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 100. • 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. You must have: Ruler, pencil and calculator Biology A (Salters Nuffield) Advanced PAPER 2: Energy, Exercise and Co‑ordination Time 2 hours 9BN0/02 Pearson Edexcel Level 3 GCE *P67091A0228* 2  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 Blood from the lungs returns to the left side of the heart in the pulmonary vein. The pulmonary vein does not have valves. (a) (i) Describe how the atrioventricular (AV) valves work during one cardiac cycle. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (ii) The structure of the pulmonary vein is different from the structure of the pulmonary artery. Explain how this difference is related to the function of the pulmonary vein. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... *P67091A0328* Turn over    3  (b) An angiogram is an X‑ray image of a blood vessel. To produce an angiogram, a dye is added to the blood. The dye does not let X‑rays through. This angiogram shows the location of a blood clot (labelled Q) in a vein near the hip of a patient. Q (Source: © ZEPHYR/SCIENCE PHOTO LIBRARY) (i) Which of the following is released by platelets at location Q? (1) A fibrin B prothrombin C thrombin D thromboplastin (ii) Which of the following is an enzyme that converts a soluble plasma protein into an insoluble protein at location Q? (1) A fibrinogen B prothrombin C thrombin D thromboplastin (Total for Question 1 = 6 marks) *P67091A0428* 4  2 The human brain is an organ that has a range of functions. (a) A student produced a table linking three descriptions of brain function to a labelled diagram of the brain. Label Description of function of labelled region in brain 1 Site where more synapses are formed during the critical window for vision 2 Required for the fine motor skills to draw a straight line 3 Area that sends impulses to the sinoatrial node (SAN) in response to a lowering of blood pH Which diagram of the brain correctly matches the table? (1) 1 3 2 2 1 3 Diagram A Diagram B 3 1 2 3 2 1 Diagram C Diagram D *P67091A0528* Turn over    5  (b) There are various types of scan that can be used to study the brain. (i) Describe why a region of the brain might appear lighter in an image obtained by a functional magnetic resonance image (fMRI) scan.