2024 RI H2 Bio P4 QP

©RI 2024 Preliminary Examination 9744/04 [Turn over RAFFLES INSTITUTION 2024 Year 6 Preliminary Examination Higher 2 BIOLOGY 9744/04 Paper 4 Practical 15th August 2024 2 hours 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions . READ THESE INSTRUCTIONS FIRST Write your index number, CT group and name on all the work you hand in. Give details of the practical shift and laboratory, where appropriate, in the boxes provided. Write in dark blue or black pen. You may use a 2B pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, 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, hand in the Question Paper conta ining your answers. The number of marks is given in brackets [ ] at the end of eac h question or part of the question. This document consists of 18 printed pages. CIVICS GROUP CANDIDATE NAME INDEX NUMBER 4 S 0 3 2 For Examiner’s Use 1 2 3 Total Shift Laboratory Raffles Institution Internal Examination 55

2 ©RI 2024 Preliminary Examination 9744/04 For Examiner’s Use Answer all questions. 1 You are advised to read the whol e of the question before starting the practical work, as you will need to make decisions about how to obtain high quality results using the apparatus and materials provided. You are going to investigate the clotting of milk. Young mammals are fed on milk. To enable efficient digestion of milk it is clotted in the stomach using the protease enzyme, rennin. Rennin converts the soluble protein caseinogen in the milk to an insoluble form called casein. The manufacture of cheese also requires the clotting of milk. This can be done in two ways by:  acidifying the milk  using the enzyme, rennin You are provided with the materials shown in Table 1.1. Table 1.1 labelled contents hazard M 100% milk none E 1% rennin harmful irritant A 1 mol dm-3 hydrochloric acid corrosive If E or A comes into contact with your skin, wash off immediately under cold wa