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GCE JAN 2007 : (AS 3) Practical Processes

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Centre Number 71 Candidate Number ADVANCED SUBSIDIARY (AS) General Certificate of Education January 2007 Biology assessing Module 3A: Practical Processes ASB31 Assessment Unit AS 3A [ASB31] WEDNESDAY 24 JANUARY, MORNING TIME 1 hour INSTRUCTIONS TO CANDIDATES Write your Centre Number and Candidate Number in the spaces provided at the top of this page. Write your answers in the spaces provided in this question paper. Answer all five questions. You are provided with Photograph 3.2 for use with Question 2 in this paper. Do not write your answers on this photograph. INFORMATION FOR CANDIDATES The total mark for this paper is 50. Quality of written communication will be assessed in Questions 1(a), 3(a), 3(b) and 4(c), (denoted in the paper with an asterisk, *), and awarded a maximum of 2 marks. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. For Examiner s use only Question Number 1 2 3 4 5 QWC Total Marks ASB3AW7 1570 Marks 1 The mobility of many animals means that it is difficult to determine the size of an animal s population, though this may be estimated using the capture recapture technique. Examiner Only Marks Remark (a) Describe the steps that you would take to estimate the size of an animal population using the capture recapture technique. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [4] (b) State two assumptions that must be made when using this technique. 1. _______________________________________________________ _________________________________________________________ 2. _______________________________________________________ _______________________________________________________ [2] ASB3AW7 1570 2 [Turn over 2 Photograph 3.2 is a photomicrograph of a transverse section through the stem of a water lily (Nymphaea alba). The water lily is a hydrophytic plant. Examiner Only Marks Remark In the space below, draw a block diagram to show the tissue layers in the stem as shown in the photograph. Label the drawing to identify at least five structures. [9] ASB3AW7 1570 3 [Turn over 3 The J-tube apparatus, illustrated below, is used to analyse the composition of an air sample. plunger barrel of syringe of syringe Examiner Only Marks Remark capillary tube plastic tubing Source: Biology: A Functional Approach A Student s Manual (2nd Edition), M. B. V. Roberts and T. J. King, Nelson, 1987 (a) Describe how the J-tube apparatus is used to take up an air sample and the procedures undertaken, including precautions, prior to treatment with reagents. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [3] The air sample in the J-tube then receives two treatments. Treatment one involves the use of potassium hydroxide and is used to help determine how much carbon dioxide is in the air sample. (b) Describe how potassium hydroxide would be used to determine the percentage of carbon dioxide present in the air sample. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [3] ASB3AW7 1570 4 [Turn over Treatment two is used to help determine how much oxygen is present in the air sample. Examiner Only Marks Remark (c) (i) Which reagent would be used in this determination? ___________________________________________________ [1] (ii) Why must treatment two always follow treatment one? ______________________________________________________ ______________________________________________________ ___________________________________________________ [1] The table below represents the results of a J-tube analysis. Air sample Length of air sample/cm Original 20.9 After treatment 1 19.9 After treatment 2 16.7 (d) From the above results, calculate the percentage of oxygen in the air sample. Answer _____________ [2] ASB3AW7 1570 5 [Turn over 4 A lake was sampled for phytoplankton (microscopic green plants) and zooplankton (small herbivorous animals) over a 12-week period, starting in the spring. The results were expressed as grams of dry mass per square metre of lake, and are shown in the table below. Time/weeks Dry mass of phytoplankton/g m 2 1.7 0.12 2 2.2 0.13 4 3.5 0.15 6 5.4 0.23 8 9.4 0.37 10 5.6 0.82 12 2.4 Remark Dry mass of zooplankton/g m 2 0 Examiner Only Marks 0.60 (a) Plot the above results, using an appropriate graphical technique. You should use different scales for the phytoplankton and zooplankton data. (Use the graph paper opposite.) [8] (b) Identify the major trends in the results for both populations. _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [2] (c) Suggest explanations for the trends identified in (b). _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [3] ASB3AW7 1570 6 [Turn over ASB3AW7 1570 7 [Turn over 5 Ivy (Hedera sp.) has both sun leaves (high in the canopy and thus exposed to the sun) and shade leaves (low in the canopy and thus shaded). Sun leaves are, in general, thicker than shade leaves and so should photosynthesise faster, taking up carbon dioxide at a greater rate. A method of measuring CO2 uptake is to determine how long it takes for hydrogen carbonate/indicator solution to turn from orange to red. Examiner Only Marks Remark You are asked to devise a plan to test the hypothesis that sun leaves take up carbon dioxide at a faster rate than shade leaves. You are supplied with sun leaves and shade leaves of ivy hydrogen carbonate/indicator solution general school laboratory apparatus (a) Suggest an explanation for the formulation of the hypothesis stated above. _________________________________________________________ _________________________________________________________ _______________________________________________________ [1] (b) Identify the independent and dependent variables. Independent variable ______________________________________ _________________________________________________________ Dependent variable _______________________________________ _______________________________________________________ [1] (c) Identify one other major variable which it is important to control and state how this might be achieved. _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [2] ASB3AW7 1570 8 [Turn over (d) In the space below, draw diagrams to illustrate your plan for the investigation. Annotate your diagrams with appropriate notes relevant to your plan. Examiner Only Marks Remark [3] (e) Identify a major problem in measuring CO2 uptake which would affect the accuracy of the results. _________________________________________________________ _________________________________________________________ _______________________________________________________ [1] (f) Distinguish between the accuracy and the reliability of results. _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [2] Quality of written communication ASB3AW7 1570 9 [Turn over THIS IS THE END OF THE QUESTION PAPER ASB3AW7 1570 10 [Turn over S SB3AW7 1570 A 3/06 1600 9-033-1 [Turn2over 1 [Turn over GCE Biology Advanced Subsidiary (AS) Assessment Unit AS 3A Module 3A: Practical Processes January 2007 Photograph 3.2 (for use with Question 2) Source: Adapted from Dr Keith Wheeler/Science Photo Library ASB3AW7 1570.02 ASB31IN1

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Additional Info : : Gce Biology January 2007 Assessment Unit AS 3 Module 3A: Practical Processes
Tags : General Certificate of Education, A Level and AS Level, uk, council for the curriculum examinations and assessment, gce exam papers, gce a level and as level exam papers , gce past questions and answer, gce past question papers, ccea gce past papers, gce ccea past papers

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