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GCE MAY 2007 : (A2 1) Co-ordination, Biochemistry and Environment

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Centre Number 71 Candidate Number ADVANCED General Certificate of Education 2007 Biology assessing Module 4: Co-ordination, Biochemistry and Environment A2B11 Assessment Unit A2 1 [A2B11] MONDAY 14 MAY, AFTERNOON TIME 1 hour 30 minutes. 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 nine questions. You are provided with Photograph 4.8 for use with Question 8 in this paper. Do not write your answers on this photograph. For Examiner s use only Question Number 1 2 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA 3 INFORMATION FOR CANDIDATES The total mark for this paper is 75. Section A carries 60 marks. Section B carries 15 marks. You should spend approximately 20 minutes on Section B. You are expected to answer Section B in continuous prose. Quality of written communication will be assessed in Section B. Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question. A2B1S7 2607 4 5 6 7 8 9 Total Marks Marks 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA BLANK PAGE A2B1S7 2607 2 [Turn over Section A Examiner Only Marks 1 Remark Antidiuretic hormone (ADH) plays a central role in osmoregulation by influencing the functioning of the kidneys. (a) Describe the effect of ADH on the functioning of the kidneys. _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [2] (b) Anaesthetics inhibit ADH secretion. Suggest what effect anaesthetics will have on urine production. _________________________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA _______________________________________________________ [1] A2B1S7 2607 3 [Turn over 2 Antibodies are proteins produced and secreted by plasma cells in response to the presence of foreign antigens. Examiner Only Marks Remark (a) Describe how plasma cells are produced in response to a foreign antigen. _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [3] The diagram below represents a plasma cell as viewed by an electron microscope. 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA Source: New Perspectives in Advanced Biology, Martin Hanson, Hodder and Stoughton, 1999 (b) Using the information available in the diagram, describe two adaptations of plasma cells for the production of large quantities of antibodies. 1. _______________________________________________________ _________________________________________________________ 2. _______________________________________________________ _______________________________________________________ [2] A2B1S7 2607 4 [Turn over 3 The commercially produced herbicide, Paraquat, affects the light-dependent stage of photosynthesis, specifically interfering with the chloroplast s ability to produce NADPH. Examiner Only Marks Remark (a) (i) State the location of NADPH production in the chloroplast. ___________________________________________________ [1] (ii) State two other products of the light-dependent stage. 1. _____________________ 2. _____________________ [1] (b) Outline the role of NADPH in the subsequent light-independent stage of photosynthesis. _________________________________________________________ _______________________________________________________ [1] (c) Eventually, respiration also stops in Paraquat-treated plants and so these plants die. Suggest a sequence of events that would result in respiration stopping. _________________________________________________________ _________________________________________________________ _________________________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA _______________________________________________________ [2] A2B1S7 2607 5 [Turn over 4 The metabolism of endotherms (homoiotherms) and ectotherms (poikilotherms) is influenced by the temperature of the external environment, though in different ways. The graph below shows how the metabolic rate of both groups is influenced by changes in environmental temperature. Examiner Only Marks Remark Metabolic rate/arbitrary units 7 6 5 4 3 endotherm ectotherm 2 1 0 0 10 20 30 40 Environmental temperature/ C (a) Explain why the metabolic rate of an endotherm increases as the environmental temperature falls below 20 C. _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [2] (b) Suggest explanations for the metabolic rate of an endotherm remaining steady between 25 C and 40 C. _________________________________________________________ _________________________________________________________ _______________________________________________________ [2] 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA _________________________________________________________ A2B1S7 2607 6 [Turn over (c) Explain why the metabolic rate of an ectotherm increases as the environmental temperature increases. Examiner Only Marks Remark _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [2] (d) At a low temperature, the metabolic rate of an endotherm is many times that of an ectotherm. Suggest one advantage and one disadvantage of this. Advantage ________________________________________________ _________________________________________________________ Disadvantage ______________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA _______________________________________________________ [2] A2B1S7 2607 7 [Turn over 5 The