TJC 2023 JC1 H2 BIO EOY P1 QP

1 [Turn over TEMASEK JUNIOR COLLEGE PROMOTIONAL EXAMINATION JC1 2023 READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, civics group and index number on the Multiple Choice Answer Sheet (MCAS). Write in soft pencil. Do NOT use staples, paper clips, glue or correction fluid. There are twenty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. The use of an approved scientific calculator is expected, where appropriate. Note: The OMS will be collected after 40 minutes during the examination. This document consists of 12 printed pages. H2 BIOLOGY 9744 Section A Multiple Choice Friday, 22 September 2023 2 hours and 40 minutes Additional Materials: Multiple Choice Answer Sheet

2 [Turn over Section A Answer all the questions in this section. 1 In the diagram below (not drawn to scale), which of the labeled parts, A, B, C or D does not contain nucleic acids? BLANK PAGE 2 The table provides the description of four membranous structures in a cell. Which structure is correctly matched with its function? Structure Function A An extensive network of tubes and sacs; each tube and sac bounded by a single membrane Lipid synthesis B A spherical sac bounded by a single membrane Protein synthesis C A sac bounded by two membranes, the inner membrane is highly folded Packaging of proteins D A stack of elongated, curved sacs; each sac bounded by a single membrane Photosynthesis 3 Some organisms change the composition of their membranes to maintain membrane fluidity when the temperature changes. Which changes occur in the composition of the membranes following a change to low temperature? A Increase phospholipids, decrease cholesterol. B Increase saturated fatty acids, increase cholesterol. C Increase saturated fatty acids, decrease cholesterol. D Increase unsaturated fatty acids, increase cholesterol.

3 4 Which of the following curves best represent the movement of substances into a cell by simple diffusion and facilitated diffusion? Simple diffusion Facilitated diffusion A W Y B W X C X Z D X W 5 The diagram shows the structure of two lipid molecules. Which statements correctly describe the two lipid molecules? 1. Both molecules are esters of glycerol. 2. Both molecules are made by condensation reactions. 3. The hydrocarbon chains of molecule X are always from saturated fatty acids. 4. The hydrocarbon chains of molecule Y m