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Download AQA A-LEVEL BIOLOGY Paper 2 Mark Scheme & Question Paper June 2024 and more Exams Biology in PDF only on Docsity!
Actual 2024 AQA A-LEVEL BIOLOGY 7402/2 Paper 2 Merged Question Paper + Mark Scheme AQA= Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature | declare this is my own work. A-level BIOLOGY Paper 2 Friday 14 June 2024 Morning Time allowed: 2 hours Materials : For this paper you must have: For Examines s Use ¢ aruler with millimetre measurements Question Mark * ascientific calculator. 1 Instructions 2 e Use black ink or black ball-point pen. 3 Fill in the boxes at the top of this page. 4 « Answer all questions. 5 e You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. 8 ¢ If you need extra space for your answer(s), use the lined pages at the end of 7 this book. Write the question number against your answer(s). 8 e Show all your working. 9 ¢ Do all rough work in this book. Cross through any work you do not want to be marked. 10 TOTAL Information « The marks for the questions are shown in brackets. e The maximum mark for this paper is 91. IB/M/Jun24/G4006/E7 74 02/2 2201 Do not write " sé a outside the Answer all questions in the spaces provided. box Figure 1 shows a drawing of a neuromuscular junction. Figure 1 fo[4].[1| Name the parts labelled A to D. [2 marks] 0 ao WUD YP IB/M/Jun24/7402/2 IM Do not write outside the [o[2].[1] Figure 2 shows part of a relaxed myofibril. Bak, Figure 2 -band | band Length of sarcomere = 2 1m The myofibril represented in Figure 2 has 34 sarcomeres. The length of every sarcomere is 2 um After contraction of this myofibril, the length of each sarcomere changed by 20%. Use the information provided to calculate the length of the myofibril after contraction. Give your answer in mm and in standard form. Show your working. [2 marks] Answer mm 04 IB/M/Jun24/7402/2 Do not write outside the [0[2].[2] Which statement correctly describes the changes in length in a sarcomere when a box myofibril contracts? Tick (“) one box. [1 mark] H-zone decreases, I-band increases, A-band decreases H-zone increases, I-band decreases, A-band decreases H-zone decreases, I-band decreases, A-band no change H-zone increases, |-band increases, A-band no change [o[2].[3| Fast muscle fibres have a higher concentration of glycogen than slow muscle fibres. Explain how the difference in glycogen concentration is related to the different properties of these muscle fibres. [4 marks] Turn over > 05 IB/M/Jun24/7402/2 [0] 3].[2] Give three environmental factors that should be controlled when measuring the rate of photosynthesis in this investigation. Do not include features of the plant in your answer. [2 marks] 1 2 3 [0[3].[3| Describe how the products of the light-dependent reaction are used in the light-independent reaction to produce triose phosphate. Do not include the role of ribulose bisphosphate (RuBP) in your answer. [3 marks] Do not write outside the box Turn over > IMI IB/M/Jun24/7402/2 {o]4].[1] {o]4].[2] 08 Do not write outside the box In fruit flies, a gene for body colour has a dominant allele for grey body, G, and a recessive allele for black body, g. Explain how you would determine if the genotype of a grey fly is homozygous or heterozygous for body colour. [2 marks] In fruit flies, males are XY and females are XX. A cross between a grey-bodied male fly and a black-bodied female fly produced some black-bodied females. Explain how this shows that the gene for body colour is not sex-linked. [1 mark] IB/M/Jun24/7402/2 10 Do not write outside the [0[5].[1] A weed is a plant growing where it is not wanted. Fat hen is a weed which grows in box some crop fields. Describe how you could estimate the number of fat hen plants in a field. [5 marks] IB/M/Jun24/7402/2 11 Do not write outside the [0[5].[2] In potato plant fields, fat hen plants can grow up to a height of 2 m and absorb large box, quantities of nutrients from the soil. Fat hen has a negative effect on the growth of potato plants. Use the information provided to explain why. In your answer, name the type of competition occurring between fat hen plants and potato plants. [3 marks] Question 5 continues on the next page Turn over > IB/M/Jun24/7402/2 IM 13 Do not write outside the box Turn over for the next question DO NOT WRITE/ON THIS PAGE ANSWER IN THE/SPACES PROVIDED Turn over > IM IB/M/Jun24/7402/2 14 [o[6].[1| Describe the myogenic stimulation of the heart and how the regular contraction of the atria and ventricles is coordinated. Do not include the autonomic nervous system in your answer. [5 marks] IB/M/Jun24/7402/2 Do not write outside the box 16 Do not write outside the [0 | [1] BamH1 and Hindlll are both restriction endonucleases. Box Figure 4 shows the positions where these enzymes cut a linear molecule of DNA. Figure 4 DNA molecule Key | Position DNA molecule cut by BamH1 | Position DNA molecule cut by Hindlll In two experiments, multiple copies of the DNA molecule shown in Figure 4 were all completely cut into fragments using these restriction enzymes. The DNA fragments produced were then separated by electrophoresis. Experiment 1 - DNA cut into fragments using BamH1. Experiment 2 — DNA cut into fragments using BamH1 and Hindill. 16 IB/M/Jun24/7402/2 17 Do not write wutside the Complete Figure 5 to show the relative positions of the bands following tN electrophoresis in experiments 1 and 2. [2 marks] Figure 5 Experiment 1 Experiment 2 BamH1 BamH1 and Hindlll Direction of electrophoresis {o[7].[2| Suggest how you could determine the size of the different DNA fragments produced in these experiments. [2 marks] Turn over > IB/M/Jun24/7402/2 19 Do not write outside the box Turn over for the next question DO NOT WRITE/ON THIS PAGE ANSWER IN THE/SPACES PROVIDED Turn over > IB/M/Jun24/7402/2 Cell wall plasticity / arbitrary units (oso) (o[s].[1] IMU 20 Do not write outside the Plant cells are surrounded by a rigid cell wall. Cell wall plasticity refers to the ability of Box, a cell wall to stretch permanently. IAA is a growth factor which can activate enzymes that loosen the cell wall. Scientists investigated the effect of IAA concentration on cell wall plasticity and the growth of stem segments. Figure 6 shows some of the scientists’ results. Figure 6 Mean growth 2 of stem /mm (e—) ll ie) (e) 10-8 10-7 10-6 10-5 IAA concentration / mol dm-> Use the information provided to explain the relationship between IAA concentration, cell wall plasticity and mean growth of the stem segments. [2 marks] IB/M/Jun24/7402/2 
