2026 VJC H2 Biology Prelim P4 QP

VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION 2026 HIGHER 2 NAME : ……………………………………………………….………………. CT CLASS: ………………..……… BIOLOGY Paper 4 Practical 9477 / 04 26/08/2026 2 hours 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions. READ THESE INSTRUCTIONS FIRST Write your name and CT class on all the work you hand in. Give details of the practical shift and laboratory, where appropriate, in the boxes provided. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. At the end of the examination, fasten all your work securely together. The number of marks is given in bracket [ ] at the end of each question or part question. Shift Laboratory Question Marks 1 2 3 Total This document consists of 21 printed pages.

2 Answer all questions. 1 When potato cells are placed into different concentrations of sodium chloride solution, water moves between the sodium chloride solution and the potato cells. You will investigate the effect of different concentrations of sodium chloride solution on potato tissue. You will need to: • prepare different concentrations of sodium chloride solution, S • put potato tissue into the different concentrations of sodium chloride solution • record the distance the potato tissue bends • use your results to estimate the concentration of an unknown concentration of sodium chloride solution, U. You are provided with: • 6 pieces of potato tissue in a Petri dish labelled P • 10.0% sodium chloride solution in a container labelled S • unknown concentration of sodium chloride labelled U • distilled water labelled W. It is recommended that you wear suitable eye protection.

3 (a) You will need to prepare different concentrations of sodium chloride solution, using proportional dilution. You will need to prepare 50.0 cm3 of each concentration, using S and W. Table 1.1 shows how to make up two of the concentrations of sodium chloride solution you will use. Decide which other concentrations of sodium chloride solution you will use. (i) Complete Table 1.1 to show how you will prepare the concentrations of sodium chloride solutions you will use. Table 1.1 percentage concentration of sodium chloride volume of S / cm3 volume of W / cm3 10.0 50.0 0.0 0.0 0.0 50.0 [2] Proceed as follows. 1 Prepare the concentrations of sodium chloride solution as shown in Table 1. 1, in the containers provided. Mix well. 2 Label the Petri dishes with the concentrations of sodium chloride solution prepared in step 1. 3 Label another Petri dish U. 4 Cut each piece of potato tissues to a length of 6.0 cm.

4 5 Put a piece of potato tissue into each of the Petri dishes you have labelled. You are to determine a suitable volume of the sodium chloride solution prepared in step 1 to add to each Petri dish containing a piece of potato tissue, as shown in Fig. 1.1. On Fig. 1.1, draw a line to indicate the level of solution you would use. Fig. 1.1 (ii) State the volume of sodium chloride solution you will use. volume ................................. cm3 [1] (iii) Explain why you chose this volume of sodium chloride solution. …………………………………………………………………………………………………... …………………………………………………………………………………………………... ………………………………………………………………………………………….……….. …………………………………………………………………………………………………... …………………………………………………………………………………………….…. [2] 6 Put the volume of each concentration of sodium chloride solution you have decided in (a)(ii) into the appropriately labelled Petri dish. 7 Repeat step 6 using U. 8 Leave the pieces of potato tissue in the sodium chloride solutions for 20 minutes. While you are waiting, use your time to continue with Question 1. You will use graph paper to measure how far the pieces of potato tissue bend after being left for 20 minutes in the sodium chloride solutions.

5 Fig. 1.2 shows how you will prepare the graph paper, as described in step 9 and step 10. Fig. 1.2 9 On the graph paper provided, draw two lines at right angles to each other, as shown in Fig. 1.2. Each line should be 6.0 cm long. Draw a mark on the vertical line 3.0 cm below where the vertical line meets the horizontal line, as shown in Fig. 1.2. 10 On the same piece of graph paper repeat step 9 for each of the other concentrations of sodium chloride solution and for U. 11 After 20 minutes (step 8) remove the piece of potato tissue from the 10.0% sodium chloride solution and put it onto a paper towel to remove the excess liquid.

6 12 Put the piece of potato tissue on the vertical line of the graph paper, as shown in Fig. 1.3. Fig. 1.3 13 Put your finger on the middle of the potato tissue at the 3.0 cm mark and press firmly, as shown in Fig. 1.4. Fig. 1.4

7 14 Hold the potato tissue firmly in this position. Move the top of the potato tissue, as shown in Fig. 1.5, until there is some resistance. Fig. 1.5 15 Mark the position of the top of the potato tissue on the graph paper, as shown in Fig. 1.6. Fig. 1.6 16 Remove the potato tissue and put it in the container labelled For waste. 17 Measure the distance between the mark and the horizontal line on the graph paper, as shown in Fig. 1.6. 18 Record your result in (a)(iv). 19 Repeat step 11 to step 18 using the potato tissue from the other concentrations of sodium chloride solution. 20 Repeat step 11 to step 17 using the potato tissue from U. Record your result for U in (a)(v).

8 (iv) Record your results in an appropriate table. [3] (v) Record the result for U. Use your results in (a)(i v) to estimate the concentration of sodium chloride in U. result for U ............................................ estimate ....................................... [1] (vi) Explain the trend shown by your results in terms of water potential. …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... ………………………………………………………………………………………….……….. …………………………………………………………………………………………………... …………………………………………………………………………………………….…. [3]

9 (vii) Suggest how you could make improvement to the procedure so that a more accurate estimate of the concentration of sodium chloride in U can be obtained. ………………………………………………………………………………………….……….. …………………………………………………………………………………………………... …………………………………………………………………………………………….…. [1] (viii) Identify one source of error in this investigation. Explain how this error could affect your results. ………………………………………………………………………………………….……….. …………………………………………………………………………………………………... ………………………………………………………………………………………….……….. …………………………………………………………………………………………………... …………………………………………………………………………………………….…. [2]

10 (b) A student investigated the effect of placing pieces of tissue from a potato in sucrose solutions of different concentrations. At the start, each sample of potato tissue was weighed, and the initial mass was recorded. Then each sample of potato tissue was placed into a different concentration of sucrose solution. After a set time the potato tissue was removed, and the final mass of the potato tissue was recorded. The percentage change in mass for each sample of potato tissue was calculated. The results of the student’s investigation are shown in Table 1.2. Note: the percentage change in mass is shown to the nearest 0.5%. Table 1.2