2024 RI H2 Bio P2 QP

© RI 2024 Preliminary Examination 9744/02 [Turn over RAFFLES INSTITUTION 2024 Year 6 Preliminary Examination Higher 2 BIOLOGY 9744/02 Paper 2 Structured Questions 18th September 2024 2 hours Candidates answer on Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your index number, CT group & name in the spaces at the top of this page. Write in a dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 25 printed pages. CIVICS GROUP CANDIDATE NAME INDEX NUMBER 4 S 0 3 2 For Examiner’s Use 1 / 9 2 / 10 3 / 10 4 / 10 5 / 10 6 / 11 7 / 10 8 / 10 9 / 10 10 / 5 11 / 5 Total / 100 Raffles Institution Internal Examination

2 © RI 2024 Preliminary Examination 9744/02 For Examiner’s Use [Turn over Section A Answer all the questions in this section. 1 Fig. 1.1 shows the structure of pancreatic ribonuclease (RNase A) which hydrolyses RNA. Fig. 1.1 (a) (i) Describe two features of RNase A that make it a globular protein. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………. [2] (ii) With reference to Fig. 1.1, describe two structural differences between RNase A and haemoglobin. ……………………………………………………… ...………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………. [2] N-terminus C-terminus

3 © RI 2024 Preliminary Examination 9744/02 [Turn over For Examiner’s Use (b) Christian Anfinsen performed pioneering experiments on the folding of RNase A. He found that RNase A is most stable between pH 2.0 and pH 4.5 at 1000C. Fig. 1.2 shows the changes in the protein structure when he add ed urea and mercaptoethanol to RNase A. The numbers represent the various positions of a pa rticular amino acid in the protein. Fig. 1.2 ( i ) With reference to Fig. 1.2, explain why RN