JPJC 2023 J2 H2 BI Prelim P1 QP

9744 / 01 [Turn over NAME: CLASS: JURONG PIONEER JUNIOR COLLEGE JC2 Preliminary Examination 2023 BIOLOGY Higher 2 9744/01 19 September 2023 Paper 1 Multiple Choice 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 index number on the Answer Sheet in the spaces 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 17 printed pages and 3 blank pages.

2 JPJC/JC2 H2 Biology/Prelims/2023 1 A molecule of carbon dioxide is in the centre of a mitochondrion. Assuming there are no other cell structures in its path, how many phospholipid layers will the carbon dioxide molecule have to pass through to leave the cell? 9700_s20_qp_13 A 2 B 3 C 4 D 6 2 Which nitrogenous bases are present in all viruses? 1 thymine 2 adenine 3 cytosine A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 3 The enzyme α-amylase hydrolyses amylopectin but it is not able to hydrolyse some of its glycosidic bonds. • It only hydrolyses 1,4 glycosidic bonds. • It is not able to hydrolyse the last bond of a chain. • It is not able to hydrolyse the bonds in a chain of three units attached by a 1,6 glycosidic bond to another chain. Which glycosidic bond can be hydrolysed by α-amylase?

3 JPJC/JC2 H2 Biology/Prelims/2023 [Turn over 4 When investigating the rate of reaction of the enzyme lipase on the hydrolysis of triglycerides, the pH must be maintained at an optimum to prevent the lipase denaturing. What is the reason for this? A The addition of water molecules produced by hydrolysis increases pH. B The products of hydrolysis decrease the pH. C The products of hydrolysis increase the pH. D The removal of water molecules used in hydrolysis decreases pH. 5 Four mechanisms involved in the movement of substances across membranes are shown below. Which features of these transport mechanisms are represented by P, Q and R? P Q R A involves membrane carrier proteins passive movement movement against a concentration gradient B involves membrane transport proteins movement down a concentration gradient passive movement C movement against a concentration gradient involves membrane channel proteins movement through the hydrophobic core