Edexcel a level biology question paper 3 june 2023 salters Nuffield + mark scheme

Pearson Edexcel GCE In Biology A Salters Nuffield (9BN0) Paper 03: General and Practical Applications in BiologyEdexcel 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 visit our qualifications websites at or . Alternatively, you can get in touch with us using the details on our contact us page at 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 education 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: Summer 2023 Question Paper Log Number P71908A Publications Code 9BN0_03_2306_MS All the material in this publication is copyright © Pearson Education Ltd 2023General 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 marks 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 according 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(a) An explanation that makes reference to two of the following: • to pump blood around blood vessels (1) • enabling mass transport (1) • therefore overcoming the limitations of diffusion (1) IGNORE to move blood IGNORE to move blood around the body ALLOW a description e.g. ‘needed to carry oxygen to where it is used’ e.g. ‘organism is too large for {substances/gases/glucose} to diffuse directly to organs’ / distance for diffusion is too great ALLOW surface area to volume ratio too small for diffusion (2) Question number Answer Additional guidance Mark 1(b)(i) An answer that makes reference to the following: • (heart / cardiac muscle) is myogenic (1) IGNORE references to impulses / electrical signals (1)Question number Answer Additional guidance Mark 1(b)(ii) An explanation that makes reference of the following: • the {pacemaker / SAN / sinoatrial node} is in the right atrium (1) • (left atrium) cannot contract without impulses from the SAN (1) ALLOW depolarisation is initiated in the right atrium ALLOW no longer attached to the SAN ALLOW left atrium does not receive impulses needed to stimulate {contraction / beating} (2) Question number Answer Additional guidance Mark 1(b)(iii) An explanation that makes reference to two of the following: • (heart / muscle cells) run out of oxygen (1) • (aerobic) respiration stops (1) • (heart / muscle cells) stop making ATP (1) ALLOW heart (muscle) does not have a blood supply (from the lungs) ALLOW anaerobic respiration takes place ALLOW resulting in accumulation of lactic acid (2)Question number Answer Additional guidance Mark 2(a) • finding r3 (1) • correct volume of neutrophil (1) NB Check table and clip below table Example of calculation 125 / 5 x 5 x 5 / 53 / (10/2)3 523 / 524 / 523.8 / 523.6 / 523.3 ALLOW 39 / 39.3 for both marks (from 1/8th volume given for monocyte) Correct answer with no working gains full marks (2) Question number Answer Additional guidance Mark 2(b)(i) An answer that makes reference to the following: • {engulfing / ingesting / endocytosis} of {pathogen / cell debris / bacteria / virus / fungi / microbes} IGNORE foreign bodies / cell unqualified (1) Question number Answer Additional guidance Mark 2(b)(ii) An explanation that makes reference to the following: • (monocytes / macrophages) {phagocytose / digest / break down} {virus / pathogen} (1) • (monocytes / macrophages) present {virus / antigens} to T cells (1) • (produce) cytokines involved in the immune response (1) ALLOW both can phagocytose {virus / pathogen} ALLOW converse for neutrophils ALLOW exa