2024 TJC Prelim Biology P3 (Q)

1 [TURN OVER READ THESE INSTRUCTIONS FIRST Write your Center number, index number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Section A Answer all questions in the spaces provided on the Question Paper. Section B Answer any one question in 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 any working or if you do not use appropriate units. The number of marks is given in the brackets [ ] at the end of each question or part question. TEMASEK JUNIOR COLLEGE 2024 JC2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER BIOLOGY 9744/03 Paper 3 Long Structured and Free Response Questions 9 SEPTEMBER 2024 2 hours Candidates answer on the Question Paper. No Additional Materials are required. For Examiner’s Use 1 / 28 2 / 11 3 / 11 4 / 5 / 25 Section A This document consists of 25 printed pages and 3 blank pages.

2 Answer all questions in this section. 1 Tuberculosis (TB) is an infectious disease caused by the bacterium. (a) Define the term infectious disease. …………………….………………………………………………………………………………………… .……………….…..……………………………………………………………………………………… [1] (b) State the name of the pathogenic organism which causes TB and describe its mode o f transmission. Name of organism .……………………………………………………………………………….…… [1] Mode of transmission …………………………………………………………………………………….. …………………….………………………………………………………………………………………… .……………….…..……………………………………………………………………………………… [1] (c) One example of a defence mechanism against pathogens in the lungs involves the action of macrophages. (i) State the location in the body where macrophages are formed. .……………….…..………………………………………………………………………….…… [1] (ii) Outline the mode of action of a macrophage. ……………………..…………………….…………………………………………………………… ……………………..…………………….…………………………………………………………… ……………………..…………………….…………………………………………………………… ……………………..…………………….…………………………………………………………… …………………………….……………….…..……………….………………………………… [2] (iii) It is sometimes possible for the pathogenic bacteria to survive within macrophages. Suggest one way in which these pathogenic bacteria may survive within a macrophage. ……………………..…………………….…………………………………………………………… …………………………….……………….…..……………….………………………………… [1]

3 [TURN OVER (iv) The TB bacterium has many operons in its DNA. Suggest one advantage to the bacterial cell in having operons. ……………………..…………………….…………………………………………………………… ……………………..…………………….…………………………………………………………… …………………………….……………….…..……………….………………………………… [1] Table 1.1 shows recen