2024_AQA: A-level BIOLOGY Paper 3 (Merged Question paper and marking scheme) Wednesday 19 June 2024

2024_AQA: A-level BIOLOGY Paper 3 (Merged Question paper and marking scheme) Wednesday 19 June 2024 Please write clearly in block capitals. Centre number Surname Forename(s) Candidate signat ure Candidate number I declare this is my own work. A-level BIOLOGY Paper 3 Wednesday 19 June 2024 Materials For this paper you must have:  a ruler with millimetre measurements  a scientific calculator. Instructions Morning  Use black ink or black ball-point pen.  Fill in the boxes at the top of this page.  Answer all questions in Section A.  Answer one question from Section B.  You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. Time allowed: 2 hours For Examiner’s Use Question Mark 1 2 3 4 5 6 7  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). TOTAL  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 78. IB/M/Jun24/G4006/E11 7402/3 A-level Biology Paper 3: Key Areas to Revise This paper is designed to assess your practical and analytical skills, with a focus on the application of knowledge across a variety of biological contexts. Key areas to revise include: 1. Practical Techniques and Experimental Skills: This paper will assess your ability to design, carry out, and analyze biological experiments. Revise techniques used in biology, such as: o Microscopy (calculating magnification, preparing slides) o Enzyme experiments (investigating factors affecting enzyme activity) o Measuring rates of photosynthesis or respiration o Investigating osmosis, diffusion, and transport in cells o Using colorimeters and spectrophotometers Be prepared to interpret experimental results, calculate rates, and draw valid conclusions. 2. Data Analysis and Evaluation: Expect questions that test your ability to analyze and interpret experimental data. Revise how to: o Calculate means, standard deviations, and percentage changes o Interpret graphs, tables, and figures o Evaluate the reliability and validity of data, identifying sources of error and suggesting improvements to experimental methods. 3. Biological Application and Integration: This paper often involves applying biological knowledge to real-world scenarios. Revise how biological concepts can be used to explain issues such as disease, biotechnology, conservation, or environmental challenges. Focus on: o How genetic modification works and its applications o The role of biology in solving global problems, such as climate change and food security o Advances in medical technologies and treatments 4. Advanced Topics: Ensure a strong understanding of advanced topics, including: o The immune system and its practical applications (e.g., vaccines, monoclonal antibodies) o Gene technology and ethical issues o Hormonal control and feedback mechanisms in animals o Plant physiology and responses to environmental stimuli 5. Practical Application of Knowledge: In addition to factual knowledge, you will need to demonstrate your ability to apply it in unfamiliar contexts. This might involve problem-solving exercises or case studies, where you must use your understanding of biology to address specific biological issues. By revising practical skills, data analysis techniques, and applying your biological knowledge to real-world situations, you’ll be prepared for the wide-ranging content of A-level Biology Paper 3. IB/M/Jun24/G4006/E11 7402/3 2 Do not write outside the IB/M/Jun24/7402/3 Section A Answer all questions in this section. You are advised to spend no more than 1 hour and 15 minutes on this section. box 0 1 . 1 In the following passage, each numbered space can be filled with a biological term. Each type of cell has specific molecules on its (1) that identify it. An antibody is a (2) with two (3) binding sites. Antibodies are made and released by (4) cells. Vaccines can provide protection for individuals and populations against disease. The response to a vaccine is an example of (5) immunity. (6) immunity occurs when a large proportion of a population becomes immune to a disease. Write the correct biological term beside each number below that matches the space in the passage. [3 marks] 1 2 3 4 5 6 0 1 . 2 There is currently no effective vaccine available for HIV. Suggest one reason why. [1 mark] 3 Do not write outside the IB/M/Jun24/7402/3 3 . Table 1 shows the action of two antibiotics. Table 1 Antibiotic Action of antibiotic Ciprofloxacin Causes double-stranded DNA to break apart Penicillin Prevents formation of crosslinks between murein chains Using the information in Table 1, explain why each antibiotic is not effective against HIV. box [2 marks] Ciprofloxacin Penicillin Turn over for the next question Turn over ► 6 1 0 4 Do not write outside the box IB/M/Jun24/7402/3 0 2 A student investigated the effect of temperature on the rate of aerobic respiration in woodlice. Figure 1 shows the apparatus they used. Figure 1 The student altered the temperature of the water bath and measured how far the drop of coloured liquid moved every minute for 5 minutes. 0 2 . 1 Other than those stated, suggest two variables the student should have kept constant in this investigation. [1 mark] 1 2 5 Do not write outside the box IB/M/Jun24/7402/3 0 2 . 2 Describe how the student used the apparatus in Figure 1 to reset the drop of coloured liquid back to the right-hand end of the tubing. [2 marks] 0 2 . 3 The student also set up a control experiment. Suggest a suitable control experiment and explain why it was necessary. [2 marks] Control experiment Explanation Question 2 continues on the next page Turn over ► 6 Do not write outside the box IB/M/Jun24/7402/3 0 2 . 