2024 ACJC H2 Bio P1 QP

This document consists of 20 printed pages. Anglo-Chinese Junior College JC2 Biology Preliminary Examination Higher 2 BIOLOGY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet 9744/01 10 September 2024 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your Name and Index number in the Answer Sheet provided. There are thirty questions in this section. 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 Question Paper. The use of an approved scientific calculator is expected, where appropriate.

2 Anglo-Chinese Junior College 2024 J2 H2 9744 Paper 1 Preliminary Examination 1 Which statement is correct according to the principles of cell theory? A All organisms originate from a single cell. B Cells can carry out all necessary life processes independently. C Cells are the fundamental units of structure and function in all living organisms. D Multicellular organisms have cells that perform specialised functions. 2 Active transport is one of the key processes that occurs across the cell surface membrane. Without it, many other processes within the organism cannot occur. Which statements accurately describe the features of active tra nsport across a cell surface membrane? 1 It can move substances against th eir concentration gradients. 2 It relies solely on the diffusion process without any energy expenditure. 3 It involves the hydrolysis of ATP for energy. 4 It only occurs when the external concentration of the substan ce is higher than its internal concentration. A 1, 2 and 3 B 1 and 3 only C 2 and 4 only D 3 and 4 only 3 Which statement can explain how viruses challenge the concepts of what is considered living? A They are much smaller than most cells. B They can reproduce when they infect host cells. C They have enzymes which are not active outside a host cell. D They have their own genetic material which codes for viral proteins.

3 [Turn over Anglo-Chinese Junior College 2024 J2 H2 9744 Paper 1 Preliminary Examination 4 The diagram represents the structure of the human immunodeficiency virus (HIV). Which statements are correct for components V, W, X, Y and Z in HIV? 1 V, W, X and Z are only made o f amino acids while Y is made of ribonucleotides. 2 V and X are prevented from undergoing 3D conformational chang e when an inhibitor binds to CD4 receptor on host cell. 3 W protects the two identical positive-sense RNA molecules whi ch will be reverse transcribed by Z. 4 Y contains genes which code for proteins in HIV, including one that cleaves polyproteins into individual functional proteins. A 1, 3 and 4 B 1 and 2 only C 2 and 3 only D 3 and 4 only

4 Anglo-Chinese Junior College 2024 J2 H2 9744 Paper 1 Preliminary Examination 5 Pullulan is a polysaccharide. The diagram shows the repeating unit present in pullulan. Which row correctly identifies characteristics that are present in molecules of pullulan? OH group attached to the anomeric carbon is below the plane of the ring presence of 1,6 glycosidic bond A   key B    = true C    = not true D  

5 [Turn over Anglo-Chinese Junior College 2024 J2 H2 9744 Paper 1 Preliminary Examination 6 Reelin is a glycoprotein that plays a critical role in the deve lopment of the nervous system. Its structure and function can be influenced by various factors, including temperature and pH. The structural integrity of reelin is essential for its interaction with its receptors and subsequent signalling pathways. Which statements describe the effects of temperature or pH on reelin? 1 Increasing the temperature can cause partial unfolding of ree lin, exposing hydrophobic regions that can lead to aggregation and loss of function. 2 Decreasing the pH can result in protonation of amino acid sid e chains, disrupting ionic interactions and causing a conformational change in reelin. 3 Significant increases in tem perature above the optimum can improve the ability of reelin to interact with receptors by transiently exposing binding sites. 4 Changes in pH can lead to the ionisation of groups on the oli gosaccharides of reelin, thereby altering its stability and receptor binding affinity. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 7 An enzyme is known for its ability to cleave peptide bonds in p roteins. A specific region of this enzyme contains specific amino acid residues that interact with the peptide bonds in other proteins, allowing for precise cleavage. Which statement describes how other proteins bind to the enzyme for them to undergo precise cleavage? A Hydrophobic interactions between non-polar residues at the acti ve site of the enzyme promote enzyme-substrate binding, altering the overall energy change of the reaction. B Ionic interactions between polar residues at the active site of the enzyme and the protein substrate increase the rate of enzyme-substrate complex formation. C The protein substrate undergoes a change in 3D conformation, le ading to an induced-fit that adjusts the conformation of the active site of the enzyme. D The active site of the enzyme fo rms a complementary conformatio n that specifically accommodates the peptide bonds of the protein substrate.

6 Anglo-Chinese Junior College 2024 J2 H2 9744 Paper 1 Preliminary Examination 8 Enzyme-based biosensors in the food industry are used to analyse nutrients and detect natural toxins. They can also be used to determine the level of pesticides, proteins and fatty acids found in food. In a biosensor, enzymes are i mmobilised on the transducer. The products of the reaction will detach from the biosensor. The diagram shows how an enzyme mo lecule interacts with its sub strate (the analyte) in a biosensor. Which statement is consistent with the above information? A The enzymes can be reused before the products are removed. B The enzymes undergo a 3D conformational change that stimulates the transducer. C The substrates interact directly with the transducer and interfere with the reading. D The transducer detects the change in the concentration of the products. biological transducer No signal recognition (electrode) molecule (enzyme) analyte biological transducer Signal (substrate) recognition (electrode) molecule (enzyme) product 0.31 -----

7 [Turn over Anglo-Chinese Junior College 2024 J2 H2 9744 Paper 1 Preliminary Examination 9 Which statement is a common feature of rRNA, tRNA and mRNA? A They are made up of ribose sugars, nitrogenous bases and phosphate groups. B They are products of transcription and used as templates in translation. C They can form phosphodiester bonds between complementary bases. D They each have a 1:1 ratio of pyrimidine and purine bases. 10 Gemcitabine is a chemotherapy drug used in the treatment of can cer, such as bladder and breast cancer. Gem