2025 YIJC [H2] Prelim P1 (A) with Examiner Report

©YIJC 9744/01/PE/2025 [Turn over YISHUN INNOVA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CG INDEX NO BIOLOGY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet 9744/01 19 September 2025 1 hour READ THESE INSTRUCTIONS FIRST Do not use staples, paper clips, glue or correction fluid/tape. Write your name, index no. and CG on this cover page and OTAS provided unless this has been done for you. 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. 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. This document consists of 24 printed pages. ANSWERS

2 ©YIJC 9744/01/PE/2025 [Turn over 1 Which row correctly describes a cell organelle? organelle description A centriole a hollow cylinder that generates spindle microtubules and is enclosed by a single membrane B lysosome a spherical sac containing digestive enzymes that is formed by the smooth endoplasmic reticulum C mitochondrion a single membrane enclosing an inner membrane folded into cristae to house electron transport chains D ribosome two unequal subunits made of rRNA and proteins, attached permanently to the rough endoplasmic reticulum A – Incorrect: A centriole is a hollow cylinder made of nine triplets of microtubules and is not surrounded by any membrane. B – Incorrect: Lysosomes are spherical sacs containing digestive enzymes, but they are formed by the RER & Golgi apparatus, not the smooth endoplasmic reticulum. C – Correct: A mitochondrion has a double membrane — an outer membrane and a folded inner membrane (forming cristae) D – Incorrect: Ribosomal subunits are unequal in size (large and small subunit) and are found free in the cytoplasm or attached to the rough ER ER: Poorly done. Only 28% of candidates answered correctly. Most chose A (31%) or B (34%) instead of the correct answer C.

3 ©YIJC 9744/01/PE/2025 [Turn over 2 The table compares some features of three different proteins, P, Q and R. Of these proteins: • one has a fibrous quaternary structure • one has a globular tertiary structure • one has a globular quaternary structure protein number of genes coding for the protein % of protein composed of the commonest amino acid % of protein composed of small amino acids durability P 2 46 77 less sensitive to changes in pH and