Edexcel a level biology a question paper 1 june 2023 salters Nuffield + mark sche me

Mark Scheme (Results) Summer 2023 Pearson Edexcel GCE In Biology A (9BN0 01) Paper 1: The Natural Environment and Species SurvivalEdexcel 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 P71906A Publications Code 9BN0_01_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) The only correct answer is C a place where an organism lives A is incorrect because a group of organisms of different species living in the same area is a community B is incorrect because a group of organisms of the same species living in the same area is a population D is incorrect because the role of an organism is its niche (1) Question Number Answer Additional guidance Mark 1(b)(i) A description that makes reference to three of the following • DNA (from bones) is cut into fragments (1) • { radioactive tracers / fluorescent tags} attached to DNA (1) • (fragments of) DNA loaded onto (agarose) gel / samples placed in wells (1) • electric current passed through (the gel) / potential difference set up (through buffer/ across gel) (1) ALLOW restriction enzymes used on (DNA sample) ALLOW stains such as dye / ethidium bromide ALLOW gel IGNORE agar ALLOW negatively charged fragments move through the gel / DNA fragment moves toward positive electrode IGNORE references to anode or cathode (3)Question Number Answer Additional guidance Mark 1(b)(ii) An explanation that makes reference to the following • (compare) the {size / thickness /position} of bands (1) • if they are closely related there will be (more) similarities (1) (2)Question Number Answer Mark 2(a) The only correct answer is B the number of different species and the number of different alleles A is incorrect because it is not the same species C is incorrect because it is not the same alleles D is incorrect because it is not the same alleles or the same species (1) Question Number Answer Additional guidance Mark 2(b)(i) • 156 as n(n-1) for Ranunculus circinatus 136 as Total for Number (n) in Pond A 3818 as Total for n(n-1) for Pond A All three figures correct for one mark (1) Question Number Answer Additional guidance Mark 2(b)(ii) • correct substitution into equation (1) • correct calculation of diversity (1) Example of calculation (156 x 155) ÷ 9110 = 2.65 /2.654 / 2.7 C