1 Centre Number Candidate Number For Examiner's Use Candidate Name NAMIBIA SENIOR SECONDARY CERTIFICATE 4322/3 BIOLOGY ORDINARY LEVEL PAPER 3 Applied Practical Skills 1 hour 30 minutes Marks: 60 2008 BOOKLET Additional materials: rulers calculators INSTRUCTIONS AND INFORMATION TO CANDIDATES • • • • • Write your Centre Number, Candidate Number and Name in the spaces at the top of this page. Write in dark blue or black pen in the spaces provided on the question 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 the margin For Examiner's Use. • • Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner's Use Section A 1 2 3 4 5 Total This document consists of 12 printed pages. Republic of Namibia © MoE/DNEA MINISTRY OF EDUCATION 4322/3/08 [Turn over [Turn over 2 1 5cm3 starch solution was placed in four test tubes labelled A, B, C and D as shown in Fig. 1.1. 2cm3 saliva was placed in each of tubes B and C. B A C D 5 cm3 starch solution 2 cm3 saliva Fig. 1.1 The tubes were shaken to mix the contents and left for 15 minutes. After 15 minutes, three drops of iodine solution were added to each of test tubes A and B. 3cm3 of Benedict's solution were added to test tubes C and D. Test tubes C and D were placed in a boiling water bath for 5 minutes. Some of the results are shown in Table 1.1 Table 1.1 tube reagent result A iodine solution B iodine solution yellow brown C Benedict's solution orange precipitate D Benedict's solution 4322/3/08 For Examiner's Use 3 (a) State which substance is tested for with Benedict's solution. .............................................................................................................................. (b) Complete the results for test tubes A and D in table 1.1. [1] [2] (c) Explain the result of test tube B. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. [2] (d) The test tubes were kept at 20°C during the time of the experiment. Predict how the time taken for the colour change in B and C would change if the test tubes had been kept at 30°C. Prediction .............................................................................................................. Explanation ........................................................................................................... .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. [3] (e) Describe how you would carry out a test to compare the vitamin C content of two fruit juice samples. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. 4322/3/08 [5] [13] [Turn over For Examiner's Use 4 2 For Examiner's Use Fig. 2.1 shows a potometer which is used to measure the rate of water uptake by a shoot. transpiring shoot, drawing up water from the potometer reservoir containing water air/water meniscus airtight seal screw clip capillary tube water Fig. 2.1 (a) (i) Explain two precautions that must be taken when setting up this experiment. Precaution 1 ................................................................................................... Explanation .................................................................................................... ....................................................................................................................... ....................................................................................................................... Precaution 2 ................................................................................................... Explanation .................................................................................................... ....................................................................................................................... ....................................................................................................................... [4] (ii) As the water is taken up by the shoot, the meniscus moves towards the left. Explain how you would move the meniscus back to its original position. ....................................................................................................................... ....................................................................................................................... 4322/3/08 [1] 5 (b) Four sets of apparatus were placed in each of the following laboratory conditions: For Examiner's Use E in classroom conditions (simulates shaded, calm conditions) F in front of a heater G set under a clear plastic bag in which water has been sprinkled H set in front of a fan 15 minutes were allowed for each shoot to adjust to these conditions. The distance moved by the meniscus was then recorded at 15 minute intervals. The experiments were repeated three times. Table 2.1 shows the results. Table. 2.1 conditions distance moved by meniscus every 15 minutes/mm 1 2 3 rate = average E in classroom 2.8 2.8 2.6 2.7 0.18 F in front of heater 5.0 6.2 5.3 5.5 0.37 G in plastic bag 1.9 0.8 0.9 H fan 7.1 6.9 8.2 (i) average distance/m m time/min Complete the table by calculating the missing values. [2] (ii) Suggest which environmental condition is simulated by the fan. ....................................................................................................................... [1] (iii) Describe the differences in water taken up by the shoots in conditions B and C. ....................................................................................................................... ....................................................................................................................... [1] (iv) Explain the differences you have described in (iii). ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... 4322/3/08 [3] [12] [Turn over 6 3 Fig. 3.1 shows an apparatus to demonstrate breathing in humans. For Examiner's Use glass y-tube stopper balloon bell jar plastic sheet rubber band Fig. 3.1 (a) Name the part of the human ventilation system that is represented by each of the following parts of the apparatus. (i) glass tube ...................................................................................................... (ii) balloons ......................................................................................................... (iii) bell jar ............................................................................................................ (iv) plastic sheet................................................................................................... (b) (i) Complete the diagrams in Fig. 3.2, to show what happens to the balloons when the plastic sheet is pulled down (A) and when the plastic sheet is pushed up (B). A B plastic sheet pushed up pulled down Fig. 3.2 4322/3/08 [4] [2] 7 (ii) Explain how air moves into the lungs during inhalation. For Examiner's Use ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... [5] (c) Compare the ways in which this apparatus in Fig. 3.1 differs from the human ventilation system. 1 ............................................................................................................................ .............................................................................................................................. 2 ............................................................................................................................ .............................................................................................................................. 4322/3/08 [2] [13] [Turn over 8 4 Fig. 4.1 shows a young oat seedling. When an oat grain germinates, its shoot is enclosed in a sheath of tissue known as a coleoptile. coleoptile food store young root Fig. 4.1 The coleoptiles of germinated oat grains will continue to grow if placed in a sucrose solution. Different concentrations of auxins can be added to the sucrose solution. The effect of the auxins on the growth of shoots and roots are shown in Table 4.1. Table 4.1 auxin concentration/ arbitrary units % growth stimulation in shoots (coleoptile) % growth stimulation in roots 1 5 2 2 15 20 3 25 5 4 45 0 5 65 0 6 95 0 7 75 0 4322/3/08 For Examiner's Use 9 (a) (i) Plot a graph to show the results for the shoots in Table 4.1. [5] (ii) Describe the results for the effect of auxin on the % growth stimulation of the shoots. ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... [2] (iii) With reference to Table 4.1, compare the results of the shoot and the root at an auxin concentration of 6 arbitrary units. ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... 4322/3/08 [2] [Turn over For Examiner's Use 10 (b) State two effects of auxins on the cells at the tip of a shoot. For Examiner's Use 1 ............................................................................................................................ .............................................................................................................................. 2 ............................................................................................................................ .............................................................................................................................. 4322/3/08 [2] [11] 11 5 Fig. 5.1 shows the front view of a human eye. X For Examiner's Use Y Fig. 5.1 (a) Make a large, labelled drawing of this eye. 4322/3/08 [5] [Turn over 12 (b) The photograph in Fig. 5.1 shows the eye magnified x1.5. For Examiner's Use Measure the distance between points X and Y on Fig. 5.1. Use this measurement to calculate the magnification of your drawing, allowing for the x1.5 magnification of the photograph. Show your working. Distance between X and Y on photograph: .......................................................... Distance between X and Y on your drawing: ........................................................ Magnification of your drawing: .............................................................................. [4] (c) Fig. 5.2 shows front views of a cat’s eye at 3 p.m. and at 3 a.m. A B Fig. 5.2 (i) State which one, A or B, shows the appearance of the cat’s eye at 3 a.m. ....................................................................................................................... (ii) Explain your answer. ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... ....................................................................................................................... [2] [11] [TOTAL: 60] 4322/3/08
