2016 VJC H2 Biology Prelims Paper 2 Questions

1         VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION 2017 NAME : ____________________________________ CT CLASS : ____________________________________ H2 BIOLOGY 9744/2 Paper 2 Structured Questions 2 hours READ THESE INSTRUCTIONS FIRST Write your Name and CT Class on the cover page of this paper. Write in dark blue or blue pen. You may use a soft pencil for any diagrams or graphs. Do not use any staples, paper clips, highlighters, glue or correction fluid. Answer all questions in the spaces provided on the question paper. The use of an approved scientific ca lculator is expected, where appropriate. You may lose marks if you do not s how your working or if you do not use the appropriate units. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 19 printed pages, including cover page For Examiner’s Use 1 2 3 4 5 6 7 8 9 Total

2         1 Fig.1 shows an electron micrograph of an organelle. There are two distinct groups of vesicles (Boxes B and C) associated with this organelle. Fig. 1 Source:https://ib-biology2010-12.wikispaces.com/Cell+Images (a) (i) Identify Organelle A. Support your answer with one observable feature, other than vesicles, shown in Fig 1. Organelle A: [2]

3         (ii) Describe the differences in the role of the vesicles in Boxes B and C.             [4] In Angelman syndrome, a severe and rare neurodevelopmental disorder, it has been reported that the lack of ubi quitin protein ligase E3A ( UBE3A) expression leads to a disruption of structure and function of Organelle A. (b) Suggest how the lack of UBE3A expression can lead to a disruption in the structure and function of Organelle A. [3] (c) State two characteristics, one in structure and one in chemical property that you would expect to see in ubiquitin protein ligase. [2] [Total:11]

4         2 An experiment to determine the effect of Compound K, a metabo lite derived from ginseng, on the expression of a gene (RUNX3) was carried out using a culture of human colorectal cancer cells. RUNX3 gene codes for a transcription factor. Cells were treated with Compound K for 72 hour s. Samples of cells were removed at specific time intervals. These cells were then lysed and the mRNA and proteins analysed. Fig 2 shows the changes in the HDAC (Histone Deacetylase) mRNA and HDAC protein over the 72 hour period. The thickness of the band is an indication of the concentration of the mRNA and proteins. Fig 2 (a) Explain the similarity in the pattern seen