VJC 2021 H2 Bio 9744 P1 QP

VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION 2021 HIGHER 2 NAME : ……………………………………………………….………………. CT CLASS: ………………..……… BIOLOGY Paper 1 Multiple Choice 9744 / 01 24/09/2021 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write your name and class on the Answer Sheet in the spaces provided. WRITE and SHADE your EXAM 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 24 printed pages. [Turn over]

1 1 The electron micrograph shows three cell organelles X, Y and Z. Which of the following statements about organelles X, Y and Z is/are true? 1 If a metabolic poison is introduced into the cell, only the function of organelles Y and Z will be disrupted. 2 Organelles Y and Z have more than one type of RNA associated with them. 3 In the absence of organelle X, the fluidity of the membrane will not be regulated. A 1, 2 and 3 B 1 and 3 only C 2 and 3 only D 2 only

2 2 The table compares the structure and function of some biomolecules. Structure Function Polymer Storage Structural Starch 1 2 3 Cellulose 4 5 6 Triglyceride 7 8 9 Phospholipid 10 11 12 Which combination of numbers links the four biomolecules to their correct structures and functions? A 1, 2, 4, 6, 8 and 12 B 1, 3, 5, 8, 10 and 11 C 2, 4, 6, 7, 8 and 11 D 3, 4, 6, 8, 10 and 12 3 Which roles of the cell surface membrane result from the properties of the phospholipids?

3 4 Adult human haemoglobin typically consists of two α chains and two β chains. Approximately 5% of humans have one amino acid in the β chain that has been changed. This change affects the structure and stability of haemoglobin. Which levels of protein structure could be affected in the haemoglobin with the changed amino acid? A primary only B primary, secondary and tertiary only C secondary, tertiary and quaternary only D primary, secondary, tertiary and quaternary 5 The decomposition of hydrogen peroxide to water and oxygen is catalysed by the enzyme catalase. During an investigation, 2 cm 3 of catalase was added to 20 cm3 of hydrogen peroxide and the volume of oxygen released was collected at intervals over a period of time. Which bar chart shows the result of this investigation?

4 6 Under normal metabolism, alcohol is broken down in the liver by the enzyme alcohol dehydrogenase to acetaldehyde, which is then converted by the enzyme acetaldehyde dehydrogenase to a harmless acetic acid derivative. Disulfiram is a drug used to support the treatment of alcoholism. It is a specific enzyme inhibitor of acetaldehyde dehydrogenase. In the presence of disulfiram, the Michaelis -Menten constant (Km) for acetaldehyde dehydrogenase increases. In the presence of disulfiram , alcohol consumed can only be partly broken down, resulting in nausea and vomiting. Why is it important that the enzyme inhibitor disulfiram is specific? 1 It cannot disrupt other metabolic pathways. 2 It prevents alcohol from binding to the active site. 3 It is unlikely to cause unwanted side effects. 4 It binds to an allosteric site of acetaldehyde dehydrogenase. A 1, 2, 3 and 4 B 1, 2 and 3 only C 1 and 3 only D 2 and 4 only

5 7 The diagram shows the relationship between the different potency of stem cells. Which of the following options describes the potency of stem cells found in 1 - 3? 1 2 3 A differentiate into any cell type to form the whole organism differentiate into limited range of cells and tissues appropriate to their location differentiate into almost any cell type to form any organ or type of cell B differentiate into limited range of cells and tissues appropriate to their location differentiate into almost any cell type to form any organ or type of cell differentiate into any cell type to form the whole organism C differentiate into any cell type to form the whole organism differentiate into almost any cell type to form any organ or type of cell differentiate into limited range of cells and tissues appropriate to their location D differentiate into almost any cell type to form any organ or type of cell differentiate into any cell type to form the whole organism differentiate into limited range of cells and tissues appropriate to their location 8 Bacteria were cultured in a medium containing heavy nitrogen ( 15N) until all the DNA was labelled. These bacteria (generation 1) were then grown in a medium containing only normal nitrogen (14N) for two generations (generation 2 and 3). The percentage of cells containing 15N in each generation was estimated. What will be the percentage of cells containing 15N in generations 2 and 3? Percentage of cells containing 15N Generation 2 Generation 3 A 100 100 B 100 50 C 50 50 D 50 25

6 9 The diagram below shows some of the molecules involved in translation. They are not drawn to scale. diagram not drawn to scale Which of the following statements is true? A Molecule 1 may contain the elements carbon, hydrogen, nitrogen, oxygen and phosphorus. B The amino acids in the active site of molecule 2 lowers the activation energy by increasing the reactivity of the groups involved in peptide bond formation. C Molecule 3 will allow the addition of water molecule to hydrolyse the peptide bonds in the polypeptide. D Bond 4 is formed from the carboxyl group of His with the amino group of Arg.

7 10 A polypeptide has the amino acid sequence glycine – arginine – lysine – serine. The table gives possible tRNA anticodons for each amino acid. Which sequence of bases on DNA would code for the polypeptide? A CCACGCAAGAGC B CCTTCCTTCTCG C GGAAGGAAAAGC D GGTTGGTTGTGC 11 DNA-RNA hybrids are formed by using the mature mRNA for a given gene that is expressed in both the pituitary gland and adrenal gland. The molecular weight of the proteins translated from the mature mRNA from both glands differ by 20%. It was observed that certain regions of the DNA remained as single stranded while others form double stranded with the mRNA. Based on the information provided, which of the following statements is true? A The number of single stranded DNA regions formed in DNA-RNA hybrid for pituitary gland is the same as that for the DNA-RNA hybrid for the adrenal gland. B The number of double stranded regions formed in DNA -RNA hybrid for pituitary gland is the same as that for the DNA-RNA hybrid for the adrenal gland. C The double stranded DNA -RNA regions formed can be made up of both exons and introns. D The single stranded DNA regions formed in DNA-RNA hybrid may contain exons.

8 12 Which of the following statements is not an advantage of the lysogenic cycle to the lambda phage virus? A A stable mode of continued perpetuation of viral DNA is guaranteed. B Viral DNA is replicated whenever the bacteria undergo binary fission. C Many copies of the phage DNA are replicated within the same host cell. D High numbers of prophage can be obtained as bacteria reproduce rapidly. 13 The electron micrograph below shows Escherichia coli undergoing a certain process. Which of the following is important for the proc