QTSS Prelim 2024 Sec 4E Science (Biology) P4 [5087]

This document consists of 19 printed pages. Name: ………………………………………………….. ( ) Class: Sec 4 SG2 Queenstown Secondary School Preliminary Examination 2024 Secondary Four Express Science (Biology) 5087/04 27 August 2024 Time: 1045 – 1200 h Tuesday Duration: 1 hour 15 minutes Setter: Additional Materials: Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. You may use an HB pencil for any diagrams, graphs, tables or rough working. Write in dark blue or black pen. Do not use staples, paper clips, glue or correction fluid. 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. Section A Answer all questions. Write your answers in the spaces provided on the question paper. Section B Answer one question. Write your answers in the spaces provided on the question paper. The number of marks is given in brackets [ ] at the end of each question or part question. Examiner’s Use Section A /55 Section B /10 Q10 Q11 TOTAL /65

2 Queenstown Secondary School [Turn over Section A Answer all the questions in the spaces provided. 1 Beetroot cells contain a purple pigment in their cytoplasm. In an experiment, 6 strips of similar size were cut from a beetroot and thoroughly washed with water until the water was clear. Two strips each were weighed and then put into 3 different test tubes A to C as shown in Fig. 1.1. The setups were then left for 30 minutes. (a) State and explain the change in mass of the beetroot strips in test -tube A at the end of the experiment. change in mass of beet root strips in A: …………..………...…………………… ……………………………….…………………………………....…………………… explanation: …….………………….…………………………...…………………… ……………………………….…………………………………....…………………… ……………………………….…………………………………....…………………… …………………….………………….…………………………...…………………… ……………………………….…………………………………....…………………… [3] Hot water (90oC) turned purple at end of experiment Fig. 1.1

3 Queenstown Secondary School [Turn over (b) (i) The liquid in test-tube C appears purple at the end of the experiment. State the reason for the change in the colour of the liquid in test-tube C. ………………….………………………………………...…………………… ………………..……………….…………………………………....…………. ………………….………………………………………...…………………… ………………..……………….…………………………………....…………. [1] (ii) Predict, with an explanation, the appearance of the liquid in test-tube B at the end of experiment. ………………….………………………………………...…………………… ………………..……………….…………………………………....…………. ………………….………………………………………...…………………… ………………..……………….……………