Edexcel as level biology question paper 1 june 2023 salters Nuffield + mark scheme

Please check the examination details below before entering your candidate information Candidate surname Other names Centre Number Candidate Number Pearson Edexcel Level 3 GCE Monday 15 May 2023 Morning (Time: 1 hour 30 minutes) Paper reference 8BN0/01 Total Marks Biology A (Salters Nuffield) Advanced Subsidiary PAPER 1: Lifestyle, Transport, Genes and Health You must have: Scientific calculator, HB pencil, ruler Instructions • Use black ink or ball‑point pen. • Fill in the boxes at the top of this page with your name, centre number and candidate number. • Answer all questions. • Show all your working out in calculations and include units where appropriate. • Answer the questions in the spaces provided – there may be more space than you need. Information • The total mark for this paper is 80. • The marks for each question are shown in brackets – use this as a guide as to how much time to spend on each question. • You may use a scientific calculator. • In questions marked with an asterisk (*), marks will be awarded for your ability to structure your answer logically, showing how the points that you make are related or follow on from each other where appropriate. Advice • Read each question carefully before you start to answer it. • Try to answer every question. • Check your answers if you have time at the end. P71922A ©2023 Pearson Education Ltd. N:1/1/1/1/1/2 *P71922A0232*  Answer ALL questions. Write your answers in the spaces provided. Some questions must be answered with a cross in a box . If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 1 The diagram shows a DNA nucleotide. O (a) (i) Complete the diagram to show how a complementary pair of nucleotides would appear in a DNA molecule. (2) (ii) Name two bonds formed between nucleotides in the process of DNA replication. (2) 1 ................................................................................................................................................................................................................................................................................ 2 ................................................................................................................................................................................................................................................................................ *P71922A0332* Turn over 3 (b) The diagram shows the structure of a DNA nucleotide and a modified nucleotide called CeNA. O DNA nucleotide CeNA nucleotide Give one difference in the structure of these two molecules. (1) ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... (Total for Question 1 = 5 marks)4 *P71922A0432*  2 The human circulatory system is composed of the heart and blood vessels. (a) The graph shows pressure changes in the aorta, left atrium and left ventricle during the cardiac cycle. 20 15 10 5 0 –5 Blood pressure / kPa 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Time / s Left ventricle Left atrium Aorta Q R S P (i) At which part of the graph is the left atrioventricular valve starting to close? (1) A P B Q