flow diagram below shows four steps (labelled 1 to 4) in glycolysis. Examiner Only Marks Remark Glucose 2 ATP Step 1 2 ADP Fructose bisphosphate Step 2 Triose phosphate NAD+ ADP + Pi Triose phosphate NAD+ ADP + Pi Step 3 NADH (+H+) NADH (+H+) ATP Glycerate bisphosphate ADP ATP Glycerate bisphosphate ADP Step 4 ATP ATP Pyruvate Pyruvate (a) State the net gain of ATP from one molecule of glucose within glycolysis. _______________________________________________________ [1] (b) Explain why glucose is not normally limiting within a muscle cell. _________________________________________________________ _______________________________________________________ [1] (c) NAD+ is required for step 3 and is regenerated by hydrogen being removed from NADH. Explain how hydrogen is removed from NADH when (i) oxygen is not limiting ____________________________________ 3 27.7.06EA ______________________________________________________ ______________________________________________________ 2 30.5.06BP (ii) oxygen is limiting _______________________________________ 1 11.3.06EA ___________________________________________________ [2] ______________________________________________________ ______________________________________________________ ___________________________________________________ [2] A2B1S7 2607 8 [Turn over (d) The intermediates of metabolic pathways may be determined by investigating the effect of specific inhibitors. Iodoethanoate inhibits the dehydrogenase enzyme that catalyses step 3 in glycolysis. What would be the effect of iodoethanoate on the levels of the intermediates of glycolysis? Examiner Only Marks Remark _________________________________________________________ _________________________________________________________ _________________________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA _______________________________________________________ [2] A2B1S7 2607 9 [Turn over 6 The diagram below represents a synapse between two adjacent nerve cells. The diagram has been simplified into three regions labelled 1, 2 and 3. Examiner Only Marks Remark direction of impulse 1 2 3 The table below contains information on three neurotoxins produced by three living organisms and their effect on the nervous system of their victims. (a) Complete the table by inserting the appropriate numbers from the diagram above to indicate the region of the synapse affected by each neurotoxin. Living organism How the nervous system is affected Agatoxin Funnel web spider Blocks calcium channels Alphabungarotoxin Krait (snake) Blocks acetylcholine receptor Holocyclotoxin Australian paralysis tick Inhibits release of acetylcholine Neurotoxin Region of synapse affected [3] 3 27.7.06EA Tetrodotoxin is another form of neurotoxin produced by the blue ring octopus and the Puffer fish. Tetrodotoxin blocks the sodium channels on the membrane of the victim s nerve cells inhibiting the generation of impulses. Its mode of action is illustrated by the diagram below. tetrodotoxin sodium ion 2 30.5.06BP 1 11.3.06EA sodium channel sodium channel membrane transmembrane protein A2B1S7 2607 10 [Turn over (b) Suggest what effect this blockage would have on the normal functioning of the nerve cell. Examiner Only Marks Remark _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _______________________________________________________ [3] The Puffer fish is considered a food delicacy in countries such as Japan. Careful butchery of the fish, and cooking, reduces and destroys the tetrodotoxin, rendering the fish safe to eat. (c) (i) Suggest how cooking can render the tetrodotoxin harmless to the consumer. _____________________________________________________ _____________________________________________________ _____________________________________________________ ___________________________________________________ [2] (ii) Suggest how the puffer fish itself is not affected by its own tetrodotoxin. _____________________________________________________ Neuroscientists are now considering using tetrodotoxin as a potential nonaddictive pain killer for patients suffering from chronic pain. (d) What type of nerve cell would be targeted by such tetrodotoxin treatment? _______________________________________________________ [1] 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA ___________________________________________________ [1] A2B1S7 2607 11 [Turn over 7 (a) (i) Name the nitrogen-containing ion that is released as a result of the decomposition of dead organisms. Examiner Only Marks Remark ___________________________________________________ [1] (ii) Name the nitrogen-containing ion that is absorbed by plant roots. ___________________________________________________ [1] (iii) Name the group of soil bacteria which converts the nitrogencontaining ion released by decomposers to the nitrogen-containing ion absorbed by plants. ___________________________________________________ [1] (b) The availability of an ion in the soil is directly related to its solubility, which in turn depends on soil pH. The graph below shows the effect of pH on the solubility of four mineral ions. (The thickness of the horizontal bands represents the solubility of each mineral ion.) The three mineral ions most required by plants are those containing nitrogen (N), phosphorus (P) and potassium (K). solubility of mineral ions N- containing ion P- containing ion K ion Aluminium ion 4 4.5 5 5.5 6 6.5 7 pH 7.5 8 8.5 9 9.5 10 (i) Using the information above, deduce the pH range that would be optimal for plant growth. Explain your answer. 