2026 CJC H2 Biology 9477 P1 QP

CATHOLIC JUNIOR COLLEGE JC2 PRELIM EXAMINATIONS Higher 2 CANDIDATE NAME CLASS INDEX NUMBER BIOLOGY 9744/01 Paper 1 Multiple Choice 12 SEPTEMBER 2024 1 Hour Additional Materials: OMR Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write and/or shade your name, NRIC / FIN number and HT group on the Answer Sheet in the spaces provided unless this has been done for you. There are thirty multiple choice 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 2B pencil on the separate OMR Answer Sheet. Read the instructions on the OMR 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.

2 This document consists of 25 printed pages and 1 blank page. [Turn over Answer all questions. 1 The electron micrograph below shows part of an animal cell. Which statements correctly describe the structure and function of the labelled regions? 1 Proteins and lipids received from the endoplasmic reticulum undergo chemical modification (such as glycosylation) within P . 2 Structure Q buds off from P and carries its contents toward R to be released via exocytosis. 3 The formation, movement, and fusion of structure Q with membrane R require energy in the form of ATP. 4 Structure P contains 70S ribosomes and circular DNA to independently synthesise its own enzymes. A 1, 2, 3, and 4 B 1, 2, and 3 only C 1 and 2 only D 3 and 4 only 2 Which of the following correctly identifies the structural features of a typical bacterial cell? Ribosomes Main Cell Wall Component Genetic Material Membrane-Bound Organelles A 70S Peptidoglycan Circular DNA Absent B 70S Cellulose Linear DNA Present C 80S Peptidoglycan Linear DNA Absent D 80S Chitin Circular DNA Present 2024 9744 JC2 PRELIMINARY EXAMINATION

3 3 Which of the following statements correctly describes the process that occurs when a molecule of glucose and a molecule of fructose join to form a molecule of sucrose? A A hydrolysis reaction takes place, which consumes one molecule of water. B A condensation reaction takes place, which releases one molecule of water. C A condensation reaction takes place, which consumes one molecule of water. D A hydrolysis reaction takes place, which releases one molecule of water. 4 Seeds of two plant species, X and Y, both store energy primarily as triglycerides. The table below shows the relative proportions of saturated and unsaturated fatty acids present in the triglycerides stored in seeds of both species, alongside the environmental temperature required during germination: Seed Species Saturated Fatty Acid Content / % Unsaturated Fatty Acid Content / % Germination Temperature / °C Species X 82% 18% 28 °C Species Y 15% 85% 4 °C Which statement correctly explains how the structural features of the triglycerides in species Y adapt its seeds for survival and germination at low temperatures compared to species X ? A Species Y triglycerides have a higher ratio of carbon-to-hydrogen (C-H) bonds, yielding more ATP per gram during aerobic respiration to compensate for lower enzyme kinetic energy at 4 °C. B Species Y triglycerides contain a higher proportion of hydroxyl groups (-OH), enabling hydrogen bonding with water to lower the intracellular water potential (Ψ) and prevent freezing of seed tissues. C Species Y triglycerides contain more carbon-to-carbon double bonds (C=C), creating kinks in the hydrocarbon chains that prevent close packing, maintaining lipid fluidity in cold storage droplets so lipases can access ester bonds for hydrolysis. D Species Y triglycerides contain shorter ester linkages that hydrolyse spontaneously at low temperatures without requiring activation energy from lipase enzymes. 2024 9744 JC2 PRELIMINARY EXAMINATION

4 5 An investigation was carried out to study the effect of temperature on the relative activity of an enzyme and its relative stability (the proportion of enzyme molecules retaining their native tertiary structure after incubation). The results are shown in the graph below. Which statement is the most valid conclusion supported by the data? A Between 20°C and 40°C, the rate of reaction increases because the proportion of stable enzyme molecules increases. B At 55°C, all enzyme molecules are completely denatured, preventing any substrate binding. C The decrease in relative activity above 45°C is primarily due to a decrease in the kinetic energy of the substrate molecules. D The peak in relative activity at 45°C occurs because increased molecular kinetic energy compensates for the slight loss in enzyme stability. 6 Two experiments were performed using mitochondria from mammalian liver cells. These mitochondria were placed in buffered isotonic solutions supplied with pyruvate, inorganic phosphate (P i ), ADP, and oxygen: Experiment 1: Intact mitochondria with both outer mitochondrial membrane (OMM) and inner mitochondrial membrane (IMM) fully functional. Experiment 2: Mitochondria treated with a chemical that removes the outer mitochondrial membrane (OMM) while leaving the inner mitochondrial membrane (IMM) intact and structurally undamaged. Which row in the table correctly predicts the effect on the proton gradient across the IMM and the rate of ATP synthesis in Experiment 2 compared to Experiment 1? Proton Gradient across IMM Rate of ATP Synthesis A Increased Increased B Unchanged Unchanged C Decreased Increased 2024 9744 JC2 PRELIMINARY EXAMINATION

5 D Decreased Decreased 7 The diagram below illustrates two different transport mechani