Temasek Sec 2024 Prelim 4E BIO P3 QP

1 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. Name: Index Number: Class: __________ TEMASEK SECONDARY SCHOOL O Level Preliminary Examination 2024 Secondary 4 Express BIOLOGY 6093/03 Paper 3 Practical Test 1 hour 50 minutes Candidates answer on the Question Paper. Additional Material: Nil READ THESE INSTRUCTIONS FIRST Do not open the booklet until you are told to do so. You are required to submit this booklet at the end of the examination. Write your name, index number and 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/2B pencil for any diagrams or graphs. 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 brackets [ ] at the end of each question or part question. Shift Laboratory For Examiner’s Use 1 2 Total /40 This document consists of 12 printed pages.

2 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. 1 You are advised to read the whole question before you start. Plants transport water up along xylem vessels. In this experiment, you are going to compare the upward movement of water in the celery and in a piece of blackboard chalk. You are provided with: • 2 pieces of blackboard chalk • 2 petri dishes • 1 pin • 1 stopwatch • 1 plastic dropper • 1 “stick” of celery stalk (10cm long) • Paper towels • knife • white tile • ruler (15cm) • 60cm3 of coloured water (in beaker) Part 1 Step 1 Pour coloured water into two petri dishes until each is half full. Step 2 Cut the celery stalk into two equal lengths. Stand one half of the stalk vertically onto a dish of coloured water. Step 3 Stand one piece of chalk vertically on the other dish of coloured water as shown in Fig.1.1. Fig.1.1 Step 4 Take it out immediately and make a mark (dot) wit h the pin on the level of coloured water.

3 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. Step 5 Put the chalk back and immediately start the stopwatch. Step 6 At 1 minute, with the chalk still standing in the petri dish, use the pin to make a mark (dot) on the level of the coloured water. Step 7 Continue to record the level of coloured water at 1 minute interval for a duration of 6 minutes. Step 8 Remove the chalk from the dish and dab the base of the chalk onto a piece of paper towel. M easure the height of the coloured water markings made on the chalk. Record your answers to the nearest mm. Step 9 Repeat step 3 to step 8. Step 10 Calculate the average height of markings for each of the time intervals. (a) Present all your results in a table in the space provided. [4]

4 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. (b) Use the grid provided to plot a graph of average height of the coloured water marking against time. [4] (c) Determine the rate of uptake of coloured water at t = 1.5 min. Show on the graph how you determine the rate. Answer: ……………………. [2]

5 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. Part 2 (d) Based on what you observed in the chalk, state one difference in the movement of coloured water up the chalk and the stick of celery. ……………………………………………………………………………………………… ………………………………………………………………………………………….. [1] (e) Identity two key sources of error in the experiment with the chalk and explain how it affects the results. Source of error 1 …………………………………………………..………………...………….. Explanation ……….……………………………………………………………………………… ………………………………………………………………………………………………….. [2] Source of error 2 ………………………………………………………………………………… Explanation ……….……………………………………………………………………………… ………………………………………………………………………………………………….. [2] Step 11 Remove the celery stalk from the dish and dab the base of the celery onto a piece of paper towel. Observe the top surface of the celery stalk. Use the knife to m ake a vertical cut down the celery to expose some of the stained tissue according to Fig.1.2. Fig. 1.2 Step 12 Break the chalk to expose the transverse section of the stained portion.

6 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. (f) Describe one advantage of repeating the investigation. ……………………………………………………………………………………………... ………………………………………………………………………………………..... [1] (g) A student is provided with the apparatus shown in Fig. 1.3. Fig.1.3

7 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. Describe how this apparatus, could be used to compare the rate of transpiration under different conditions of air movement. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ..…………………………………………………………………………………………. [5] [Total: 21]

8 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. 2 You are provided with a small mirror to use for studying one of your eyes. (a) (i) Make a large labelled drawing of one of your eyes in the space below. Include the structures immediately surrounding your eyes that provide it with protection. [5] (ii) Calculate the magnification of your drawing. Show your working. Magnification = ……………… [2]

9 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. (b) While looking at his left eye with a mirror, a student covered his right eye with his hand. After 10 seconds, the student removed his hand. The student made simple diagrams of part of his left eye which are shown in Fig.2.1. Fig. 2.1 (i) Describe what happened to the left eye when the right eye was covered and then uncovered. ……………………………………………………………………………………... ……………………………………………………………………………………... ………………………………………………………………………………...…[2] (ii) Explain what happened inside the left eye to bring about the changes you have described. ……………………………………………………………………………………... ……………………………………………………………………………………... ……………………………………………………………………………………... ………………………………………………………………………………...…[2]

10 No part of this paper is to be reproduced without the prior approval of the Principal of Temasek Secondary School. (c) Squid have eyes that are very similar