2018 VJC H2 Biology Prelims Paper 3 Questions

1 VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION 2018 NAME : ____________________________________ CT CLASS : ____________________________________ H2 BIOLOGY 9744/03 Paper 3 Long structured and free-response questions 2 hours READ THESE INSTRUCTIONS FIRST Write your Name and CT Class on the cover page of this paper. Write in dark blue or blue pen. You may use a soft pencil for any diagrams or graphs. Do not use any 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. 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 the appropriate units. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 13 printed pages and 1 blank page. For Examiner’s Use 1 2 3 Section B Total

2 Section A Answer all the questions in this section. 1 Pneumonia is disease caused by the gram-positive pneumococcal bacteria. Pneumococcal infections result in an infl ammatory condition of the lung affecting primarily the small air sacs known as al veoli. Hence, the symptoms of pneumonia include dry cough, chest pain, fever, and difficulty in breathing. Pneumonia affects approximately 450 millio n people globally (7% of the population) and results in about 4 million de aths per year. Up to 40% of these infections were caused by pneumococcal bacteria that were resistant to at least one antibiotic. Due to the severity of pneumonia and the rise in antibiotic resistance among bacteria, vaccines have been developed to protect individuals against the disease. (a) Evaluate the effectiveness of vaccines agains t the rise of antibiotic-resistant strains of pnemococcal bacteria. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. …………………………………………………………………………………………….… [4] With the continuing threat of antibiotic resistance, bacteriophage therapy is employed as a mean to treat bacterial infections. (b) Describe how a typical T4 bacteriophage can work against an antibiotic-resistant bacterium. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. …………………………………………………………………………………………….…[3]

3 (c) A subset of the bacteriophage population, termed as “superspreaders”, is observed to release substantial amounts of intac t, transformable bacteri a plasmid DNA along with the release of