2017 RVHS H2 Biology Prelims Paper 2 Answers

River Valley High School Pg 1 of 23 Year 6 H2 Biology 9744 Paper 2 2017 Preliminary Examination II RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION II CANDIDATE NAME CENTRE NUMBER S CLASS INDEX NUMBER H2 BIOLOGY 9744/02 Paper 2 Structured Questions 11 Sep 2017 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. Answer all questions 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. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 9 2 / 13 3 / 8 4 / 10 5 / 12 6 / 15 7 / 10 8 / 11 9 / 12 Total / 100 _____________________________________________________________________ This document consists of 24 printed pages.

River Valley High School Pg 2 of 23 Year 6 H2 Biology 9744 Paper 2 2017 Preliminary Examination II Answer all questions. 1 Fig. 1.1 shows an electron micrograph of part of a plant cell. Fig. 1.1 (a) Identify region A and state its function. [2] 1. Stroma (of chloroplast);; 2. Site of light independent reactions / Calvin cycle;; (b) Describe how the structure of the membrane at B allows it to perform its function. [3] 1. (S) Large surface area of thylakoid membrane; 2. (F) Holds photosystems for light absorption / ETC for transfer of electrons; 3. (S) Thylakoid membrane impermeable to H +; 4. (F) Allows proton gradient to be generated (for chemiosmosis); 5. (S) Contains ATP synthase; 6. (F) For phosphorylation of ADP to ATP / ATP synthesis. Cyanobacteria are prokaryotic cells that are capable of carrying out photosynthesis. The

River Valley High School Pg 3 of 23 Year 6 H2 Biology 9744 Paper 2 2017 Preliminary Examination II structure of a cyanobacteria is shown in Fig. 1.2. Fig. 1.2 (c) With reference to Fig. 1.1 and Fig. 1.2, compare the visible structures of cyanobacteria with that of C. [2] Similarities (1 max) 1. Both are bound by two membranes;; 2. Both have thylakoids;; Differences (1 max) Feature Chloroplast Cyanobacteria Grana Present Absent;; Intergranal lamellae Present Absent;; Cyanobacteria are considered to be the ancestors of structure C. They continued to function after being engulfed by primitive euk aryotic cells and evolved over time. This theory is known as the endosymbiont hypothesis. (d) State two features of structure C that provide support for this hypothesis. [2] 1. contains circular DNA;; 2. has 70S ribosomes;;