2022 TJC JC2 H2 Biology Prelim P3 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. Section A Answer all questions in the spaces provided on the Question Paper. Section B Answer any one question in 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. The number of marks is given in the brackets [ ] at the end of each question or part question. TEMASEK JUNIOR COLLEGE 2022 JC2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER BIOLOGY 9744/03 Paper 3 Long Structured and Free Response Questions PART I 13 SEPTEMBER 2022 2 hours Candidates answer on the Question Paper. No Additional Materials are required. For Examiner’s Use 1 / 9 2 / 17 3 / 24 4 / 5 / 25 This document consists of 9 printed pages and 3 blank pages.

2 Section A Answer all questions in this section. 1 To investigate other conditions affecting rate of photosynthesis, two sets of plants, A and B, were grown from seeds at different concentrations of carbon dioxide: • A – normal atmospheric concentration of carbon dioxide (0.033%) • B – twice the normal atmospheric concentration of carbon dioxide (0.066%) The rates of photosynthesis at different light intensities for the two sets of plants were measured and shown in Fig. 1.1. Fig. 1.1 (a) With reference to Fig. 1.1, (i) describe and explain, in terms of limiting factors, the results from the plants in set A; [2] 1. QF: As light intensity increases from 0.5 to 6 a.u., mean rate of photosynthesis increases from 0 a.u. to 1.9 a.u. A: 5.4 – 7 a.u. for upper limit with correct y-axis values quoted 2. light intensity is main limiting factor 3. QF: As light intensity increases from 6 a.u. to 10 a.u., mean rate of photosynthesis remains constant / levels off / reaches plateau at 2 a.u. A: Continue from point 1 QF 4. Light intensity is not limiting, CO2 concentration is limiting Note: many students missed out the word “concentration” – the phrase “carbon dioxide is limiting” is not accurate - ½ if student used (a.u.) without abbreviating at the start of the answer since question did not abbreviate light intensity / arbitrary units mean rate of photosynthesis per unit area of leaf / arbitrary units

3 [TURN OVER Marker’s comments: Some students are still using phrases such as “increase at a fast rate / slow rate” – LAST REMINDER t