EXAMINATIONS COUNCIL OF SWAZILAND in collaboration with UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS Swaziland General Certificate of Secondary Education *3676304470* BIOLOGY 6884/03 Paper 3 Extended October/November 2011 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. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions. Write your answers in the spaces provided on the question paper. You may use a calculator. 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. 1 2 3 4 5 6 7 8 9 10 Total This document consists of 14 printed pages and 2 blank pages. DC (LEO/SW) 35042/4 [Turn over
1 (a) Human beings are classified as Homo sapiens. 2 (i) Name this system of classifying organisms. State the genus name for human beings. (b) Fig.1.1 shows a microscopic organism that was found in a water sample. Fig. 1.1 (i) Name the group to which the microscopic organism shown in Fig. 1.1 belongs. Suggest a feature of the microscopic organism that makes it adapted to live in water. [Total: 4]
2 (a) Fig. 2.1 shows a diagram of a plant cell. The diagram is not to scale. 3 Fig. 2.1 (i) Name the type of plant cell in Fig. 2.1. State two structural features present in the cell in Fig. 2.1 that are not found in a liver cell. 1... 2... [2] (b) Label on Fig. 2.1 the parts that have the following functions using the given letter and a labelling line. A contains chromosomes B watery liquid that causes cell turgidity C releases energy from respiration [3] (c) Root hair cells help plants to absorb water and mineral ions from the soil. Name and describe the processes involved in the absorption of water and the uptake of low concentration mineral ions by root hair cells. (i) water...[3] mineral ions...[3] [Total: 12] [Turn over
3 (a) Micro-organisms and fermenters are used to manufacture enzymes for use in biological washing powders. 4 Fig. 3.1 shows a large sterile vessel called a fermenter. stirrer Fig. 3.1 (i) State the purpose of the stirrer. Explain why the large vessel should be sterile during the process....[2] (iii) Name two micro-organisms that can be used to manufacture enzymes....[2] (iv) Suggest how the biological washing powder is more effective than ordinary detergent....[3]
(b) Fig. 3.2 shows food items produced by the use of enzymes. 5 bread beer Fig. 3.2 (i) Name the micro-organism used in the manufacture of bread.... [1] Describe and explain how enzymes are used in the manufacture of beer....[3] [Total: 12] [Turn over
4 (a) A water plant releases bubbles into the water as a result of photosynthesis. Therefore the rate of photosynthesis can be measured using the number of bubbles produced per minute. 6 Table 4.1 shows results obtained during an experiment investigating the effect of light intensity on the rate of photosynthesis. Table 4.1 light intensity (arbitrary units) number of bubbles per minute 2 75 4 150 6 225 8 275 10 300 12 300 (i) Plot the data shown in Table 4.1 on the grid below. [3]
(iii) (iv) (b) (i) Estimate the light intensity that will produce 200 bubbles per minute. 7 Using your graph, describe the relationship between the rate of photosynthesis and light intensity....[2] Explain why the rate of photosynthesis is the same at 10 and 12 light units....[2] Using symbols, state the equation of photosynthesis....[2] In many plants some of the sugar formed in photosynthesis is converted to starch for storage. Explain the advantage of storing starch rather than sugar....[2] [Total: 12] [Turn over
5 Fig. 5.1 shows the structure of a villus in the ileum. 8 D (a) Name the part labelled D on Fig. 5.1. Fig. 5.1...[1] (b) Explain two ways in which villi are adapted for nutrient absorption. 1...... 2...... [4] (c) Name one nutrient that is found in the blood capillaries....[1] [Total: 6]
6 (a) The apparatus in Fig. 6.1 is used to find out where most water is lost in plants. 9 oil layer oil layer water water E F Fig. 6.1 Evidence of water lost will be the formation of water droplets inside the bell jar. After four hours, one of the bell jars had more water droplets than the other. (i) Explain why one of the bell jars had more water droplets than the other....[3] State the purpose of the oil on the surface of the water. (iii) Explain the mechanism of water movement up the stem in a plant....[3] [Total: 7] [Turn over
7 (a) Name the process by which the body keeps its internal environment constant. 10...[1] (b) Two people who had not eaten for 12 hours were given equal amounts of glucose solution to drink. Their blood sugar levels were checked regularly for two hours. Fig. 7.1 below shows the results of the glucose tests for the two people. glucose high person H person I glucose low 0 1 2 time / hours T 0 T 1 Fig. 7.1 (i) Describe what happens to the glucose level of persons H and I between time T 0 and T 1. Explain the differences observed in the glucose level of H and I after time T 1....[4]
11 (c) Physical activity is important for good human health. Explain why the breathing rate increases during physical activity................[3] [Total: 9] [Turn over
8 (a) Fig. 8.1 shows a part of a flower. 12 pollen grain J Fig. 8.1 (i) Name the part labelled J on the diagram. Outline the sequence of events from the time the pollen grain falls onto the stigma to seed formation....[4] (iii) State one advantage of cross-pollination. [Total: 6]
9 Sickle cell anaemia is caused by a sudden spontaneous genetic change. This results in the red blood cells assuming a sickle shape. The allele for sickle cells (H s ) is recessive to the allele for normal cells (H n ). 13 (a) State the term used to describe such a sudden spontaneous genetic change....[1] (b) State the genotype of a person who does not exhibit the symptoms of sickle cell anaemia but who carries the sickle cell gene using the notation given in the stem....[1] (c) Draw a genetic diagram to show the genotypic ratios of offspring of parents who are both heterozygous for sickle cell. [5] [Total: 7] [Turn over
10 Fig. 10.1 shows the nitrogen cycle. 14 nitrogen in the air nitrogen in plants nitrogen in animals denitrifying bacteria absorption decomposers N nitrates in soil M ammonia in organic matter Fig. 10.1 (a) Name the nitrogen-containing compound found in both plants and animals....[1] (b) State the process that is taking place at M....[1] (c) Describe the process or processes taking place at N.............[3] [Total: 5]
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