2020 EJC Promo JC1 P1 Bio (A)

©EJC 2020 9744/01/J1H2PROMO/2020 [Turn over EUNOIA JUNIOR COLLEGE JC1 Promotional Examinations 2020 General Certificate of Education Advanced Level Higher 2 H2 Biology Paper 1 Multiple Choice 9744/01 02 October 2020 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. Write your name, civics group and registration number on the Answer Sheet in the spaces provided. There are thirty Multiple Choice Questions in 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 21 printed pages and 1 blank page.

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3 ©EJC 2020 9744/0J1H2PROMO/2020 [Turn over 1 Both -amylase and -amylase can hydrolyse -1,4-glycosidic bonds, but not -1,6-glycosidic bonds. -amylase acts randomly within polysaccharides and can produce glucose, maltose, trisaccharides and short, branched chains. -amylase acts at the ends of polysaccharides to produce maltose molecules. Which of the following statements about polysaccharide digestion is correct? A Both -amylase and -amylase are needed for the complete digestion of starch to produce only glucose molecules. B Digestion of amylose by -amylase will produce branched molecules only. C Digestion of amylose using -amylase will yield a higher proportion of disaccharides than digestion using -amylase. D Disaccharides can be produced from the digestion of cellulose using -amylase, but not -amylase. 2 The table below shows the percentages of carbon, hydrogen and oxygen atoms in molecules X, Y and Z. molecule % carbon % hydrogen % oxygen X 25.0 50.0 25.0 Y 28.5 47.7 23.8 Z 34.6 61.6 3.8 Which row correctly identifies molecules X, Y and Z? X Y Z A monosaccharide disaccharide polysaccharide B monosaccharide polysaccharide triglyceride C polysaccharide triglyceride monosaccharide D triglyceride monosaccharide polysaccharide

4 ©EJC 2020 9744/01/J1H2PROMO/2020 3 Threonylvaline is a dipeptide formed from two amino acids, valine and threonine. A peptide bond forms between the amino group of valine and carboxyl group of threonine. The R groups of the two amino acids are shown. Which of the following is the molecular structure of threonylvaline? A B C D

5 ©EJC 2020 9744/0J1H2PROMO/2020 [Turn over 4 The diagram shows the structure of HLA-DR1, which is a cell surface membrane receptor. HLA-DR1 consists of tw