2015 RI H2 Biology Prelims Paper 2 Questions

© RI 2015 Preliminary Examination 9648/02 [Turn over RAFFLES INSTITUTION 2015 Year 6 Preliminary Examination Higher 2 BIOLOGY 9648/02 Paper 2 Core paper 16th SEPTEMBER 2015 2 hours Additional materials: Answer Sheet READ THESE INSTRUCTIONS FIRST Write your index number, CT group & name on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Section B Answer either ONE question. At the end of the examination, hand in your essay SEPARATELY. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 24 printed pages. CIVICS GROUP CANDIDATE NAME INDEX NUMBER 5 S 0 3 1 Raffles Institution Internal Examination For Examiner’s Use Section A 1 / 9 2 /10 3 /12 4 /10 5 /10 6 / 9 7 / 9 8 /11 Section B 9 or 10 /20 Total /100

2 © RI 2015 Preliminary Examination 9648/02 For Examiner’s Use Section A Answer all the questions in this section. 1 Meristematic root tissue from a barley seedling wa s prepared and its chromosomes we re observed under a microscope. Fig. 1.1 shows a cell from the root tissue at the metaphase stage of mitosis. Fig. 1.1 Fig. 1.2 shows the changes in amount of DNA at different stages of the barley life cycle. Fig. 1.2 (a) Mark out clearly with an arrow, , on Fig 1.2, the part of the graph which corresponds to the stage shown in Fig. 1.1. [1] (b) With reference to Fig. 1.2, state which of the stages, from A to D, (i) has/have the same number of chromosomes as shown in Fig. 1.1; [1]

3 © RI 2015 Preliminary Examination 9648/02 [Turn over For Examiner’s Use (ii) has/have a different number of chromosomes as shown in Fig. 1.1. [1] (c) Explain how stages in Y lead to variation. [4] (d) Explain the significance of the event occurring at X. [2] [Total : 9]

4 © RI 2015 Preliminary Examination 9648/02 For Examiner’s Use 2 Fig. 2.1 shows DNA replication. (a) (i) Use an arrow to show the direction of replication of the leading strand in the box provided in Fig. 2.1. [1] (ii) What do 5’ and 3’ on the DNA molecule represent? [2] (iii) Name the following molecules. [1] V: W: (iv) Describe the role of two named enzymes that are required for DNA replication. [2] (a) (i) V W Fig