4 Figure 2 shows the student’s results at 25 °C The mass of the woodlice in the tube was 3.78 g Figure 2 Use Figure 1 (on page 4) and Figure 2 to calculate the mean rate of oxygen uptake by the woodlice in mm3 s–1 g–1 The formula for the volume of the capillary tubing is πr2l. Use π = 3.14 in your calculation. Show your working and give your answer to 2 decimal places. [3 marks] Answer mm3 s–1 g–1 8 7 Do not write outside the box IB/M/Jun24/7402/3 0 3 . 1 Describe and explain the relationship between surface area to volume ratio of the human body and metabolic rate. [3 marks] Question 3 continues on the next page Turn over ► 8 Do not write outside the box Table 2 shows the height and mass of two adults. IB/M/Jun24/7402/3 3600 1010 Table 2 Person Height / cm Mass / kg A 181 90.90 B 149 62.62 The surface area of a person is estimated using the following formula: Surface area in m2 = �height in cm × mass in kg The volume of a person is estimated using the following formula: Volume in m3 = mass in kg 0 3 . 2 Using suitable calculations, deduce which person has the smaller surface area to volume ratio. Show your working and complete the sentence below. Give your answer to 3 significant figures. [3 marks] Person has the smaller surface area to volume ratio which = 9 Do not write outside the box IB/M/Jun24/7402/3 0 3 . 3 Which is not a possible explanation for the difference in surface area to volume ratio between person A and person B? Tick () one box. [1 mark] Person A and person B have different body shapes. Person A has a higher mass than person B. Person A is taller than person B. 0 3 . 4 Name two structural features of the gills of a fish that increase their surface area. [1 mark] 1 2 Turn over for the next question Turn over ► 8 10 Do not write outside the box IB/M/Jun24/7402/3 0 4 Osteoarthritis (OA) is a disease resulting in joint damage which causes stiffness. Scientists investigated the use of a drug called pralnacasan to treat OA in 80 mice. The scientists:  injected the knee joints of mice with an enzyme to cause joint damage  split the mice randomly into 4 equal groups  fed each group with food containing a different concentration of pralnacasan  after 6 weeks, assessed the stiffness of the knee joints of the mice and scored them using an arbitrary scale. Figure 3 shows their results. Figure 3 0 4 . 1 Describe how the scientists determined the median of the stiffness scores. [1 mark] 11 Do not write outside the box IB/M/Jun24/7402/3 0 4 . 2 Using all the information, evaluate the use of pralnacasan as an effective treatment for OA in humans. [5 marks] Turn over for the next question Turn over ► 6 12 Do not write outside the box IB/M/Jun24/7402/3 0 5 Leigh syndrome (LS) is a rare, recessive, inherited condition. LS is caused by a mutation in any one of more than 75 different genes coding for proteins involved in oxidative phosphorylation. In 80% of people with LS, these mutations occur in nuclear DNA. In 20% of people with LS, these mutations occur in mitochondrial DNA (mtDNA). 15% of the nuclear DNA mutations that cause LS occur in the SURF1 gene. A mutated SURF1 gene codes for a shorter polypeptide than a non-mutated SURF1 gene. 0 5 . 1 Name one type of SURF1 gene mutation and explain how this mutation could lead to production of a shorter polypeptide. [2 marks] Type of mutation Explanation 13 Do not write outside the box Globally, the frequency of LS is 1 in 40 000 IB/M/Jun24/7402/3 In the Faroe Islands, which are 18 isolated islands, the frequency of LS is 1 in 1700 0 5 . 2 The population of the Faroe Islands is 49 053 Estimate the number of people in the Faroe Islands with LS caused by a mutation in the SURF1 gene. Use information in this question and the information on page 12. Give your answer to the nearest whole number. Show your working. [3 marks] Answer people 0 5 . 3 The frequency of LS is higher in the Faroe Islands than globally. Suggest and explain one reason why. [2 marks] Turn over ► 14 Do not write outside the box IB/M/Jun24/7402/3 0 5 . 4 LS usually causes death within the first three years of life. Using all the information in this question, evaluate whether all people should be genetically screened for LS. [3 marks] 10 15 Do not write outside the box IB/M/Jun24/7402/3 [2 marks] Question 6 continues on the next page Turn over ► 0 6 . 1 Define the biological term population. 16 Do not write outside the box IB/M/Jun24/7402/3 Ecologists monitored the biodiversity of birds in a protected woodland. They recorded the number of bird species breeding in the woodland on the same day, every year for a 30-year period. Figure 4 shows their results. Figure 4 0 6 . 2 Which statement correctly represents the species richness of the woodland? Tick () one box. [1 mark] The number of all species present in the woodland The number of all species present in the woodland and their habitats The number of animal and plant species present in the woodland The number of bird species present in the woodland 17 Do not write outside the box IB/M/Jun24/7402/3 0 6 . 3 A student studying the information in this question concluded that all woodlands should be protected to increase the biodiversity of birds. Evaluate the student’s conclusion. [4 marks] 0 6 . 4 It is not possible to extrapolate the data for the number of bird species recorded breeding each year beyond 1979. Explain why. [1 mark] Turn over ► 18 Do not write outside the box In this woodland, the ecologists measured the similarity in the bird community by IB/M/Jun24/7402/3 comparing each year to 1949 using an index of similarity. This index ranges from 1.0 for total similarity to 0.0 for total dissimilarity. Figure 5 shows their results. Figure 5 0 6 . 