DHS 2023 Y5 H2 Promo Paper 1

© DHS 2023 9744/01 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Promotional Examination Year 5 H2 BIOLOGY 9744/01 Paper 1 Multiple Choice Questions 26 September 2023 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 14 printed pages. For illustration only: A student from class 5C41, with index number 01, should shade “4101”. 4 1 0 1

2 © DHS 2023 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 Which statements are true for both region P and region Q? 1 Both contain DNA tightly coiled. 2 Both are the sites of RNA synthesis. 3 Both are the sites of ATP synthesis. 4 Both have circular DNA. A 1 and 2 B 2 and 3 C 3 and 4 D 1, 2 and 4

3 © DHS 2023 9744/01 [Turn Over 2 The flow diagram shows a technique called cell fractionation used to separate cell organelles by their relative size s. Cells are homogenised and mixed with buffer to prepare them for cell fractionation. The diagram shows the appearance of the homogenised cell mixture. Which organelles are found in liquid 1? A Nucleus B Mitochondria C Nucleus and endoplasmic reticulum D Mitochondria, endoplasmic reticulum, and ribosome

4 © DHS 2023 9744/01 3 Which statements about the differences between phospholipids and triglycerides are false? 1 Phospholipids have hydrophobic regions but triglycerides do not. 2 The fatty acids in a triglyceride are always saturated but the fatty acids in a phospholipid may be saturated or unsaturated. 3 Phospholipids contain phosphoester bonds but triglycerides do not. 4 Phospholipids are non-polar but triglycerides are polar. A 1 and 2 B 2 and 3 C 3 and 4 D 1, 2 and 4 4 Cellulose is a molecule responsible for providing mechanical support in plant cells. Some properties of cellulose are described as follows: 1 Alternate g lucose monomers are rotated, instead of residues being arranged in the same orientation. 2 Only one type of monomer is found in cellulose. 3 Cellulose is unable to interact well with water. 4 Numerous cellulose chains are bundled together via extens ive hydrogen bonds. Which properties account for starch being suitable as an energy storage molecule? A 3 and 4 B 1, 2 and 3 C 1, 3 and 4 D 2, 4 and 5

5 © DHS 2023 9744/01 [Turn Over 5 In a chemical reaction, reactants R and S are converted into products T and U. The graph shows the energy levels of these molecules over time. Which statements can be concluded from the graph? 1 The value of activation energy is shown by X. 2 The value of activation energy is shown by Y. 3 An enzyme has been added to the reaction mixture. 4 An enzyme helps to lower the activation energy by proximity effect. 5 R and S have lower energy than T and U. A 1 and 3 B 2 and 5 C 1, 3 and 4 D 2, 3, 4 and 5 Y

6 © DHS 2023 9744/01 6 The molecular structures of two nucleotides, X and Y, are shown in the diagram. The base in each nucleotide is adenine. Which statements are true about nucleotides X and Y? 1 X is an adenosine monophosphate and forms two hydrogen bonds with its complementary nucleotide during transcription. 2 X is a deoxyribonucleotide and forms a complementary base pair with a uracil nucleotide during transcription. 3 X is found in RNA and Y forms two hydrogen bonds with its complementary nucleotide during transcription. 4 Y is found in DNA and forms a complementary base pair with a uracil nucleotide during replication. A 1 and 2 B 1 and 3 C 2 and 3 D 1, 3 and 4

7 © DHS 2023 9744/01 [Turn Over 7 Bacteria grown in 15N medium for many generations were transferred to 14N medium to replicate for two generations . DNA from the bacteria was extracted and separated by density gradient centrifugation. Their results are summarised in the diagram below. What percentage of DNA strands consist of 15N and 14N after two generations in 14N medium? Percentage of DNA containing 15N 14N A 0 100 B 12.5 87.5 C 50 50 D 25 75

8 © DHS 2023 9744/01 8 Polymerase Chain Reaction (PCR) is the main molecular technique to detect HIV in a patient using a HIV test-kit. Which statement explains why the development of HIV test-kit was only possible after the genome sequence of HIV was available? A The sequence of the genome of HIV mutates very frequently. B DNA sequences flanking the target gene must be known to enable the synthesis of primers flanking the target DNA sequences. C The temperature s used for denaturation stage, annealing stage, and extension stage during PCR are determined by the genome sequence of HIV. D PCR is not error -free. The information on the genome sequence of HIV will ensure that no contamination will be present in the sample.

9 © DHS 2023 9744/01 [Turn Over 9 The diagram shows the results of electrophoresis of DNA fragments from three members of a family and another person named John , who claims that he is the biological father of the son. Autoradiography produced the following band patterns: Which bands indicate that the husband is the father of the son and not John? A 1 and 4 B 3 and 6 C 2 and 7 D 4 and 6 John

10 © DHS 2023 9744/01 10 The mRNA codons for amino acids are shown. A mutagen causes the adenine in DNA to pair with cytosine during transcription. Which tripeptide is synthesised when the DNA fragment 3’ ACCGTCAAT 5’ is used in protein synthesis in the presence of this mutagen? A proline-valine-proline B arginine-glutamine-proline C tryptophan-glutamine-leucine D threonine-valine-asparagine