DHS 2023 Y5 H2 Promo Paper 2

© DHS 2023 9744/02 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Promotional Examination Year 5 H2 BIOLOGY 9744/02 Paper 2 Section A Structured Questions 26 September 2023 Paper 2 Section B Long Structured and Free-Response Questions 1 hour 30 minutes READ THESE INSTRUCTIONS FIRST: Write your class, index number and name 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. Sections A and B 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 Paper 1 MCQ 15 Paper 2 Section A 1 9 2 11 3 7 4 8 Section B 1 15 2 15 Total 80 This document consists of 16 printed pages and 2 blank pages.

2 © DHS 2023 9744/02 Section A: Structured Questions Answer all questions. Question 1 Fig 1 is an electron micrograph of part of a eukaryotic cell. Fig 1 (a) Both the Golgi body and the rough endoplasmic reticulum are part of the network of membranes inside cells. Outline the structural features shown in Fig 1 that identify G as the Golgi body and not the rough endoplasmic reticulum. [2] (b) Calculate the actual diameter, X–Y, of the mitochondrion labelled in Fig 1. Write down the formula that you will use to make your calculation. Give your answer to the nearest whole nanometre (nm). formula Actual diameter = nm [2]

3 © DHS 2023 9744/02 [Turn over (c) Many of the cell structures in Fig 1 are surrounded by membranes. Membranes are approximately 6 nm to 7 nm wide. (i) Using your knowledge on fluid mosaic model , describe the structure of membranes. There is space below for a diagram. [3] (ii) The inner membrane of the mitochondrial envelope is much less permeable than the outer membrane. Suggest two ways in which the structure of the inner membrane of the mitochondrion may differ from that of the outer membrane to produce a less permeable inner membrane. [2] Total: [9]

4 © DHS 2023 9744/02 Question 2 Fig 2.1 shows a polypeptide molecule during protein synthesis. A molecule of glycine is shown just before it is added to the polypeptide. The product formed is incomplete. Fig 2.1 (a) (i) Complete Fig 2.1 to show how the products are formed. [3] (ii) Nam