2023_EJ_P1_Bio_Prelim_Ans_

©EJC 2023 9744/01/J2H2PRELIM/2023 [Turn over EUNOIA JUNIOR COLLEGE JC2 Preliminary Examination 2023 General Certificate of Education Advanced Level Higher 2 H2 Biology Paper 1 Multiple Choice 9744/01 22 September 2023 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use paper clips, glue or correction fluid/tape. Write your name, civics group and registration number on the Answer Sheet in the spaces provided. 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 22 printed pages and 2 blank pages.

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3 ©EJC 2023 9744/01/J2H2PRELIM/2023 [Turn over Answer all questions. 1 Disaccharides are formed following synthesis from monosaccharides or as a result of polysaccharide hydrolysis. Cellobiose, maltose, sucrose and trehalose are four different disaccharides found in nature. Some features of these disaccharides are listed. • Cellobiose is formed from the hydrolysis of the polysaccharide cellulose. • Sucrose is composed of glucose and fructose. • Trehalose is a non -reducing disaccharide that is synthesised from two α -glucose molecules. • Maltose is formed from the hydrolysis of amylose, a component of starch. Which column correctly identifies each disaccharide? A B C D cellobiose maltose sucrose trehalose maltose cellobiose trehalose maltose sucrose trehalose cellobiose cellobiose trehalose sucrose maltose sucrose Option A – sucrose cannot be made of two glucose joined by β -glycosidic bonds, cellobiose should be two glucose joined by β-glycosidic bonds which is not the case. Option B – we can eliminate this choice based on the diagrams for maltose cellobiose and trehalose. Option C – we can eliminate via sucrose, trehalose and , maltose.

4 ©EJC 2023 9744/01/J2H2PRELIM/2023 2 When hydrolysed, which molecules have products containing carboxyl groups? 1 phospholipids 2 polysaccharides 3 proteins A 3 only B 1 and 2 C 1 and 3 D 2 and 3 Phospholipids have fatty acid hydrocarbon tails, hence there are carboxyl groups in these molecules. Proteins are made up of amino acids which have carboxyl and amino groups. 3 How many different polypeptides, each of 100 amino acids, can be made if the number of different amino acids available is 10? A 10010 B 10100 C 1000 D 10 Since there are only 10 amino acids available, the total number 100-amino acid polypeptid