Edexcel International A Level Biology Paper 1 Mark Scheme 2023 (WBI12 Unit 2: Cells, Development, Biodiversity and Conservation)

Mark Scheme (Results ) October 2023 Pearson Edexcel International Advanced Subsidiary Level In Biology (WBI12) Paper 01 Unit 2: Cells, Development, Biodiversity and Conservation Edexcel and BTEC Qualifications Edexcel and BTEC qualifications are awarded by Pearson, the UK’s largest awarding body. We provide a wide range of qualifications including academic, vocational, occupational and specific programmes for employers. For further information vi sit our qualifications websites at www.edexcel.com or www.btec.co.uk . Alternatively, you can get in touch with us using the details on our contact us page at www.edexcel.com/contactus . Pearson: helping people progress, everywhere Pearson aspires to be the world’s leading learning company. Our aim is to help everyone progress in their lives through education. We believe in every kind of learning, for all kinds of people, wherever they are in the world. We’ve been involved in educati on for over 150 years, and by working across 70 countries, in 100 languages, we have built an international reputation for our commitment to high standards and raising achievement through innovation in education. Find out more about how we can help you and your students at: www.pearson.com/uk October 2023 Question Paper Log Number P75616A Publications Code WBI12_01_MS_2310 All the material in this publication is copyright © Pearson Education Ltd 2023 General Marking Guidance • All candidates must receive the same treatment. Examiners must mark the first candidate in exactly the same way as they mark the last. • Mark schemes should be applied positively. Candidates must be rewarded for what they have shown they can do rather than penalised for omissions. • Examiners should mark according to the mark scheme not according to their perception of where the grade boundaries may lie. • There is no ceiling on achievement. All marks on the mark scheme should be used appropriately. • All the mark s on the mark scheme are designed to be awarded. Examiners should always award full marks if deserved, i.e. if the answer matches the mark scheme. Examiners should also be prepared to award zero marks if the candidate’s response is not worthy of credit ac cording to the mark scheme. • Where some judgement is required, mark schemes will provide the principles by which marks will be awarded and exemplification may be limited. • When examiners are in doubt regarding the application of the mark scheme to a candidate’s response, the team leader must be consulted. • Crossed out work should be marked UNLESS the candidate has replaced it with an alternative response. Question Number Answer Additional guidance Mark 1(b) An explanation that makes reference to the following points: • {crossing over / recombination} has occurred (1) • (resulting in) B is a recombinant chromatid / chromatid B contains {genetic information / alleles} from {chromatid D / another chromatid / non -sister chromatid } (1) accept chromosome for chromatid accept recombinants have formed ? accept description of crossing over which isn’t specific to A/B accept converse for chromatid A accept gene accept B contains part of {D /another chromatid} ignore exchange of alleles between maternal and paternal {chromatids / chromosomes} ignore (crossing over) of non -sister chromatids unqualified need to be clear which chromatids they are referring to (2) Question Number Answer Mark 1(a) The only correct answer is A centriole B is not correct because spindle fibres develop from a centriole C is not correct because spindle fibres develop from a centriole D is not correct because spindle fibres develop from a centriole (1)