Edexcel a level biology question paper 2 june 2023 salters Nuffield + mark scheme

Mark Scheme (Results) Summer 2023 Pearson Edexcel GCE In Biology A (9BN0 02) Paper 2: Energy, Exercise and CoordinationEdexcel 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 P71907A Publications Code 9BN0_02_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 Mark 1 (a)(i) The only correct answer is C metaphase A is incorrect as centromeres and spindle fibred do not join in anaphase B is incorrect as centromeres and spindle fibres do not join in interphase D is incorrect as centromeres and spindle fibres do not join in telophase [1] Question Number Answer Mark 1 (a)(ii) The only correct answer is C prophase A is incorrect as the nuclear envelope does not start to break down in interphase B is incorrect as the nuclear envelope does not start to break down in metaphase D is incorrect as the nuclear envelope does not start to break down in telophase [1] Question Number Answer Mark 1 (a)(iii) The only correct answer is C prophase A is incorrect as chromatids are not first visible in interphase B is incorrect as chromatids are not first visible in metaphase D is incorrect as chromatids are not first visible in telophase [1]Question Number Answer Additional Guidance Mark 1 (b) An explanation that makes reference to three of the following: • swapping of {alleles / genetic material} (1) • between non-sister chromatids (1) • of a {homologous pair of chromosomes/ bivalent} (1) • resulting in different combinations of alleles (1) ALLOW swapping {sections of DNA / genetic information } ALLOW between maternal and paternal chromosomes [3]Question Number Answer Mark 2(a) The only correct answer is - D the sugar in both eukaryotic and prokaryotic DNA is deoxyribose A is incorrect prokaryotic DNA is not linear and human DNA is not circular B is incorrect prokaryotic DNA is not located in a membrane-bound nucleus C is incorrect the base thymine is not replaced by uracil in the prokaryotic DNA [1] Question Number Answer Additional Guidance Mark 2 (b)(i) A description that makes reference to the following: • a group of genes / a section of DNA (1) • (controlled by a single) {operator/ promotor} / that are transcribed together (1) ALLOW two marks for operator and group of genes associate