2023 AQA AS BIOLOGY 7401/1 Paper 1 Question Paper & Mark scheme (Merged) June 2023 [VERIFIED]

Please write clearly in block capitals. Centre number Surname Forename(s) Candidate signature 2023 AQA AS BIOLOGY 7401/1 Paper 1 Question Paper & Mark scheme (Merged) June 2023 [VERIFIED] Candidate number I declare this is my own work. AS BIOLOGY Paper 1 Monday 15 May 2023 Morning Time allowed: 1 hour 30 minutes Materials For this paper you must have: • a ruler with millimetre measurements • a scientific calculator. Instructions • Use black ink or black ball -point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • Show all your working. • Do all rough work in this book. Cross through any work you do not want to be marked. For Examiner ’s Use Question Mark 1 2 3 4 5 6 7 8 9 TOTAL Information • The marks for the questions are shown in brackets. • The maximum mark for this paper is 75. *JUN237401101 * IB/M/Jun23/E8 7401/1 2 Answer all questions in the spaces provided. 0 1 . 1 Describe the primary structure of all proteins. [2 marks] 0 1 . 2 This question is about the genetic code. Define universal , non-overlapping and degenerate . [3 marks] Universal Non-overlapping Degenerate *02* IB/M/Jun23/7401/1 Do not write outside the box 5 3 0 2 Figure 1 shows a transmission electron microscope (TEM) image of a Streptococcus bacterium. Figure 1 0 2 . 1 Describe how the appearance of the area containing DNA in a TEM image of a eukaryotic cell would differ from that shown in Figure 1 . [2 marks] 0 2 . 2 Describe one difference between the structure of DNA in a prokaryotic cell and in a eukaryotic cell. [1 mark] Question 2 continues on the next page Turn over ► *03* IB/M/Jun23/7401/1 Do not write outside the box 4 0 2 . 3 Streptococcus bacteria can infect the lungs when air is breathed in and cause lung disease. Describe the mechanism of breathing that causes air to enter the lungs. [3 marks] 0 2 . 4 Some strains of Streptococcus bacteria are more likely to cause lung disease than other strains. Strains that do not cause lung disease are quickly destroyed by phagocytes. Phagocytes are stimulated when they bind to murein on Streptococcus bacteria. Each strain of Streptococcus bacteria has a capsule of different thickness from the others. Suggest how Streptococcus bacteria with a thicker capsule are more likely to survive and so cause lung disease. [2 marks] Do not write outside the box 8 *04* IB/M/Jun23/7401/1