AQA AS BIOLOGY 7401/2 PAPER 2 QUESTION PAPER AND FINAL MARKSHEME JUNE 2022 {MERGED}.

AQA AS BIOLOGY 7401/2 PAPER 2 QUESTION PAPER AND FINAL MARKSHEME JUNE 2022 {MERGED}. 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. Information • The marks for the questions are shown in brackets. • The maximum mark for this paper is 75. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. AS BIOLOGY Paper 2 2 *02* IB/M/Jun22/7401/2 Do not write outside the Answer all questions in the spaces provided. box 0 1 . 1 What is a gene? [1 mark] 0 1 . 2 Describe how the production of messenger RNA (mRNA) in a eukaryote cell is different from the production of mRNA in a prokaryote cell. [2 marks] 0 1 . 3 Scientists produced a short, single-stranded, artificial nucleic acid, called PNA. The PNA binds to a small section of DNA. The scientists introduced PNA into cells and discovered that these cells produced less mRNA than cells that did not contain PNA. Suggest how PNA affected the transcription of the section of DNA. [2 marks] 3 *03* Turn over ► IB/M/Jun22/7401/2 Do not write outside the 0 1 box . 4 Describe the role of ATP in the process of translation in protein synthesis. [2 marks] Turn over for the next question 7 4 *04* IB/M/Jun22/7401/2 Do not write outside the box 0 2 . 1 What term is used to describe the different structures of α-glucose and β-glucose? [1 mark] 0 2 . 2 A student investigated the difference in the reducing sugar content of two fruit juices. He performed a biochemical test on each fruit juice using Benedict’s solution. He then used a colorimeter with each test result. Describe how the results from the colorimeter can identify the fruit juice containing the higher sugar content. [1 mark] 0 2 . 3 The student controlled variables in the test using Benedict’s solution. Give two variables the student controlled. [2 marks] 1 2 5 *05* Turn over ► IB/M/Jun22/7401/2 Do not write outside the 0 2 box . 4 Apples consist of flesh tissue which surrounds core tissue where the seeds are located. A student has an apple with a mass of 180 g The ratio of flesh tissue to core tissue in this apple is 5:1 8% of the whole apple is sugar. Calculate the mass of sugar in the flesh tissue. Show your working. [2 marks] Answer g 0 2 . 5 Iodine solution stains fresh apple tissue black. When iodine solution is added to apples stored for a week, the stain is less black. The water potential of apple juice decreases when apples are stored. Suggest why the water potential of apple juice decreases when apples are stored. [2 marks] Turn over for the next question 8 6 *06* IB/M/Jun22/7401/2 Do not write outside the box 0 3 Figure 1 is an image of part of a cell lining the ileum. Figure 1 0 3 . 1 Describe and explain two ways that structures shown in Figure 1 increase the rate of absorption by this cell. [2 marks] 1 2 7 *07* Turn over ► IB/M/Jun22/7401/2 Do not write outside the box 0 3 . 2 An ileum cell without microvilli has 7.85 µm2 of cell surface in contact with digested substances. A scientist found an ileum cell with 1000 microvilli. The microvilli cover the entire cell surface in contact with digested substances. Microvilli are 0.1 μm in diameter and 1 μm in length. The surface area of a microvillus is calculated using this equation 2 πrl + πr 2 where π is 3.14, r is the radius, l is the length. Calculate the ratio of the area of the ileum cell surface with microvilli to the area of ileum cell surface without microvilli. Show your working. [2 marks]