Edexcel as level biology question paper 2 ju ne 2023 + mark scheme

Mark Scheme (Results) Summer 2023 Pearson Edexcel GCE In Biology B (8BI0) Paper 02: Core Physiology and EcologyEdexcel 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 P71925A Publications Code 8BI0_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) The only correct answer is D all statements are correct A is not correct because statement 3 and 4 are true B is not correct because statement 4 is true C is not correct because statement 3 is true (1) Question Number Answer additional guidance Mark 1(b) An explanation that includes the following points: • larger organisms have smaller SA/ Vol ratio (1) • some cells far from surface (1) • so diffusion alone cannot supply deliver / transport (oxygen / glucose / nutrients to cells) (1) allow converse (3)Question Number Answer Additional guidance Mark 1(c) An answer that makes reference to the following points Similarities • both have structures that increase surface area (1) • both have a short diffusion distance (1) • both have surfaces that allow oxygen and carbon dioxide to dissolve (1) Differences up to three from • fish live in aquatic environment so do not need to keep surfaces moist / insect air sacs are moist (1) • in insects gases delivered to / removed from cells directly but fish use circulation (1) • fish have gills / lamellae / filaments whilst insects have tracheae/ tracheoles / spiracles (1) • fish have counter current flow (1) At least one similarity and one difference some insects pump air into and out of trachea some have air sacs which store air (4) (Total for Question 1 = 8 marks)estion Number Answer Mark 2(a) The only correct answer is A lenticels B is not correct because stomata do not allow gases to enter stem C is not correct because waxy cuticle does not allow gases to enter stem D is not correct because xylem does not allow gases to enter stem (1) Question Number Answer additional guidance Mark 2(b)(i) • measurement of sides and calculation of area in cm2 • divided by magnification = actual size of area containing 6 stomata 6 stomata ÷ 0.105 = 57 (per cm2 ) Example of calculation 7.6 × 5.1 = 38.8 cm2 allow area from 37.5 to 40.0 (1) area ÷ 370 = 0.105 cm2 area ÷370 (1) .101 – 0.108 =57 (per cm2) allow 55-59 Correct answer with no working gains full marks (3)Question Number Answer additional guidance Mark 2(b)(ii) Number of stomata = 57 x 130 (1) or 7410 allow TE answer to 2bi ×130 (1) Question Number Answer Mark 2(b)(iii) • Distribution of stomata may not be even / the same across leaf surface / only one sample taken / different parts of the leaf may have different number / rounded to whole number (1) (1) Question Number