ASRJC 2023 JC2 H2 Biology Prelims Paper 2 (QP)

ASRJC BIOLOGY DEPT 9744/2023/J2PRELIM/P2 [Turn over H2 ANDERSON SERANGOON JUNIOR COLLEGE HIGHER 2 2023 JC2 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS INDEX NUMBER BIOLOGY 9744/02 PAPER 2 SHORT STRUCTURED QUESTIONS Candidates answer on the Question Paper. No Additional Materials are required. 13 SEPTEMBER 2023 WEDNESDAY 2 HOURS READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graph. Do not use paper clips, highlighters, glue or correction fluid. Answer all questions. 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. This document consists of 32 printed pages. For Examiner’s Use 1 2 3 4 5 6 7 8 9 10 11 Total /100

2 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P2 Answer all questions. 1 Archaea are single-celled micr oorganisms which inhabit extrem e environments, such as hot springs and volcanic vents at temperatures over 100 C. Fig. 1.1 shows the molecular structure of a phospholipid found in the cell membrane of an archaea and that of a eukaryote. Fig. 1.1 (a) (i) With reference to Fig. 1.1, state two structural differences between the two phospholipids. ……………………………………………………………………………………………….... ……………………………………………………………………………………………….... …………………………………………………… …………………………………………… …………………………………………………… …………………………………………… …………………………………………………… ………………………………………..[2]

3 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIM/P2 [Turn over (ii) Explain why phospholipids are unable to provide structural support. ……………………………………………………………………………………………….... ……………………………………………………………………………………………….... ……………………………………………………………………………………………….... ……………………………………………………………………………………………….... …………………………………………………… …………………………………………… …………………………………………………… …………………………………………… ………………………………………………………………………………………………[3]

4 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P2 (b) In an experiment to investigate the transport of ions into root cells, some pea plants were grown with their roots in a solution of ions. These ions were absent in the root cells at the beginning of the experiment. The concentration of five ions in the soluti on and in the cytoplasm of root cells were determined after one hour. The results are shown in Table 1.1. Table 1.1 ion concentration of ions / mmol dm -3 solution cytoplasm of root cells potassium (K+) 1.0 75.0 magnesium (Mg2+) 0.3 3.5 calcium (Ca2+) 1.0 1.0 phosphate (PO43-) 1.0 21.1 sulfate (SO42-) 0.3 19.7 Explain which components of the cell surface membrane of root cells are responsible for the results shown in Table 1.1. ……………………………………………………… ……………………………………………….. ……………………………………………………… ……………………………………………….. ……………………………………………………… ……………………………………………….. ……………………………………………………… ……………………………………………….. ……………………………………………………… ……………………………………………….. ……………………………………………………… ……………………………………………….. ……………………………………………………… ……………………………………………….. ……………………………………………………… ……………………………………………...[4] [Total: 9]

5 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIM/P2 [Turn over Question 2 starts on page 6

6 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P2 2 Fig. 2.1 is a photomicrograph of root tip cells at different stages in the cell cycle. A cell in interphase and telophase are labelled. Fig. 2.1 (a) (i) Complete Fig. 2.1 by naming the stage of mitosis shown in each of cells J and K. [1] (ii) State one feature of the cell in interphase, visible in Fig. 2.1, that shows this cell is not in early interphase. …………………………………………………………………………………………….…….. …………………………………………………………………………………………….….[1] (b) Describe the events that occur in telophase. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………...[2]

7 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIM/P2 [Turn over (c) Reduction division happens in meiosis. (i) Describe the events that cause reduction division. ……………………………………………………… ……………………………..………….... …………………………………………………………………………………………..…….... ……………………………………………………… …………………………………………... ……………………………………………………… ……………………………….……..…… …………………………………………………………………………………………..…..….. ……………………………………………………… …………………………………….….[2] (ii) Explain the need for reduction division during meiosis. ……………………………………………………… …………………………………………... ……………………………………………………… …………………………………………... ……………………………………………………… …………………………………………... ……………………………………………………… …………………………………………... ……………………………………………………… ………………………………………...… ……………………………………………………… ……………………………………….….. ……………………………………………………… …………………………………….….[3] [Total: 9]

8 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P2 3 Fig. 3.1 shows the cell signalling pathways of insulin and glucagon in liver cells. Fig. 3.1 (a) State the role of phosphate in Fig. 3.1. ………….……………………………………………………………………………………….…….. ………………………………………………………………………………….……………….….[1] (b) Explain how the properties of the cell surface membrane facilitate the cell signalling pathways in Fig. 3.1. ……………………………….…………………… ………………………………………………….. ………………………………………………….… ………………………………………………….. ………………………………………………………….…………………………………………….. ………………………………………………………. ……………………………………………….. ………………………………………………………….…………………………………………….. …………………………………………………… ……….………………………………………….. ……………………………………………………………….……………………………………….. ……………………………………………………………………………………………………...[4]

9 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIM/P2 [Turn over (c) PKA is an enzyme involved in the signalling pathways in Fig. 3.1. Explain how the features of PKA allow it to perform its function in cell signalling. …………………………………………………………… ………………………………………..….. ……………………………..……………………………… ………………………………………….. ………………………………………………………………..……………………………………….. …………………………………………………………… ……………..…………………………….. …………………………………………………………… …………..……………………………….. …………………………………………………….. ………………………………………………….. …………………………………………………………..…………………………………………….. …………………………………………………………