YIJC 2023 H2 9744 P2 ANS

1 @YIJC 9744/02/PE/2022 [Turn over YISHUN INNOVA JUNIOR COLLEGE JC2 PRELIMINARY EXAM Higher 2 NAME INDEX NO CG BIOLOGY Paper 2 Structured Questions Candidates answer on the Question Paper. No Additional Materials are required. 9744/02 30 Aug 2023 2 hours READ THESE INSTRUCTIONS FIRST Write your name, index no. and CG on this cover page. Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use 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 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 At the end of the examination, submit booklets A, B and C separately to the invigilator. This document consists of 29 printed pages and 1 blank page. For Examiner’s Use Section A 1 10 2 10 3 8 4 10 5 10 6 12 7 10 8 10 9 10 10 5 11 5 Total 100 ANSWERS

2 @YIJC 9744/02/PE/2022 [Turn over Answer all questions 1 Fig. 1.1 shows an electron micrograph of a chloroplast. Fig. 1.1 (a) (i) On Fig. 1.1, use the letter X and a label line to identify where the light independent stage of photosynthesis occurs. Label stroma [1] (ii) Describe two ways in which the structure of the chloroplast is adapted for its function. 1 (fluid-filled matrix called) stroma contains reactants/substrates and enzymes required for Calvin cycle/ light independent reactions; 2 highly folded thylakoid membrane increase SA for embedding of photosynthetic pigments/ light harvesting complexes/ electron carriers of ETC/ ATP synthase for increased rate of light dependent reactions/ chemiosmosis/ photophosphorylation; 3 thylakoid membrane impermeable to H+ allow proton gradient to be set up across thylakoid membrane/ accumulation of H + in thylakoid space; [2] (iii) Chloroplasts and mitochondria both have double membranes. State two other structural similarities between chloroplast and mitochondria. 1 70S ribosomes; 2 Circular DNA; 3 Presence of ETC/ ATP synthase/ stalked particles/ proton pump on membranes; [2]

3 @YIJC 9744/02/PE/2022 [Turn over (b) Fig. 1.2 shows the relationship between CO 2 assimilation rate and increasing light intensity in a plant, when carbon dioxide concentration is not a limiting factor. Fig. 1.2 (i) Explain why the CO2 assimilation rate plateaus at high light intensity. 1 light saturation point has been reached at this point, maximum rate of chlorophyll a photoactivation is occu