2018 RVHS H2 Biology Prelims Paper 3 Answers

1 River Valley High School Year 6 H2 Biology 9744 Paper 3 2018 Preliminary Examination RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION CANDIDATE NAME CENTRE NUMBER S CLASS INDEX NUMBER BIOLOGY 9744/03 Paper 3 Long Structured and Free-response Questions 14 Sep 2018 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, index number and name in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Section A Answer all questions in the spaces provided on the Question Paper. Section B Answer any one question in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 1 / 25 2 / 25 Section B / 25 Total / 75 _____________________________________________________________________ This document consists of 19 printed pages and 1 blank page.

2 River Valley High School Year 6 H2 Biology 9744 Paper 3 2018 Preliminary Examination Section A Answer all the questions in this section. 1 Plant tissue culture is a technique to produce an entire plant using undifferentiated meristem cells. A cluster of meristem cells can be extracted and stimulated with growth hormones to differentiate to form different types of cells that give rise to an entire plant. (a) Suggest why meristem cells from any part of a plant can be used to produce the entire plant in plant tissue culture. [2] 1. The meristem cell contains all the DNA/genes/genetic material of the plant. 2. The meristem cell is totipotent.

3 River Valley High School Year 6 H2 Biology 9744 Paper 3 2018 Preliminary Examination In plant tissue culture, plant hormones are added to the meristem cells to regulate growth and differentiation to form roots and shoots. These hormones include auxin and cytokinin. The experiment set up is shown in Fig. 1.1 Fig. 1.1 The effects of various compositions of auxin and cytokinin on the cluster of meristem cells are summarised in Table 1.1. Table 1.1 Concentration of auxin / mg L -1 Concentration of cytokinin / mg L-1 Observation 0 0 10 0 8 4 6 6 4 8 0 10

4 River Valley High School Year 6 H2 Biology 9744 Paper 3 2018 Preliminary Examination (b) With reference to Table 1.1, state three conclusions on the effect of auxin and cytokinin on plant growth and differentiation. [3] 1. Both auxin and cytokinin are required for cell divisio