Peiicerdctezes Ah 000A Z Ba BOTSWANA EXAMINATIONS COUNCIL + Botswana General Certificate of Secondary Education CANDIDATE | NAME | CENTRE | | | canoiwate | NUMBER | NUMBER BIOLOGY 0572/03 Paper 3 OctoberiNovember 2016 ‘hour 15 minutes ‘Additional Materials; Answer Paper READ THESE INSTRUCTIONS FIRST ‘Write your Centre number, candidate number and name in the spaces provided at the top of this page, DO NOT WRITE IN ANY BARCODES. Section A Answer all questions. ‘Write your answers in the spaces provided on the question paper. Section B Answer both questions. \Write your answers on the separate answer paper provided Write your Centre number, candidate number and name on each shest of answer paper you use At the end of the examination fasten all sheets of answer paper to this question paper using the string provided. You may use a calculater. Do not use staples, paper clips, highlighters, glue or correction fluid The number of marks is given in brackets [] at the end of each question or part question. You are advised to spend no longer than 40 minutes on Section A. For Examiner's Use Section A Section B 6 | es CaS HRS EEE 7 TOTAL ‘This document consists of 7 printed pages and 1 blank page. eBec 2016 [Turn over &2 Section A Answer all questions in this section in the spaces provided. 1 Fig. 1.1 is a diagram of a plant cell showing structures J, K, and L as seen under a high power microscope. nucleus {a) Identify structures J, K and L and state their functions by completing Table 1.1 Identification of K and function of L have been done for you. Table 4.1 structure name function J K | cell membrane L | controls cell turgidity I (41 (b) Describe the relationship between the functions of the nucleus and ribosomes. ool2] (otal: 6] BEC 2016 osr2ev0N16 or Examiners Use3 Exominers 2. Fig. 2.1 is a graph showing the effect of carbon dioxide concentration on the rate of tee photosynthesis. rate of photosynthesis B c A carbon dioxide concentration Fig, 2.1 (a) Describe and explain the shape of the graph from point () AtoB {3] (i) Biot. (2) (b) Light energy is converted by chlorophyll into a form that plant cells can use. State the form into which light energy is converted {] [Total: 6] pec 2018 8 o572:09101N16 [Turn over4 3 Fig. 3.1 represents stages A, B, C and D that are involved in temperature regulation in humans. | w= Stage A Stage B receptors nx | MMUlse Lansmited FE detect changes in | 12 body _ control blood temperature mechanism temperature rises normal body temperature Stage D Stage C temperature temperature impulse transmitted [receptor in X arppe! control Je to body __| detects changes in mechanism blood temperature Fig. 3.4 (@) State one temperature control mechanism in stage B and two in stage D. (i) Stage B a ane eeord. Aff] Stage D: 1 Bane 2] (b) Identity structure X in Fig. 3.1 x 2 nian iv oe | (c) State the role played by receptors in the skin in temperature regulation a (d) Explain how negative feedback is involved in the control of blood glucose concentration. 51 [Total: 10] eBEC 2016 os7ansoiNit65 4 Table 4.1 shows some of the processes or features which are involved during breathing out in humans. (a) Complete Table 4.1, using the words listed to show changes that oocur during breathing out. Two have been done for you. A word may be used ones, more than onee or not at all relax contract. increases. © decreases © downwards upwards Table 4.1 process orfeature | change during breathing out | intercostal muscles rib cage moves diaphragm muscles diaphragm becomes more dome-shaped volume of lungs air pressure in lungs | | direction of airflow | outwards 8) (b) Describe two features of an alveolus and explain how each feature enables it to carry out its function efficiently (5) [Total: 10] exec 20s O572080NN15 [Turn over6 \ 6 Fig. 6.1 shows three possible coat colours of domestic rabbits. full coat colour Coat colour in domestic rabbits is controlled by three alleles, though only two can be present in a genotype. The alleles are represented as follows: C®, allele for full coat colour, the rebbit is grey in colour, C™, allele for Himalayan, rabbit has a white coat with black ears and feet, C®, allele for albino, rabbit is all white in colour. [ The allele for full coat colour C¥, is dominant to both the allele for Himalayan C*, and that for albino C*, The allele for an albino is recessive to both alleles for full coat colour and Himalayan, (a) With the aid of a genetic diagram below, determine the percentage chance of a full coat colour rabbit and a Himalayan rabbit having an albino offspring, parental phenotype: il coat colour x Himalayan parental genotype’ &-¢ ‘ ec — OOOO offspring genotype: offspring phenotype: : zl percentage chance of an albino offspring ...... % fo} (b) A farmer has a rabbit with full coat colour, but does not know its genotype. Suggest how the farmer may determine the genotype of the rabbit - (2) [Total: 7) - esec2016 2 osranai0Nie [Turn over7 Section B Answer both questions. Write your answers on the separate answer paper provided. 6 (a) Describe and explain the likely effect of throwing grass and other weeds into the water ina village dam. 6) (b) Describe how nitrogen in the atmosphere becomes part of animal tissue (91 [Total: 15] 7 Discuss the role of micro-organisms in production of (a) madila (sour milk) [4] (b) single cell protein is) {c}_ biogas and 3] (d)_ pest resistant crop plant. (5) [Total: 15] BEC 2016 a 0572080116BLANK PAGE Tid pany owned WalaraT OIE ‘reasonable efor hes been made by the publsher (BEC) to tase copyright Publisher wl be pleased to make amends athe earestposibe oppor. ‘by convTaN @ eluded has bean sought and GeWel Whee FoRBeEvey holders, but eny ems requing Clearance have unwttegly been inlude, Pe © BEC 2018, 0572/0a/0rNI16