2 30.5.06BP 3 27.7.06EA Source: Adapted from Applied Ecology, Geoff Hayward, Nelson, 1992 _____________________________________________________ 1 11.3.06EA _____________________________________________________ ___________________________________________________ [2] A2B1S7 2607 12 [Turn over (ii) Using the information in the graph, explain why aluminium is readily leached out of the soil when the rainfall is highly acidic. Examiner Only Marks Remark _____________________________________________________ ___________________________________________________ [1] (iii) Outline the consequences of high concentrations of aluminium entering rivers and lakes. _____________________________________________________ _____________________________________________________ _____________________________________________________ ___________________________________________________ [2] (iv) Outline what causes rainfall to be highly acidic. _____________________________________________________ _____________________________________________________ _____________________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA ___________________________________________________ [2] A2B1S7 2607 13 [Turn over 8 (a) Photograph 4.8 is a transmission electronmicrograph (TEM) showing part of a striated muscle fibre. (Colour has been provided by computer enhancement.) Examiner Only Marks Remark (i) Identify the features labelled A to D. A ___________________________________ B ___________________________________ C ___________________________________ D ___________________________________ [4] (ii) Explain the role of the feature labelled A in muscle contraction. _____________________________________________________ ___________________________________________________ [1] (b) The diagram shows stages of the sliding filament theory of muscle contraction. Stage 1 actin filament myosin head Stage 4 Stage 2 3 27.7.06EA myosin filament cross-bridge formation Stage 3 1 11.3.06EA 2 30.5.06BP movement of actin Source: Adapted from Biological Science 2, 3rd edition, Taylor, Green and Stout (ed. Soper), Cambridge 1997 A2B1S7 2607 14 [Turn over (i) Describe the sequence of events that leads to each of the following stages shown in the diagram. Examiner Only Marks Remark Stage 2 _____________________________________________ _____________________________________________________ ___________________________________________________ Stage 3 _____________________________________________ _____________________________________________________ ___________________________________________________ Stage 4 _____________________________________________ _____________________________________________________ _________________________________________________ [3] 3 27.7.06EA (ii) During maximal muscle contraction, the distance between the Z lines is shortened to 50% of the resting length of 2 m. Each rotation of a myosin cross bridge pulls the actin filament a distance of 10 nm. Calculate the number of rotations of the cross bridges to bring about a maximal contraction. (Show your working.) 1 11.3.06EA 2 30.5.06BP Answer _________________ [3] A2B1S7 2607 15 [Turn over Section B Examiner Only Marks Remark In this section you are expected to answer in continuous prose, supported, where appropriate, by diagrams. You are reminded that up to two marks in this question are awarded for the quality of written communication. [2] 9 Give an account of the role of photoreceptor pigments in the mammalian eye and in the control of flowering in plants. [13] ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ 2 30.5.06BP ____________________________________________________________ ____________________________________________________________ 1 11.3.06EA 3 27.7.06EA ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ A2B1S7 2607 16 [Turn over Examiner Only ____________________________________________________________ Marks Remark ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ A2B1S7 2607 17 [Turn over Examiner Only ____________________________________________________________ Marks Remark ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ A2B1S7 2607 18 [Turn over Examiner Only ____________________________________________________________ Marks Remark ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ 1 11.3.06EA 2 30.5.06BP 3 27.7.06EA ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ A2B1S7 2607 19 [Turn over 3 27.7.06EA 2 30.5.06BP 1 11.3.06EA Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright holders may have been unsuccessful and CCEA will be happy to rectify any omissions of acknowledgement in future if notified. S 5/05 -051-1 A2B1S7 72607 20 [Turn over 2 5.8.05BP 3 23.9.05EA A B Z line C Z line D GCE Biology Advanced Assessment Unit A2 1 Module 4: Co-ordination, Biochemistry and Environment Summer 2007 Photograph 4.8 (for use with Question 8) 1 27.5.05BP A2B1S7 2607.02 A2B11IN1 Source: Biology Media/Science Photo Library

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Additional Info : Gce Biology May 2007 Assessment Unit A2 1 - Module 4: Co-ordination, Biochemistry and Environment
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