2023 AQA A-level BIOLOGY 7402/1 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 A-level BIOLOGY 7402/1 Paper 1 Question Paper & Mark scheme (Merged) June 2023 [VERIFIED] Candidate number I declare this is my own work. A-level BIOLOGY Paper 1 Wednesday 7 June 2023 Afternoon Time allowed: 2 hours 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. Information • The marks for the questions are shown in brackets. • The maximum mark for this paper is 91. For Examiner ’s Use Question Mark 1 2 3 4 5 6 7 8 9 10 TOTAL *JUN237402101 * IB/M/Jun23/E9 7402/1 2 Answer all questions in the spaces provided. 0 1 . 1 Give the three structural features found in all virus particles and describe the function of one of these features. [2 marks] 1 2 3 Function of one named feature 0 1 . 2 Explain why viruses are described as acellular and non -living. [2 marks] 0 1 . 3 Give one reason why antibiotics are not effective against viruses. [1 mark] Do not write outside the box 5 *02* IB/M/Jun23/7402/1 3 0 2 . 1 Chitin is a polysaccharide. The chitin monomer is a β -glucose molecule with one OH group replaced by an NHCOCH 3 group. NHCOCH 3 can be represented by N(Ac). Figure 1 shows the monomer that forms chitin and the chitin polymer. Figure 1 Chitin has a similar structure to cellulose. Use Figure 1 to describe three ways the structure of chitin is similar to the structure of cellulose. [3 marks] 1 2 3 Question 2 continues on the next page Turn over ► *03* IB/M/Jun23/7402/1 Do not write outside the box 4 0 2 . 2 Chitin keeps the tracheae open in the tracheal system of gas exchange in an insect. Gas exchange does not occur in the tracheae. Explain the importance of one adaptation of the gas exchange surface in the tracheal system of an insect. [2 marks] 0 2 . 3 Lignin is a polymer found in the walls of xylem vessels in plants. Lignin keeps the xylem vessel open as a continuous tube. Explain the importance of the xylem being kept open as a continuous tube. [3 marks] Do not write outside the box 8 *04* IB/M/Jun23/7402/1