2025 NJC H2 Biology Prelims Paper 4_QP

© NJC 2025 9744/04/SH2 Preliminary Examination [Turn over NATIONAL JUNIOR COLLEGE, SINGAPORE Senior High 2 Preliminary Examination Higher 2 CANDIDATE NAME BIOLOGY CLASS 2bi2_____ REGISTRATION NUMBER Biology Paper 4 Practical 9744/04 3 September 2025 2 hours 30 minutes READ THESE INSTRUCTIONS FIRST Write your name, Biology class, and registration number 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 the brackets [ ] at the end of each question or part question. Shift 1 2 3 Laboratory BI23 BI24 CM43 CM44 For Examiner’s Use 1 35 2 20 Total 55 This document consists of 19 printed pages and 1 blank page.

2 © NJC 2025 9744/04/SH2/H2 Biology/Preliminary Examination Answer all questions. 1 Plants can be categorised into sun and shade plants. Sun plants need more sunlight than shade plants for photosynthesis. Sun plants are exposed to high sunlight intensity and hence are adapted against overheating and desiccation, while shade plants have little exposure to sunlight and hence are adapted to be more efficient in absorbing light for photosynthesis. Chloroplasts were isolated from these two types of plants and suspended in a buffer solution. You are required to: ● immobilise chloroplast in sodium alginate beads, and ● investigate the effect of immobilised chloroplast from sun and shade plants on the rate of photosynthesis. During the light-dependent stage of photosynthesis, hydrogen ions and electrons are transferred to hydrogen acceptor molecules, including NADP. Potassium permanganate can be used as an indicator to monitor the rate of the light-dependent stage of photosynthesis. When potassium permanganate is reduced, it turns from purple-pink to colourless. You are provided with: ● chloroplast suspensions S1 and S2 from the two types of plants ● sodium alginate solution, labelled A ● calcium chloride solution, labelled C ● dilute sulfuric acid, H2SO4 ● potassium permanganate solution, KMnO4 ● distilled water, labelled W ● a lamp. Dilute sulfuric acid and potassium permanganate are corrosive. If they come into contact with your skin, wash them off immediately under cold water. Read steps 1–18 before starting the investigation. Proceed as follows. 1 Put 20.0 cm3 of C into a small beaker. 2 Put 5.0 cm3 of A into a separate small container. 3 Stir the chloroplast suspension in S1 thoroughly. 4 Put 5.0 cm3 of S1 into the same contai