2022 TJC JC2 H2 Biology Prelim P2 ANS

1 [TURN OVER READ THESE INSTRUCTIONS FIRST Write your Center 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 any working or if you do not use appropriate units. TEMASEK JUNIOR COLLEGE 2022 JC2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER BIOLOGY 9744/02 Paper 2 Structured Questions 23 AUGUST 2022 2 hours Candidates answer on the Question Paper. No Additional Materials are required. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 9 2 / 9 3 / 11 4 / 7 5 / 8 Answer all questions. This document consists of 11 printed pages and 1 blank page.

2 Answer all questions. 1 Muscle cells are known to store large amounts of glycogen that act as glucose reserves when blood glucose concentration is lower than the homeostatic range. Fig 1.1 shows an electronmicrograph of a part of a muscle cell. Fig. 1.1 (a) Outline structural features shown in Fig 1.1 that identify G as the Golgi body and not the rough endoplasmic reticulum (rER). [2] Note: There are 2 parts to this question – (1) what distinguishing features of G are, AND (2) why NOT rER, which will require comparison with rER. 1. G consists of separate / not interconnected flattened, curved membraneous sacs whereas rER consists of flattened sacs connected to one another. ½ m – if no mention of separate vs interconnected Marker’s comments: Many students missed out the word “flattened” in point 1 or only mentioned the word ‘cisternae’ without describing what it means. 2. The surface of G is smooth whereas the surface of rER is rough. OR Ribosomes absent on G whereas ribosomes present on rER. AVP: The outer membrane of nucleus envelope is not continuous with G whereas it is continuous with the membrane of rER (idea of continuity with nucleus; R: connected to nucleus). Max 1 m if no mention / comparison with rER (basically merely stating the features of G and not addressing the second part of the question)

3 [TURN OVER (b) Describe how the function of G and rER are linked. [2] 1. Ribosomes located on the surface of rER synthesise polypeptide chains which are inserted into the lumen / both organelles involved in formation of lysosomes / secretory vesicles 2. Polypeptide chains will