2026 EJC JC2 H2 Biology Prelims P2 (Q)

©EJC 2026 9477/02/J2H2PRELIM/2026 [Turn over EUNOIA JUNIOR COLLEGE JC2 Preliminary Examinations 2026 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 2 5 - REGISTRATION NUMBER H2 Biology Paper 2 Structured Questions 9477/02 02 September 2026 2 hours READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. Candidates are to answer: All questions on the Question Paper. Write your answers in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use paper clips, highlighters, glue, or correction fluid/tape. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 23 printed pages and 1 blank page. For Examiner’s Use 1 2 3 4 5 6 7 8 9 10 11 Total

2 ©EJC 2026 9477/02/J2H2PRELIM/2026 Answer all questions. 1 Amylose and triglyceride are macromolecules. (a) Explain why amylose and triglyceride are macromolecules, but only amylose is a polymer. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….… ………………………………………………………………………………………………………….[2] 1 (b) 2 State the number of oxygen atoms in one molecule of triglyceride. 3 4 ………………………………………………………………………………………………………….[1] (c) Contrast the structural features of amylose and the structural features of cellulose. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….… ………………………………………………………………………………………………………….… ………………………………………………………………………………………………………….[3] [Total: 6]

3 ©EJC 2026 9477/02/J2H2PRELIM/2026 [Turn over 2 A student constructed a table to compare the structural features of a plant cell, a bacterial cell, and a virus. (a) Complete Table 2.1. Table 2.1 feature plant cell bacterial cell virus external structure cell wall composed of cellulose cell wall composed of ……………………………… capsid composed of capsomeres size(s) of ribosomes …………………… 70S no ribosomes genetic material DNA DNA …………………… [3] (b) The cholera bacterium, Vibrio cholerae, releases a toxin called choleragen. The toxin causes the loss of chloride ions and water from epithelial cells into the lumen of the intestine, causing severe watery diarrhoea. Fig. 2.1 shows the events that occur in cells lining the intestine when choleragen binds to the cell surface membrane of one of these epithelial cells. Fig. 2.1 (i) State the type of molecule that forms the receptor for choleragen. …………………………………………………………………………………………………..[1]

4 ©EJC 2026 9477/02/J2H2PRELIM/2026 (ii) The process by which chloride ions leave the epithelial cell requires energy. State and describe this process. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. …………………………………………………………………………………………………..[3] (iii) Explain the movement of water molecules when choleragen is present. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. …………………………………………………………………………………………………..[2] [Total: 9]

5 ©EJC 2026 9477/02/J2H2PRELIM/2026 [Turn over 3 The lock-and-key hypothesis and the induced-fit hypothesis are used to describe the interaction of enzymes and their substrates. (a) Describe one similarity and one difference between the lock -and-key hypothesis and the induced-fit hypothesis. similarity ………………………………………………………………………………………………… ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. difference ……………………………………………………………………………………………… ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………… [2] (b) Fig. 3.1 summarises the reaction catalysed by lactase. Draw the ring structure of α-glucose in the box provided to complete Fig. 3.1. Fig. 3.1 [1]

6 ©EJC 2026 9477/02/J2H2PRELIM/2026 (c) The lactose in milk can be hydrolysed using immobilised lactase or free lactase ( lactase in solution). This results in milk and milk products that do not contain lactose and so are suitable for lactose-intolerant people. Scientists carried out an investigation to compare the activity of lactase immobilised in very small magnetic beads (magnetic microspheres) with free lactase, at different temperatures and at different pH values. Fig. 3.2 shows the activity of immobilised lactase and the activity of free lactase at 5 different temperatures. Fig. 3.3 shows the activity of immobilised lactase and the activity of free lactase at 8 different pH values. Fig. 3.2 Fig. 3.3

7 ©EJC 2026 9477/02/J2H2PRELIM/2026 [Turn over One advantage of using magnetic microspheres with immobilised lactase is that they can be easily recovered using an electric field and reused. With reference to Fig. 3.2 and Fig. 3.3, explain why the results indicate that there are other advantages in using immobilised lactase instead of free lactase to produce lactose -free products. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….… ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….… ………………………………………………………………………………………………………….… ………………………………………………………………………………………………………….[4] [Total: 7]

8 ©EJC 2026 9477/02/J2H2PRELIM/2026 4 Blood stem cells in the bone marrow are essential for maintaining a healthy volume of blood cells in the human body. However, errors during their cell cycle can occasionally lead to the formation of blood cancers like leukaemia. (a) State two unique features of blood stem cells that allow them to fulfil their normal physiological functions in the bone marrow. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….[2] (b) Explain the role of the G 2 checkpoint in maintaining genetic stability during the normal mitotic division of these stem cells. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….[2] (c) Even if a single stem cell evades the cell cycle checkpoints and proliferates excessively, it does not immediately become a full-fledged, malignant cancer. Describe two other critical genetic changes that must occur for this mass of cells to successfully establish a secondary tumour. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….… ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….… ………………………………………………………………………………………………………….… ………………………………………………………………………………………………………….[4]

9 ©EJC 2026 9477/02/J2H2PRELIM/2026 [Turn over (d) Genomic analysis of the leukaemia cells reveals a loss -of-function mutation in both alleles of the p53 gene. Explain how this specific mutation contributes to uncontrolled cell division. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. ………………………………………………………………………………………………………….[2] [Total: 10] 5 Scientists investigated a newly discovered strain of Streptococcus bacteria that rapidly acquired