MFSS P2/ANS 24

[Turn over Name Reg. No Class MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL MAYFLOWER SECONDARY SCHOOL 4EX BIOLOGY 6093/02 Paper 2 [80 Marks] PRELIMINARY EXAMINATION Additional Materials Approved Calculator August 2024 1 hour 45 minutes INSTRUCTIONS TO CANDIDATES Do not start reading the questions until you are told to do so. Write your name, class, and index number on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. FOR EXAMINER’S USE Paper Marks A Total / 70 B Total / 10 Paper 2 Total / 80 Do not use paper clips, highlighters, glue or correction fluid. This paper consists of Section A and Section B. Section A Answer all questions. Write your answers in the spaces provided on the Question Paper. Section B Question 10 is in the Either or Or format. Write your answers in the spaces provided on the Question Paper. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question. Candidates are reminded that all quantitative answers should include appropriate units. Candidates are advised to show all their working in a clear and orderly manner. The use of an approved scientific calculator is expected, where appropriate. This question paper consists of 16 printed pages. Setter: Mr Ng Tze How Vetter: Mrs Marie Huang

2 Section A (70 marks) Answer all the questions in the spaces provided. 1 Pneumococcal diseases are one of the major causes of death worldwide. It is caused by a bacteria called streptococcus pneumoniae. (a) Define the term pathogen. ....................................................................................................................................... ....................................................................................................................................... [1] (b) Antibiotics are drugs that can treat pneumococcal diseases. Complete the table below to list any three of the structures present in a bacterial streptococcus pneumoniae cell. Explain how the antibiotics acts on each of them to destroy this bacterium. Structure How the antibiotic acts on this structure [3] (c) “Superbugs” can develop when bacteria become resistance to antibiotics. Discuss two ways how antibiotic resistance can be reduced. ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... [2]

3 2 In the Artic, food is scarce. The reindeer depends on limited resources like grasses for food. (a) The reindeer is in turn eaten by brown bears. Brown bears are very adaptable like human. They consume a wide range of foods, including ground squirrels and grasses. Ground squirrels are mostly herbivorous and feed on grasses. Construct a food web to show the flow of energy between organisms in this ecosystem. [3] (b) Explain in detail why the food chains found in the above food web consist not more than three organisms. ….................................................................................................................................... ….................................................................................................................................... ….................................................................................................................................... ….................................................................................................................................... ….................................................................................................................................... ….................................................................................................................................... [3]

4 (c) During some time of the year, grasses are not available. The reindeer has to turn to alternative food source. This alternative source of food contains a carbohydrate called lichenan. Reindeer are the only animals that can feed on lichenan. (i) List the three elements present in lichenan. …………………………………………………………………………………………. …………………………………………………………………………………………. [1] (ii) Explain why reindeers are the only animals that can feed on lichenan. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. [2] 3 The figure below shows the changes in the lung volume of an athlete before, during and after his exercise.

5 (a) (i) Calculate the differences in the number of breath s per minute that the athlete took when at rest and when exercise. Differences in the number of breathes per minute: ……………………… [3] (ii) Explain why there is a difference in the number of breaths per minutes taken at rest and while exercising. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. [2] (b) Explain why the volume of air in the lungs remains high in the next ten minutes following the end of exercise. ….................................................................................................................................... ….................................................................................................................................... ….................................................................................................................................... ….................................................................................................................................... [2]

6 4 The figure below shows the changes in the relative concentrations of three substanc