YCKSS Pure Biology Prelim 2024 Paper 2

Name: Index Number: Class: YIO CHU KANG SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY FOUR EXPRESS BIOLOGY 6093/02 Paper 2 1 hour 45 minutes 9 September 2024 (Monday) No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, index number and class on the cover page. Write in dark blue or black ink. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions in the spaces provided. Section B Answer one question in the spaces provided. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A / 70 Section B / 10 Total / 80 Setter: Mr Wong Mingwei This document consists of 24 printed pages.

2 4E PRELIMINARY EXAM 2024 6093/02 SECTION A Answer all questions in this section in the spaces provided. 1 Fig. 1.1 shows a diagram showing the pathway of water into a plant. The arrows show the direction of water movement. Fig. 1.1 (a) (i) State the name of cell A and describe how it is adapted for absorption of water. name .……………………………… adaptation ....………………………………………………………………………….. ………………………………………………………………………………………….. …………………………………………………………………………………….. [1] (ii) Explain the movement of water from the soil water to the xylem vessel shown in Fig. 1.1. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. …………………………………………………………………………………….. [3] cortical cell xylem vessel soil water soil particle A

3 4E PRELIMINARY EXAM 2024 6093/02 1 (b) A student investigated the rate of transpiration in a plant. Fig. 1.2 is a diagram of the apparatus used in the investigation. Fig. 1.2 • The student watered the plant before the investigation started. • She measured the mass of water lost every five minutes. • The mass of water lost represents the rate of transpiration. • She took measurements in still air and with moving air surrounding the plant. • She plotted her results on a graph with lines labelled B and C. Fig. 1.3 shows the results. Fig. 1.3 balance plastic bag surrounding the pot to prevent water loss from the soil 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 0 5 10 15 20 25 30 time / minutes mass of water lost / g B C

4 4E PRELIMINARY EXAM 2024 6093/02 1 (b) (i) Identify the set-up which represents graph B and C. set-up with still air: graph ……… set-up with moving air: graph ……… [1] (ii) Explain the results in Fig. 1.3. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. …………………………………………………………………………………….. [3] (c) Aphids have been used to investigate the translocation of sucrose in phloem tissue. While they are feeding on phloem sap, aphids excrete a sucrose-rich fluid known as honeydew. In an investigation, two groups of four aphids were placed at intervals along the stem of a young willow plant, as shown in Fig. 1.4. Fig. 1.4 The leaves were enclosed in an airtight glass chamber. A special form of carbon dioxide gas that contained radioactive carbon -14 ( 14C) was supplied to the leaves for a short period of time. Samples of honeydew were collected at intervals from the two groups of aphids. The time taken for sucrose containing 14C to travel the distance between group A and group B was recorded. The investigation was repeated twice using a fresh stem and different groups of aphids for each trial. The results are shown in Table 1.1. glass chamber filled with carbon dioxide gas containing 14C Petri dishes for collecting honeydew group A group B damp cotton wool Petri dish with water

5 4E PRELIMINARY EXAM 2024 6093/02 1 (c) (i) Complete Table 1.1 by calculating the rate of movement of 14C in trial 3. Table 1.1 trial distance between group A and group B on the stem/mm time taken for 14C to travel between group A and group B /minutes rate of movement of 14C / mm per hour 1 650 120 325 2 340 75 272 3 630 150 [1] (ii) Outline how 14C in carbon dioxide gas becomes incorporated into the sucrose molecules that are translocated in the phloem. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. …………………………………………………………………………………….. [3] [Total: 12]

6 4E PRELIMINARY EXAM 2024 6093/02 2 Fig. 2.1 shows part of the alimentary canal and some of the associated organs. Fig. 2.1 (a) State the letter that represents the organ which produces bile. …………… [1] (b) A student investigated the effect of bile on the digestion of fat in milk. He set up three different test-tubes: • test-tube 1 contained milk and bile • test-tube 2 contained milk and lipase • test-tube 3 contained milk, lipase and bile. He used an indicator that is pink in alkaline solutions and colourless in acidic solutions. He added the same volume of indicator to each test-tube. The student observed and recorded the colour of the contents of each test-tube at 0 minutes, 20 minutes, and 40 minutes. Table 2.1 shows the results of the investigation. Table 2.1 test-tube indicator colour observed 0 minutes 20 minutes 40 minutes 1 pink pink pink 2 pink pink colourless 3 pink colourless colourless E A D B C

7 4E PRELIMINARY EXAM 2024 6093/02 2 (b) (i) Explain the results for test-tubes 2 and 3 in Table 2.1. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. ………………………………………………………………………………………….. …………………………………………………………………………………….. [3] (ii) Explain the purpose of test-tube 1 in Table 2.1. ………………………………………………………………………………………….. …………………………………………………………………………………….. [1] (c) The action of lipase is affected by temperature. Fig. 2.2 shows the axes for a graph of the effect of temperature on the activity of lipase. Complete the graph by: • drawing a line graph to show the expected effect of temperature on the activity of lipase • adding a label line and a label to show the point at which all the lipase has been denatured. temperature Fig. 2.2 [2] [Total: 7] enzyme activity

8 4E PRELIMINARY EXAM 2024 6093/02 3 Myopia is an eye condition. If a person has myopia, near objects can be seen clearly but not those that are far away. It can h