CJC Prelim H1 Bio P1 Ans

8876 / 01 / Prelim Examination / 2023 NAME: _________________________________________ CLASS: _________ INDEX: ___________ CATHOLIC JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS Higher 1 BIOLOGY 8876/01 18 September 2023 1 hour Additional Materials: Answer Sheet (Multiple Choice Optical Mark Sheet) READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name (as per NRIC), class, and index number on this booklet. Write and shade your name (as per NRIC) , NRIC / FIN number and class on the Answer Sheet (Multiple Choice Optical Mark Sheet) in the spaces provided. There are 30 multiple choice 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 shade your choice in soft pencil on the Answer Sheet (Multiple Choice Optical Mark 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. This document consists of 28 printed pages and 0 blank page. [Turn over SUGGETED ANSWERS

2 8876 / 01 / Prelim Examination / 2023 Answer all questions. 1 The diagram shows two electron micrographs of cells. F G Which organelles are visible in each of the cells F and G? Key: ✓ = visible  = not visible ANS: B cell chloroplasts nucleolus nucleus A F G  ✓ ✓ ✓  ✓ B F G  ✓ ✓  ✓ ✓ C F G ✓ ✓ ✓   ✓ D F G  ✓  ✓ ✓ ✓

3 8876 / 01 / Prelim Examination / 2023 2 Different chemical processes occur in different organelles in a plant cell. chloroplast mitochondrion ribosome phosphorylation oxidation translation polymerization transcription replication transcription reduction polymerization translation phosphorylation transcription How many rows in the table correctly show processes that occur in these three organelles? A 1 B 2 C 3 D 4 ANS: B 3 Three types of glycosidic bonds that occur between the carbon atoms of monosaccharides to form different polysaccharides are listed. 1, 2 (carbon 1 to carbon 2) 1, 4 (carbon 1 to carbon 4) 1, 6 (carbon 1 to carbon 6) Which row identifies the glycosidic bonds found in each of the molecules shown? amylose amylopectin cellulose glycogen A 1,4 1,2 and 1,6 1,6 1,4 and 1,6 B 1,4 1,4 and 1,6 1,4 1,4 and 1,6 C 1,4 and 1,6 1,4 and 1,6 1,4 1,2 and 1,6 D 1,6 1,4 1,6 1,2 and 1,6 ANS: B

4 8876 / 01 / Prelim Examination / 2023 4 The figure below is an electron micrograph of a pair of barrel-shaped centrioles that play an important role in organising microtubules that serve as the cell’s skeletal system. They help determine the locations of the nucleus and other organelles within the cell. Microtubules are assembled from a heterodimeric protein called tubulin, as shown in the diagram below. Which of the following explains why tubulin is considered a polymer as well as a monomer? why tubulin is a polymer why tubulin is a monomer A It is a macromolecule. It is a quaternary protein. B It is the building block of microtubule. It is made up of many amino acids. C It is made up of many amino acids. It is the building block of microtubule. D It has many α-helices and β-pleated sheets. It is made up of two different subunits. ANS: C microtubule α-tubulin β-tubulin centrioles

5 8876 / 01 / Prelim Examination / 2023 5 One way of representing fatty acid chains is Cx : y, where Cx is the number of carbon atoms and y is the number of double bonds. The table shows the percentage mass of eight different fatty acid chains in four cell membranes, 1, 2, 3 and 4. Cell Membrane percentage mass of each fatty acid chain C10 : 0 C12 : 0 C14 : 0 C16 : 0 C18 : 0 C18 : 1 C18 : 2 C18 : 3 1 1 2 2 21 35 29 2 1 2 2 23 19 45 3 1 3 2 3 23 21 43 4 4 1 2 4 22 2 52 11 1 Which of the following about the four cell membranes (1, 2, 3 and 4) is correct? Most fluid Least fluid A 1 2 B 2 3 C 3 4 D 4 1 ANS: D

6 8876 / 01 / Prelim Examination / 2023 6 The graph shows how the concentration of components of an enzyme -catalysed reaction changes with time. Which row is correct? enzymes with empty active sites substrates products enzyme-substrate complexes A 1 2 4 3 B 2 3 1 4 C 4 1 3 2 D 3 4 2 1 ANS: B

7 8876 / 01 / Prelim Examination / 2023 7 An experiment was carried out to investigate the digestion of starch using amylase at two different temperatures. A sample was removed from each mixture at 15 seconds intervals and placed onto a spotting tile well containing two drops of iodine in KI solution. The results are shown in the diagram. Which shows the correct temperatures and times for the complete digestion of starch? temperature / oC Time / s A 30 3.15 10 0.45 B 30 45 10 195 C 10 45 30 195 D 10 3.15 30 0.45 ANS: B

8 8876 / 01 / Prelim Examination / 2023 8 The graph compares the effect of temperature on the activity of the protease enzyme, papain, when in solution (free) and when immobilised in alginate beads. Which statement about the effect of immobilisation of papain is correct? A It increases the stability of papain at higher temperatures. B It alters the shape of papain’s active site at higher temperatures. C It decreases the activity of papain at higher temperatures. D It reduces the number of collisions of papain with the substrate. ANS: A

9 8876 / 01 / Prelim Examination / 2023 9 The diagram shows the fluid mosaic model of membrane structure. Which row gives possible functions for the numbered parts? 1 2 3 4 A barrier to polar molecules enzyme cell recognition regulates fluidity B cell recognition regulates fluidity barrier to polar molecules enzyme C enzyme cell recognition regulates fluidity barrier to polar molecules D regulates fluidity barrier to polar molecules enzyme cell recognition ANS: B

10 8876 / 01 / Prelim Examination / 2023 10 The diagram shows part of a cell surface membrane. The arrow shows the path taken by potassium ions when they diffuse through the membrane out of a cell. The graph shows how the rate of diffusion of potassium ions across the cell surface membrane is affected by the concentration of potassium ions within the cells. Which row is correct? region W to X: limiting factor on the rate of diffusion region Y to Z: limiting factor on the rate of diffusion A concentration of potassium ions inside the cell number of potassium channels B number of potassium channels concentration of potassium ions outside the cell C concentration of potassium ions inside the cells slower rate of potassium ions passing through the channels D concentration of potassium ions outside the cell minimum rate of potassium ions passing through the channels ANS: A intracellular region extracellular region potassium ions