2018 VJC H2 Biology Prelims Paper 1 Questions

VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION 2018 NAME : ____________________________________ CT CLASS : ________ ____________________________ H2 BIOLOGY 9744/1 Paper 1 Multiple Choice 1 hour Additional material: Multiple choice answer sheet READ THESE INSTRUCTIONS FIRST Write your name, exam number on the answer sheet provided. Do not use any staples, paper clips, highlighters, glue or correction fluid. There are 30 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. 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 paper. The use of an approved scientific calculator is expected, where appropriate. This document consists of 17 printed pages, including cover page.

2 1 Which of the following is/are the most likely consequence(s) for an animal cell lacking functional Golgi bodies? 1. The cell dies because it is unable to ma ke glycoproteins to detect stimuli from its environment. 2. The cell dies from a lack of enzymes to digest food taken in by endocytosis. 3. The cell dies because of the accumulati on of worn-out organelles within itself. 4. The cell is unable to synthesis e centrioles for cell division. 5. The cell is unable to export it s enzymes or peptide hormones. A 1 and 5 only B 2, 3 and 4 only C All except 4 D All of the above 2 Which of the following options correctly matches the functional and structural features of cellulose, collagen, glycogen and triglycerides? Function Structure Linear/ Fibrous Molecule held together by hydrogen bonds Branched chains A Cellulose Support    Collagen Strengthening    B Cellulose Support    Triglyceride Storage    C Collagen Strengthening    Glycogen Storage    D Glycogen Storage    Triglyceride Storage   

3 3 Influenza virus has an enzyme called neuraminidase which breaks down glycoproteins in the membrane of the cell that the virus will infect. The glycoprotein binds to the active site of neuraminidase by induced fit. Which statements about the induced fit hypothesis of enzyme action are correct? 1. The active site must have a complem entary shape to the substrate for them to bind together. 2. This enzyme is less likely to be affe cted by non-competitive inhibitors than an enzyme working by the lock and key mechanism. 3. The substrate is converted to product by specific R-groups in the active site just like the lock and key mechanism. A 1 and 2 B 2 and 3 C 2 only D 3 only 4 An unusual enzyme has been found in a tropical grass. • It catalyses the hydrolysis of the f ungal polysaccharide, chitin, into amino sugars. • It also inhibits the activity of an en zyme in locust guts which catalyses the digestion of amylose. What describes the actions of this unusual enzyme? reaction catalysed reaction inhibited A hydrolysis of glycosidic bonds c ondensation of glycosidic bonds B hydrolysis of glycosidic bonds hydrolysis of glycosidic bonds C hydrolysis of peptide bonds condens ation of glycosidic bonds D hydrolysis of peptide bonds hy drolysis of glycosidic bonds

4 5 Bone marrow contains many stem cells. Some of these stem cells are responsible for the replacement of red blood cells. During the production of red blood cells, a series of changes occur to the cell structure. The fi gure below shows the production of a red blood cell from one of these stem cells. Which of the following correctly describes the changes that occur as cell X becomes a mature biconcave red blood cell? 1. displays cell surface antigens such as ABO, CD4 and CD8 2. becomes multipotent 3. synthesises haemoglobin and carbonic anhydrase 4. loses its nucleus 5. loses organelles such as ribosomes, ER, mitochondria 6. loses telomerase activity A 1, 2, 4, 6 B 2, 3, 4, 6 C 1, 3, 4, 5 D 3, 4, 5, 6

5 6 The sets of diagrams show four possible outcomes when an unlabelled molecule of DNA is allowed to replicate twice in the presence of 15N-labelled nucleotides. Labelled sections of DNA are represented by dotted lines. Which set of diagrams correctly shows the result of DNA replication?

6 7 The diagram shows the synthesis of a poly nucleotide. Molecule W is a nucleoside triphosphate. Which statements are correct? 1. The base in X could be the pyrimidine, uracil 2. The base in W could be the purine, adenine 3. The base in X is the pyrimidine, cytosine 4. The base in Y is the purine, guanine A 1 and 4 only B 2 and 3 only C 3 and 4 only D 1, 2, 3 and 4 8 Which statements correctly describe the structure and function of prokaryote ribosomes? 1. A prokaryote ribosome can accommodat e only one amino acyl-tRNA at a time. 2. Prokaryote ribosomes are smaller t han eukaryote ribosomes and sediment at 70 S. 3. In prokaryotes, ribosomes can begin translating mRNA before its synthesis has been completed. 4. In prokaryotes, ribosomes translate m RNA in the same cellular compartment in which it is transcribed. A 1 and 3 only B 1, 2 and 4 only C 2, 3 and 4 only D 1, 2, 3 and 4 - - - - hydrogen bond

7 9 The flowchart shows the classification of several regions of non-coding eukaryotic DNA, X, Y and Z. Which statement(s) correctly describes X, Y and Z? 1. Regions X and Y are made up of transcriptionally active tandem repeats. 2. Regions X and Y are always associated with proteins, but DNA at region Z is only associated with proteins during gene expression. 3. Region Z may involve DNA bending but region Y shortens during DNA replication. 4. Regions X, Y and Z are conserved throughout the life of the organism. A 2 only B 3 only C 1 and 4 only D 2 and 3 only 10 Which of the following statement comparing the human immunodeficiency virus (HIV) and lambda phage is incorrect? A The HIV enters by receptor-mediated endocytosis, but the lambda phage infects bacterial cells by injecting its DNA. B The capsid of the HIV enters the host ce ll, but the capsid of the lambda virus does not. C The genome of the HIV must be process ed before it is int egrated into the host chromosome, but the genome of the lambda virus can be directly integrated. D New HIV are released from the host ce ll via budding, but new lambda virus are released via cell lysis. non-coding DNA X Y Z allows for proper segregation of chromosomes prevents loss of genes regulates gene expression levels repeated sequence

8 11 The bacterium, Pneumococcus pneumoniae, forms two types of colonies whose cells are structurally different. Smooth (S) cells have thick outer capsules, but rough (R) cells lack this capsule. S cells cause the disease pneumonia. In 1928, Frederick Griffith found that: • when R cells were mixed with heat-kill ed S cells and the mixture injected into mice, some of the mice became infected and died. • living S cells with capsules coul d be isolated from these dead mice. • injection of heat-killed S cells alone or of living R cells alone did not cause disease in mice. What can be concluded from these three observations to explain what happened when R cells were mixed with heat-killed S cells? A A heritable genetic change occurred in the R cells. B R and S cells conjugated when mixed. C R cells were changed into S cells by transduction. D R cells were transformed by DNA from heat-killed S cells. 12 The onset of puberty is triggered when cells in the h