NYJC 2023 H2 Biology 9744 P3 QP

9744 / H2 Biology / 03 NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATIONS Higher 2 CANDIDATE NAME CLASS BIOLOGY 9744/03 Paper 3 Long Structured and Free-response Questions 20 Sept 2023 2 hours READ THESE INSTRUCTIONS FIRST Write your name and CT on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions in the spaces provided on the Question Paper Section B Answer any one question on the separate Answer 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 no 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. For Examiner’s Use Section A 1 2 3 Section B Total This document consists of 14 printed pages. [Turn over

9744 / H2 Biology / 03 2 Section A Answer all the questions in this section. 1 (a) Tuberculosis (TB) is a major cause of ill health worldwide. Prokaryotic Mycobacterium tuberculosis is the causative agent of TB. Fig. 1.1 shows the longitudinal section of M. tuberculosis , viewed under the transmission electron microscope, with a scale bar representing 500nm. Source: Muhsin Özel, Gudrun Holland/RKI Fig. 1.1 (i) List two features visible in Fig. 1.1 that identify these cells as prokaryotes. [2] (ii) Outline the process by which M. tuberculosis reproduce. [4]

9744 / H2 Biology / 03 3 (iii) Identify and explain one problem of trying to classify prokaryotes such as M. tuberculosis. [2] (b) The World Health Organization (WHO) introduced a strategy in 2015 to end the global TB epidemic. An important part of the strategy is to: • identify people at risk of becoming infected with TB • use methods to prevent transmission of TB. (i) State the mode of transmission of M. tuberculosis to humans. [1] (ii) The BCG vaccination is one method of prevention recommended for use in countries where TB is common. The BCG vaccine contains a non-pathogenic, living form of the microorganism that causes TB. Complete Table 1.1 by using a tick (✓) to identify the type of immunity that develops in a person who has been given the BCG vaccination. Table 1.1 artificial active immunity artificial passive immunity natural active immunity natural passive immunity [1]

9744 / H2 Biology / 03 4 (c) The treatment for people with active tuberculosis (TB) lasts six months and involves a combination of antibiotics. This is usually very effective if the person has a susceptible (non-resistant) strain of M. tuberculosis. Table 1.2 sum