RI 2023 Prelim H2 Bio P3 QP

© RI 2023 Preliminary Examination 9744/03 [Turn over RAFFLES INSTITUTION 2023 Year 6 Preliminary Examination Higher 2 BIOLOGY 9744/03 Paper 3 Long Structured and Free-response Questions 14th Sept 2023 2 hours Candidates answer on the Question Paper. Additional Materials: Writing paper. READ THESE INSTRUCTIONS FIRST Write your index number, CT group & name in the spaces at the top of this page. Write in 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. Section A Answer all questions in the spaces provided on the Question Paper. Section B Answer any one question in the writing paper provided. 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 your essay question SEPARATELY. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 13 printed pages. CIVICS GROUP CANDIDATE NAME INDEX NUMBER 3 S 0 3 2 Raffles Institution Internal Examination For Examiner’s Use Section A 1 / 28 2 / 12 3 / 10 Section B 4 or 5 / 25 Total / 75

2 © RI 2023 Preliminary Examination 9744/03 For Examiner’s Use Section A Answer all the questions in this section. 1 Immunofluorescence is a technique that scientists use to visualize the distribution and morphological appearance of specific proteins within cells. The indirect immunofluorescence technique involves: 1. The production of specific antibodies that bind to a specific antigen. These are known as primary antibodies. 2. The addition of the primary antibodies to a preparation of cells or tissues fixed on glass slides. 3. The addition of secondary antibodies labeled with fluorescence dye called FITC which will bind to the primary antibodies. 4. Visualization under a fluorescence microscope. Under the light of excitation wavelength, 450nm, FITC will fluoresce. Fig. 1.1 shows the principles of the indirect method of immunofluorescence. Fig. 1.1 Immunofluorescence was used to study cells undergoing cell division. Fig . 1.2 show s a micrograph of a cell. The lighter area shows the position of the fluorescence. Fig. 1.2

3 © RI 2023 Preliminary Examination 9744/03 [Turn over For Examiner’s Use (a) (i) Identify the cell structures that fluoresced in Fig . 1.2 and name the specific antigen (