5 Suggest how the changes in the index of similarity in the bird community provide evidence for the process of succession. [2 marks] 19 Do not write outside the box IB/M/Jun24/7402/3 0 6 . 6 In Figure 5, the index of similarity for the last 10 years remains fairly constant. Name the stage of a succession this represents. Suggest one reason why the index of similarity is not absolutely constant. [2 marks] Stage of succession Reason why the index of similarity is not absolutely constant Question 6 continues on the next page Turn over ► 20 Do not write outside the box IB/M/Jun24/7402/3 The Living Planet Index (LPI) is an index designed to monitor the state of the world’s biodiversity. The LPI is arbitrarily scaled to be 1.0 in 1970, the baseline year. Figure 6 shows the LPI from the Living Planet Report, 2008. The dotted lines represent ± 2 standard deviations from the mean, which includes over 95% of the data. Figure 7 shows an alternative version of Figure 6 published on a news website. Figure 6 Figure 7 21 Do not write outside the box IB/M/Jun24/7402/3 0 6 . 7 The news website published the headline: The LPI shows human activities cause significant decrease in biodiversity. Suggest three reasons why this headline is not valid. Use all the information provided. [3 marks] 1 2 3 Turn over for Section B Turn over ► 15 22 Do not write outside the box Section B IB/M/Jun24/7402/3 Answer one question. You are advised to spend no more than 45 minutes on this section. 0 7 Write an essay on one of the topics below. Either 0 7 . 1 Phosphorus-containing substances and their importance in biological systems. [25 marks] Or 0 7 . 2 The mechanisms and importance of transport within organisms. [25 marks] 23 Do not write outside the box IB/M/Jun24/7402/3 Turn over ► 24 Do not write outside the box IB/M/Jun24/7402/3 25 Do not write outside the box IB/M/Jun24/7402/3 Turn over ► 26 Do not write outside the box IB/M/Jun24/7402/3 27 Do not write outside the box IB/M/Jun24/7402/3 Turn over ► 28 Do not write outside the box IB/M/Jun24/7402/3 29 Do not write outside the box IB/M/Jun24/7402/3 Turn over ► 30 Do not write outside the box IB/M/Jun24/7402/3 31 Do not write outside the box IB/M/Jun24/7402/3 Turn over ► 32 Do not write outside the box IB/M/Jun24/7402/3 END OF QUESTIONS 25 33 Do not write outside the box There are no questions printed on this page IB/M/Jun24/7402/3 DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED 34 Additional page, if required. Write the question numbers in the left-hand margin. Question number IB/M/Jun24/7402/3 Do not write outside the box 35 Additional page, if required. Write the question numbers in the left-hand margin. Question number IB/M/Jun24/7402/3 Do not write outside the box 36 Do not write outside the box IB/M/Jun24/7402/3 Question number Additional page, if required. Write the question numbers in the left-hand margin. Copyright information For confidentiality purposes, all acknowledgements of third-party copyright material are published in a separate booklet. This booklet is published after each live examination series and is available for free download from Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright-holders may have been unsuccessful and AQA will be happy to rectify any omissions of acknowledgements. If you have any queries please contact the Copyright Team. Copyright © 2024 AQA and its licensors. All rights reserved. A-level BIOLOGY 7402/3 Paper 3 Mark scheme June 2024 Version: 1.0 Final MARK SCHEME – A-LEVEL BIOLOGY – 7402/3 – JUNE 2024 Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates participate in and is the scheme which was used by them in this examination. The standardisation process ensures that the mark scheme covers the students’ responses to questions and that every associate understands and applies it in the same correct way. As preparation for standardisation each associate analyses a number of students’ scripts. Alternative answers not already covered by the mark scheme are discussed and legislated for. If, after the standardisation process, associates encounter unusual answers which have not been raised they are required to refer these to the Lead Examiner. It must be stressed that a mark scheme is a working document, in many cases further developed and expanded on the basis of students’ reactions to a particular paper. Assumptions about future mark schemes on the basis of one year’s document should be avoided; whilst the guiding principles of assessment remain constant, details will change, depending on the content of a particular examination paper. No student should be disadvantaged on the basis of their gender identity and/or how they refer to the gender identity of others in their exam responses. A consistent use of ‘they/them’ as a singular and pronouns beyond ‘she/her’ or ‘he/him’ will be credited in exam responses in line with existing mark scheme criteria. Further copies of this mark scheme are available from Copyright information AQA retains the copyright on all its publications. However, registered schools/colleges for AQA are permitted to copy material from this booklet for their own internal use, with the following important exception: AQA cannot give permission to schools/colleges to photocopy any material that is acknowledged to a third party even for internal use within the centre. Copyright © 2024 AQA and its licensors. All rights reserved. 2 MARK SCHEME – A-LEVEL BIOLOGY – 7402/3 – JUNE 2024 Mark scheme instructions to exa