2022 HCI JC2 H2 Biology Prelims Paper 3 QP

© Hwa Chong Institution 2022 9744 H2 Biology / JC2 Preliminary Examinations / Paper 3 HWA CHONG INSTITUTION JC2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 21S7 ___ CENTRE NUMBER INDEX NUMBER BIOLOGY Paper 3 Long Structured and Free-response Questions Candidates answer on the Question Paper. No Additional Materials are required. 9744/03 13 September 2022 2 hours INSTRUCTIONS TO CANDIDATES Write your name, CT group, Centre number and index number in the spaces at the top of this cover page. 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. INFORMATION FOR CANDIDATES 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. You are reminded of the need for good English and clear presentation in your answers. This document consists of 20 printed pages. For Examiners' Use 1 / 30 2 / 10 3 / 10 4 or 5 / 25 Total / 75

2 © Hwa Chong Institution 2022 9744 H2 Biology / JC2 Preliminary Examinations / Paper 3 BOOKLET I SECTION A Answer all the questions in this section. QUESTION 1 Tropical cone snails are small, slow -moving marine animals. They are carnivores, which hunt and kill prey that include fish. Fig. 1.1 shows two different hunting behaviours exhibited by cone snails. Both hunting behaviours use conotoxins that are made up of a cocktail of different types of proteins. The hunting behaviours include: ● taser-and-tether (TT), where electricity and conotoxins are discharged resulting in instantaneous immobilization of prey ● net-engulfment (NE), where a cloud of conotoxins is released to stun nearby fish and the muscular walls of the rostrum (false mouth) extends out to form a massive funnel to engulf multiple prey fish. taser-and-tether (TT) net engulfment (NE) Fig. 1.1

3 © Hwa Chong Institution 2022 9744 H2 Biology / JC2 Preliminary Examinations / Paper 3 (a) Suggest and explain which hunting method is more efficient. [3] The conotoxins bind to the membrane -bound receptors on the muscle cells in fish to immobilise them. (b) Suggest how a cocktail of proteins instead of a single protein is advantageous for the cone snail. [3] Insulin and ρ-TIA are two types of proteins commonly found in conotoxins. (c) Describe how insulin is able to trigger a response inside the muscle cell. [4]

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