2026 ASRJC H2 Biology Prelim P1 (Answer)

ASRJC BIOLOGY DEPT 9477/2026/J2PRELIMS/P1 [Turn over 2026 JC2 PRELIMINARY EXAMINATIONS BIOLOGY 9477/01 PAPER 1 2 SEPTEMBER 2026 MULTIPLE CHOICE WEDNESDAY 1 HOUR Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and identification number on the MCQ Answer Sheet. There are thirty 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. 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 scientific calculators is expected, where appropriate. This document consists of 23 printed pages and 1 blank page. H2 ANDERSON SERANGOON JUNIOR COLLEGE HIGHER 2

2 ASRJC BIOLOGY DEPT 9477/2026/J2PRELIMS/P1 1 An electron micrograph of a eukaryotic cell shows three structures, 1, 2 and 3. A blue dye specific for polynucleotides was used to stain this cell. Which of these structures will be dyed blue? Structure 1: nucleus (clue would be the lightly and darkly stained regions) contains DNA so will be stained blue. Structure 2: RER (continuous with the nuclear envelope) contains ribosomes that are the site of translation using mRNA as a template, so will also be stained blue. Structure 3: secretory vesicle (numerous, and close proximity to the cell surface membrane (not shown)) only carries proteins so will not be stained blue. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only

3 ASRJC BIOLOGY DEPT 9477/2026/J2PRELIMS/P1 [Turn over 2 Which of the following describes a lysosome? A a vesicle containing enzymes, enclosed by a double membrane, that is budded off the endoplasmic reticulum  Lysosome is single membrane, not double membrane. Lysosome also budded off from GA, not RER. B a vesicle containing hydrolytic enzymes and surrounded by a single membrane, found only in phagocytes  Lysosome can also be found in other animal cells, not just in phagocytes. C a vesicle enclosed by a single membrane, containing several different hydrolytic enzymes tha t can act inside the cell ✓ Lysosomes can fuse with other vesicles (e.g. phagosome) or worn -out organelles to digest the contents. D a vesicle surrounded by a double membrane, containing enzymes which can hydrolyse damaged organelles in a cell  Lysosome is single membrane, not double membrane. 3 Which statement about triglycerides is correct? A Triglycerides have a higher proportion of oxygen than carbohydrates. Incorrect. Triglycerides have a lower proportion of oxygen than carbohydrates . Both contain carbon, hydrogen and oxygen, but triglycerides contain proportionally much less oxygen but more hydrogen and carbon. This contributes to triglycerides having a higher energy content per unit mass than carbohydrates. B Two triglycerides are joined together by an ester bond. Incorrect. Within a triglyceride, ester bonds are formed between the hydroxyl groups of glycerol and the carboxyl groups of three fatty acids during condensation reactions, not between two triglyceride molecules. C Triglycerides are soluble in water if they contain unsaturated fatty acids. Incorrect. Most triglycerides are insoluble in water because they contain non -polar, hydrophobic fatty acid chains and are therefore hydrophobic. Those with shorter fatty acid chains may have slightly greater water solubility. Unsaturation affects melting point. Unsaturated fatty acids, have C=C double bonds,resulting in kinks in their fatty chains. These prevent the molecules from packing closely together → lower melting point

4 ASRJC BIOLOGY DEPT 9477/2026/J2PRELIMS/P1 D Glycerol is joined to each fatty acid by a covalent bond. Correct. Each fatty acid is joined to glycerol by a covalent ester bond. A triglyceride contains one glycerol molecule joined to three fatty acids, so three ester bonds are formed. 4 Collagen is a fibrous protein found in mammalian tendons. Which feature contributes to the great tensile strength of collagen? A A primary structure with covalent bonds linking a large variety of amino acids.  Collagen has a fixed (and not variable) motif of repeated amino acids, glycine-X-Y. B A regularly folded tertiary structure held together with hydrogen bonds and ionic bonds.  Collagen does not have a tertiary structure. C A quaternary structure with many hydrogen bonds firmly holding the α-helices.  Collagen subunit is a triple helix, not alpha helix. D A quaternary structure of triple helix held together by hydrogen bonds between the three polypeptides. ✓ This is a correct description of the collagen subunit, tropocollagen, that is held together by inter-chain hydrogen bonds. 3 ester bonds

5 ASRJC BIOLOGY DEPT 9477/2026/J2PRELIMS/P1 [Turn over 5 The components of the membranes found within and at the surface of cells contribute to their functions. Examples of components are shown below. 1 glycolipids 2 glycoproteins 3 phospholipids 4 proteins Which row matches the components with their functions? binding sites for toxins recognising self from non-self separating dissolved ions transporting ions through membranes binding cells together Glycolipids and/or glycoproteins are involved in cell signaling/ receiving signals from the extracellular environment Glycolipids and/or glycoproteins are involved in cell-cell recognition Phospholipid bilayer forms the cell surface membrane. Phospholipid bilayer has a hydrophobic core which hydrophilic ions cannot pass through. Hence ions are separated on either side of the membrane. Ions are hydrophilic. They cannot pass through the hydrophobic core of the cell membrane. Transport proteins are required transport ions. Glycolipids and/or glycoproteins are involved in cell- cell adhesion A 1 1 4 3 2 B 3 2 3 4 1 C 1 2 4 2 2 D 1 2 3 4 1

6 ASRJC BIOLOGY DEPT 9477/2026/J2PRELIMS/P1 6 The enzyme invertase catalyses the breakdown of sucrose to glucose and fructose. Three different enzyme inhibitors of invertase, X, Y and Z were investigated. The percentage inhibition of invertase was measured at different concentrations of inhibitor. The graph shows the results of the investigation.