ASRJC 2023 JC2 H2 Biology Prelims Paper 1 (QP Ans)

ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P1 [Turn over 2023 JC2 PRELIMINARY EXAMINATION BIOLOGY 9744/01 PAPER 1 20 SEPTEMBER 2023 MULTIPLE CHOICE WEDNESDAY 1 HOUR Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and identification number on the MCQ Answer Sheet. 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. 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 scientific calculators is expected, where appropriate. This document consists of 19 printed pages and 1 blank page. H2 ANDERSON SERANGOON JUNIOR COLLEGE HIGHER 2

2 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P1 1 The electron micrograph shows a section of a cell in which several different organelles are found. Which statements correctly describe the labelled regions of the cell? 1 Organelles P, Q and R are present in all cells in a single plant. 2 DNA replication occurs in organelles P, Q and R. 3 Transcription and translation occur in organelles P and Q but not R. 4 Organelles P, Q and R use ATP in reactions that occur within them. A 1 and 2 only B 1 and 3 only C 2, 3 and 4 only D 1, 2, 3 and 4

3 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P1 [Turn over 2 In the life cycle of a fern, there is an alternation between haploid and diploid stages: • sporophyte stage where the plant is diploid and releases spores • gametophyte stage where the plant is haploid and releases gametes How many principles of the cell theory does the life cycle above show? A 0 B 1 C 2 D 3

4 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P1 3 The energy for bond formation in polysaccharides is provided by uridine triphosphate (UTP) instead of ATP. The stages involved in the formation of a glycosidic bond during cellulose synthesis include: 1 binding of an activated monosaccharide to the active site of a glycosyltransferase enzyme 2 release of UDP (uridine diphosphate) and water 3 the formation of a UDP-glucose complex releasing inorganic phosphate 4 reaction between a hydroxyl group of β-glucose and a UDP-glucose complex 5 reaction between a hydroxyl group of β-glucose and UTP What is the sequence of these stages? A 3  1  5  2  4 B 5  3  1  4  2 C 5  1  3  2  4 D 3  5  4  1  2 4 Three artificial cells of equal sizes, each surrounded by a partially permeable membrane, contain equal masses of different food reserves. One cell contains only fats, one cell contains only glycogen and one cell contains only glucose. Which of the following shows the rate of expansion of these cells when immersed in distilled water, and their energy content? (The sign ≈ means approximately equal and the sign > means greater than.) rate of expansion of cells respiratory energy content A glucose ≈ glycogen > fats fats > glycogen ≈ glucose B glucose ≈ glycogen > fats fats ≈ glycogen > glucose C glucose > glycogen > fats fats > glycogen ≈ glucose D glucose > glycogen > fats fats ≈ glycogen > glucose

5 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P1 [Turn over 5 Detergent molecules have a similar structure to phospholipids, consisting of a phosphate - containing group and a hydrophobic tail. When channel proteins extracted from cell membranes are mixed with a detergent solution, the detergent molecules cluster around the surfaces of the channel proteins that are shaded grey in the figure below. Which statement explains the orientation of detergent molecules when they cluster around the surfaces of the channel protein that are shaded grey in the figure? A The phosphate -containing groups of the detergent molecules are attracted to the shaded surfaces of the channel protein. B The tails of the detergent molecules cannot form hydrogen bonds with water or other polar molecules. C The shaded surfaces of the channel protein repel the hydrophobic tails of the detergent molecules. D The shaded surfaces of the channel protein and the phosphate -containing groups of the detergent molecules are polar.

6 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P1 6 The enzyme hexokinase which catalyses the transfer of a phosphate group from ATP to glucose, changes shape during the reaction, as shown in the diagram. Which statements are correct? 1 The reaction illustrates the ‘lock and key’ hypothesis of enzyme action. 2 ATP is a competitive inhibitor of hexokinase. 3 The active site for ATP is formed only in the presence of glucose, therefore binding of glucose to enzyme also allows ATP to bind. 4 In absence of glucose, ATP is not hydrolysed to release a phosphate group. A 1 and 3 B 1 and 2 C 2 and 4 D 3 and 4 7 Which of the following statement(s) is/are true regarding blood stem cells and cancer cells? 1 Both are able to move from one location in the body to another. 2 Both are found in cancer patients. 3 Both are unspecialised cells which can differentiate further. 4 Both are capable of indefinite replication. A 4 only B 1 and 3 C 2 and 4 D 1, 2 and 4

7 ASRJC BIOLOGY DEPT 9744/2023/J2PRELIMS/P1 [Turn over 8 Which statements about complementary base pairing are correct? 1 Purines contain more atoms than pyrimidines. 2 The base pairs are of the same length. 3 Cytosine forms a triple bond with its complementary base. 4 It allows amino acid activation to occur. A 1 and 2 B 1 and 3 C 3 and 4 D 2, 3 and 4 9 Polypeptide synthesis is based on sequences of three nucleotides, each specific for an amino acid. Which row shows the correct nucleotide sequences for an amino acid? nucleotide sequence of non-transcribed DNA strand mRNA codon tRNA anticodon A GGT CCA GGU B GGG CCC CCC C CCG CCG GGC D CCT CCU CCU 10 The diagram shows the first six codons of an mRNA molecule and amino acids for which they encode. AUG — AAG — UGU — UAU — CUC — AUG methionine lysine cysteine tyrosine leucine methionine As a result of a mutation, a dipeptide was produced instead of the normal polypeptide. The triplets on the DNA strand that is complementary to mRNA that code for ‘stop' are ATT, ATC and ACT. Which statement explains the production of a dipeptide?