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w w ap eP m e tr .X w om .c s er UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Advanced Subsidiary Level and Advanced Level * 7 5 3 0 3 8 1 4 3 9 * 9693/04 MARINE SCIENCE Data-Handling and Free-Response October/November 2013 Paper 4 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. 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. Section A Answer all questions. Write your answers in the spaces provided on the question paper. Section B Answer all questions. Write your answers in the spaces provided on the question paper. For Examiner’s Use Electronic calculators may be used. 1 2 3 4 Total This document consists of 11 printed pages and 1 blank page. DC (NF/CGW) 66938/4 © UCLES 2013 [Turn over 2 Section A Answer both questions in this section. 1. A laboratory investigation into photosynthesis by marine algae was carried out. A mark was made 20 cm above the base of a 100 cm3 measuring cylinder. The measuring cylinder was then filled with saline solution, to which sodium hydrogencarbonate was added. Green algae were trapped in beads of a transparent, jelly-like substance called sodium alginate. Ten of these beads were added to the measuring cylinder. The beads sank to the bottom A lamp was placed 15 cm from the measuring cylinder, as shown in Fig. 1.1. 20 cm measuring cylinder saline solution plus sodium hydrogencarbonate alginate beads containing green algae lamp Fig. 1.1 © UCLES 2013 9693/04/O/N/13 For Examiner’s Use 3 The time taken for each bead to float to the surface was measured. The results are shown in Table 1.1. For Examiner’s Use Table 1.1 (a) (i) bead number time taken for bead to rise / s 1 135 2 166 3 174 4 183 5 185 6 185 7 196 8 210 9 292 10 295 Using your knowledge of photosynthesis, suggest why the beads floated after illumination. ............................................................................................................................. [1] (ii) Suggest why the sodium hydrogencarbonate was added to the saline solution. ............................................................................................................................. [1] (iii) The rate at which the beads rise can be calculated from the time taken to rise a given distance. Use the information given in Fig. 1.1 and Table 1.1 to calculate the mean rate at which the beads rise. © UCLES 2013 9693/04/O/N/13 [2] [Turn over 4 (b) The beads were then exposed to different wavelengths of light. For Examiner’s Use The results are shown in Fig. 1.2. 14 12 10 mean rate of bead rising / cm s-1 8 6 4 2 0 400 450 blue 500 550 600 green 650 700 red wavelength of light / nm Fig. 1.2 (i) With reference to Fig. 1.2, describe how changing the wavelength of light affects the rate of photosynthesis. .................................................................................................................................. .................................................................................................................................. .................................................................................................................................. .................................................................................................................................. .................................................................................................................................. ............................................................................................................................. [3] (ii) Using your knowledge of photosynthesis, explain the pattern of results shown in Fig. 1.2. .................................................................................................................................. .................................................................................................................................. .................................................................................................................................. ............................................................................................................................. [2] © UCLES 2013 9693/04/O/N/13 5 (c) Fresh alginate beads containing algae were made and allowed to settle to the bottom of the measuring cylinder. For Examiner’s Use The beads were left in complete darkness for 24 hours. During this period, these beads also rose to the surface. Suggest why these beads rose. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... ..................................................................................................................................... [2] [Total: 11] © UCLES 2013 9693/04/O/N/13 [Turn over 6 2. An ecological investigation was carried out into the effects of an extensive aquaculture system located in an estuary. The aquaculture was designed to produce large quantities of shrimps. For Examiner’s Use Samples of water were taken at 10 m intervals downstream from the aquaculture site. The turbidity, nitrate concentration and oxygen concentration of the samples were determined. Turbidity is a measure of cloudiness which is affected by the quantity of sediment suspended in the water. The results are shown in Fig. 2.1. 110 100 90 80 70 turbidity / 60 arbitrary units 50 40 30 20 10 10 turbidity 8 nitrate and oxygen 6 concentration / mg dm-3 nitrate 4 oxygen 0 2 20 40 60 0 100 80 distance from aquaculture site / m Fig. 2.1 Fish were netted at 10 m intervals downstream from the aquaculture site. The numbers of salmon and carp (a freshwater fish) are shown in Fig. 2.2. 16 ×salmon 14 12 × × × × 10 number of fish caught × 8 × × × × 6 × × 4 × 2 0× 0 × × × 20 × × 40 × 60 80 distance from aquaculture site / m Fig. 2.2 © UCLES 2013 9693/04/O/N/13 ×carp 100 7 (a) Explain the pattern shown by the nitrate concentration in Fig. 2.1. .......................................................................................................................................... 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[3] (b) Explain the pattern shown by the oxygen concentration in Fig. 2.1. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... ..................................................................................................................................... [3] (c) Suggest explanations for the distributions of the salmon and carp shown in Fig. 2.2. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... ..................................................................................................................................... [3] [Total: 9] © UCLES 2013 9693/04/O/N/13 [Turn over 8 Section B Answer all questions in this section. Write your answers on the lined pages provided. 3 (a) Define the following terms. (i) gene ............................................................................................................................. [1] (ii) genetic engineering ............................................................................................................................. [1] (iii) gene promoter .................................................................................................................................. ............................................................................................................................. [2] (b) Suggest how biotechnology could be used to reduce oil pollution on beaches and in the sea after a crude oil spillage. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... ..................................................................................................................................... [3] © UCLES 2013 9693/04/O/N/13 For Examiner’s Use 9 (c) Explain the ecological impacts that the oil industry can have on marine ecosystems. .......................................................................................................................................... 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[8] [Total: 15] © UCLES 2013 9693/04/O/N/13 [Turn over 10 4 (a) Suggest how a tourist resort could be developed in a coastal area in order to have a minimal impact on the natural environment. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... ..................................................................................................................................... [6] (b) Suggest and explain three methods that fishing regulatory bodies could use to ensure that cod fishing in the North Sea is sustainable. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... © UCLES 2013 9693/04/O/N/13 For Examiner’s Use 11 .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... ..................................................................................................................................... [6] (c) Suggest and explain the impacts that benthic trawling may have upon marine ecosystems. .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... .......................................................................................................................................... ..................................................................................................................................... [3] [Total: 15] © UCLES 2013 9693/04/O/N/13 For Examiner’s Use 12 BLANK PAGE Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2013 9693/04/O/N/13
