PLMGSS 2024 4E ScBio P4 QP

1 [Turn over] CANDIDATE NAME CLASS CLASS INDEX NUMBER TG CENTRE NUMBER INDEX NUMBER SCIENCE (BIOLOGY) 5088/4 Paper 4 Biology 16 August 2024 No additional materials are required. 1 hour 15 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and class index number on the front cover. Write in dark blue or black pen. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. The use of an approved calculator is expected, where appropriate. Section A (55 marks) Answer all questions. Write your answers in the spaces provided on the question paper. Section B (10 marks) There are two questions in this section. Answer only one question. Write your answers in the spaces provided on the question paper. At the end of the test, fasten all your work securely together, if applicable. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 19 printed pages. For Examiner’s Use Section A 55 Section B 10 7 8 Total 65 Paya Lebar Methodist Girls’ School (Secondary) Preliminary Examination 2024 Secondary 4 Express (G3)

2 [Turn over] Section A (55 marks) Answer all the questions in the spaces provided. 1 Digestive enzymes catalyse the breakdown of large insoluble molecules. (a) Explain why it is important that large insoluble molecules are broken down by chemical digestion. ………………………………………………………………….……………………………..…. ………………………………………………………………………………………..…... [1] (b) (i) Fig. 1.1 shows the action of an enzyme. On Fig. 1.1, use label lines and labels to identify the enzyme, product and substrate that can be found in the stomach. Fig. 1.1. [1] (ii) Define enzyme. ………………………………………………………………….……………………………..…. ………………………………………………………………….……………………………..…. ………………………………………………………………….……………………………..…. ………………………………………………………………………………………..…... [2]

3 [Turn over] (c) An enzyme X in biological washing pow ders speed up the removal of stains from clothing. Some of these stains may contain fats. A student investigated the effect of a bile-like substance to increase the effectiveness of the washing powder. He tested the effect of bile on the digestion of fats in milk. She used an indicator that is pink in alkaline solutions and colourless in acidic solutions. She 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 1.1. shows the results of the investigation. Table 1.1 set-up indicator colour observed test tube content 0 minutes 20 minutes 40 minute