DHS 2022 Y5 H2 Promo Paper 1 (QP)

© DHS 2022 9744/01 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Promotional Examination Year 5 H2 BIOLOGY 9744/01 Paper 1 Multiple Choice Questions 27 September 2022 Additional Materials: Multiple Choice Answer Sheet 30 minutes READ THESE INSTRUCTIONS FIRST: Write your class, index number and name at the top of this page. There are fifteen 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. 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. Write your name and class on the Multiple Choice Answer Sheet. Write and shade the Index Number as follows. This document consists of 12 printed pages. For illustration only: A student from class 5C41, with index number 01, should shade “4101”. 4 1 0 1

2 © DHS 2022 9744/01 1 The figure shows an E. coli engulfed by a basophil, a type of white blood cell. Ramzi S Cotran & Mortimer Litt, 1969 How is region P different from region Q? region P region Q A contains DNA loosely coiled around histone proteins contains DNA tightly coiled around histone proteins B is the site of RNA and polypeptide synthesis is the site of rRNA synthesis C is the site of ATP synthesis is the site of protein synthesis D has circular DNA has absence of DNA

3 © DHS 2022 9744/01 [Turn Over 2 The flow diagram shows a technique called cell fractionation used to separate cell organelles by their relative sizes. Cells are homogenised and mixed with buffer to prepare them for cell fractionation. The diagram shows the appearance of the homogenised cell mixture. Which organelle is found in sediment 3? A Nucleus B Mitochondria C Endoplasmic reticulum D Ribosome

4 © DHS 2022 9744/01 3 The figure shows the structure of s ophorose which is made up of two glucose monomers. Sigma-aldrich, 2022 Which of the following statements are correct? 1 It is a reducing sugar. 2 There is at least one beta glucose molecule present. 3 Polymerisation of sophorose forms cellulose. 4 The bond between the two monomers is a 1,6 glycosidic bond. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 4 Membrane fluidity affects membrane permeability. The more fluid a membrane is, the more permeable it is. Which of the following change in membrane structure increases the membrane permeability? A Increase in cholesterol level at low temperature B Decrease in cholesterol level at low temperature C Increase in hydrocarbon tail saturation level D Decrease in hydrocarbon tail unsaturation level

5 © DHS 2022 9744/01 [Turn Over 5 The figure shows the synthesis pathway of the amino acid s threonine, lysine, methionine and isoleucine, from the amino acid aspartate. The amino acids are underlined in the figure. The dotted lines and arrows represent feedback inhibition. Which action will result in an increase in methionine concentration? A Addition of lysine B Addition of aspartate semialdehyde C Addition of threonine D Addition of isoleucine

6 © DHS 2022 9744/01 6 The figure shows the change in quantity of components 1, 2 and 3 of an enzyme catalysed reaction within a fixed time, with varying incubation temperatures. Which row represents the components 1, 2 and 3? component 1 component 2 component 3 A substrate enzyme product B product substrate enzyme C product enzyme substrate D substrate product enzyme

7 © DHS 2022 9744/01 [Turn Over 7 The figure shows a short segment of a DNA molecule. created using biorender.com What is the sequence of the strand running in the 5’ to 3’ direction from top to bottom? A 5’ CTCAATG 3’ B 5’ AGACCGT 3’ C 5’ TCTGGCA 3’ D 5’ GAGTTAC 3’

8 © DHS 2022 9744/01 8 To synthesize DNA molecules in the laboratory, a student isolated and purified various molecules needed for DNA replication. She added them into a mixture and successfully obtained many DNA molecules. To study the role of each molecule in the process of DN A replication, the student performed a few set ups, each with one molecule removed from the mixture. She obtained the following results. set up result 1 A few DNA strands, with some short double stranded regions of DNA-RNA hybrid. 2 A few DNA molecules. 3 Many DNA strands with long stretches of double -stranded DNA regions. What molecule is removed in each set up? set up 1 set up 2 set up 3 A ligase DNA polymerase helicase B ligase helicase DNA polymerase C DNA polymerase ligase helicase D DNA polymerase helicase ligase

9 © DHS 2022 9744/01 [Turn Over 9 The diagram shows the results of the electrophoresis of DNA fragments from four members of a family, R, S, V, W and another male, X, who claims that he is the father of one of the child. Which bands indicate that R and S do not have the same set of parents? A 2 and 3 B 2 and 6 C 4 and 5 D 4 and 8

10 © DHS 2022 9744/01 10 The statements describe the process of conjugation between two bacteria cells. 1 F plasmid replicates semi-conservatively in donor cell 2 replication of F plasmid occurs to form double -stranded DNA in recipient cell 3 conjugation tube breaks and retracts 4 donor cell forms sex pilus 5 conjugation tube forms between two bacterial cells 6 single-stranded copy of F plasmid transferred into recipient cell Which order of events describe conjugation? A 4 → 5 → 1 → 6 → 2 → 3 B 4 → 5 → 6 → 1 → 2 → 3 C 5 → 4 → 1 → 6 → 2 → 3 D 5 → 4 → 6 → 2 → 1 → 3 11 The arginine (arg) operon is present in some bacteria to regulate the synthesis of the essential amino acid arginine. The operon consists of structural genes which code for the enzymes that synthesise arginine. The operon is switched off when arginine is in excess. Which statements are correct? 1 Excess arginine acts as the co-repressor which binds to the repressor. 2 The arg operon is negatively regulated. 3 The regulation of the arg operon is similar to that of the lac operon. 4 The synthesis of arginine is an anabolic process. A 1 and 3 B 2 and 4 C 1, 2 and 4 D 1, 2, 3 and 4