TMJC 2023 H2 P2 QP

1 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Biology CANDIDATE NAME CIVICS GROUP H2 BIOLOGY 9744/02 Paper 2 Structured Questions 14 September 2023 2 hours Candidates answer on the Question Paper. No additional materials are required. READ THESE INSTRUCTIONS FIRST Write your name and Civics Group in the spaces at the top of the page. 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. The number of marks is given in brackets [ ] at the end of each question or part question. ______________________________________________________________________________________ This document consists of 26 printed pages and 2 blank pages. For examiner’s Use 1 / 11 2 / 11 3 / 11 4 / 12 5 / 15 6 / 9 7 / 12 8 / 10 9 / 9 Total / 100 TAMPINES MERIDIAN JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION

2 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Biology 1 The table below compares the features of typical eukaryotic and prokaryotic cells. (a) Complete the table below by placing either a tick (), a cross () or the words ‘sometimes present’ as appropriate in each empty box. [3] Features Eukaryotic cell Prokaryotic cell nuclear envelope  cell wall sometimes present  chloroplast sometimes present ribosomes   Golgi apparatus   flagellum sometimes present carries out respiration   Active transport and facilitated diffusion are two ways by which substances cross the cell surface membranes. (b) State one similarity and one difference between active transport and facilitated diffusion. [2] similarity…………………………………………………………………………………………….... ……………………………………………………………………………………………................. difference…………………………………………………………………………………………… .. ……………………………………………………………………………………………................. (c) Vitamins C and D are essential illness -fighting nutrients, which safeguard our health and boost immunity. They are therefore, taken into cells but take different routes across the cell surface membrane. Vitamin C is water-soluble while Vitamin D is lipid soluble. Explain how Vitamin C and D is transported across the cell surface membrane. [3] Vitamin C ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. ……………………………………………………………………………………………………….. Vitamin D ………………………………………………………………………………………………………. ……………………………………………………………………………………………................ ……………………………………………………………………………………………………….

3 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Biology (d) A vitamin C drink is thought to contain glucose. Excess glucose consumed is stored as glycogen in muscles. Explain how the structure of glycogen is related to its role in living organisms. [3] ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. ……………………………………………………………………………………………………… .. ……………………………………………………………………………………………................. [Total:11]

4 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Biology 2 (a) Enzymes speed up the rate of reaction by lowering the activation energy of the reaction. Most enzymes are specific to one reaction. Outline how enzymes lower the activation energy of a reaction. [2] ……………………………………………………………………………………………................. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. ……………………………………………………………………………………………………….. A tyrosine kinase receptor (TKR) is a protein complex found in the cell surface membrane of mammalian cells. TKR has two components involved in the process of cell signaling: • a receptor for the signalling molecule (ligand) • an enzyme that catalyses the transfer of a phosphate group from ATP to an intracellular protein. Fig. 2.1 is a diagram to show how TKR is involved in cell signalling. Fig. 2.1

5 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Biology (b) Describe how the signalling molecule shown in Fig. 2.1 is able to trigger a response inside the target cell. [3] ……………………………………………………………………………………………................. ………………………………………………………………………………………………… …….. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. …………………………………………………………………………………………….................

6 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Biology (c) The drug GNF-5 is used in the treatment of some cancers. GNF-5 affects the activity of TKR by binding to the enzyme component of the complex. Researchers investigated the effect of GNF-5 on the activity of TKR using different concentrations of ATP solution. In an experiment the activity of TKR was measured with no GNF-5 and with GNF-5. The results are shown in Fig. 2.2. Fig. 2.2 Use Fig. 2.2 to provide evidence that GNF-5 acts as a competitive inhibitor. [3] ……………………………………………………………………………………………................. ………………………………………………………………………………………………… …….. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………................. …………………………………………………………………………………………….................

7 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Biology (d) A mutation of the gene coding for TKR results in the change to the enzyme component of TKR. This altered form of TKR is known as T315L. The effect of GNF-5 on the activity of T315L was also investigated. The results of this investigation are shown in Fig. 2.3. Fig. 2.3 Use Fig. 2.2 and Fig. 2.3 to (i) state how the activity of T315L differs from TKR when no GNF-5 was present. [1] ……………………………………………………………………………………………………. …………………………………………………………………………………………………..... (ii) explain why the effect of GNF-5 on T315L differs from the effect of GNF-5 on TKR. [2] ……………………………………………………………………………………………………. ………………………………………………………………………………………………….... ……………………………………………………………………………………………………. ………………………………………………………………………………………………….... …………………………………………………………………………………………………….