2019 EJC Promo JC1 P2 Bio (A)

©EJC 2019 9744/02/J1H2PromotionalExamination/2019 [Turn over EUNOIA JUNIOR COLLEGE JC1 Promotional Examinations 2019 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 1 9 - REGISTRATION NUMBER H2 Biology Paper 2 Structured Questions & Free Response Questions 9744/02 04 October 2019 2 hours Candidates are to answer all questions in section A in this question booklet. READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. There are two sections in Paper 2, section A and B. Answer all questions. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use paper clips, highlighters, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 17 printed pages and 1 blank page. For Examiner’s Use Section A 1 2 3 4 Section B 5 Total 80

2 ©EJC 2019 9744/02/J1H2PromotionalExaminations/2019 For Examiner’s Use BLANK PAGE

3 ©EJC 2019 9744/02/J1H2PromotionalExaminations/2019 [Turn over] For Examiner’s Use Section A Answer all the questions in this section. 1 Fig.1.1 is an electron micrograph of an animal cell. Fig 1.1 (a) (i) Identify the organelles A and B shown in Fig 1.1. A: __________________ B: __________________ [2] (ii) Compare the structures of both organelles. ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ .........................................................................................................................................[3] B A

4 ©EJC 2019 9744/02/J1H2PromotionalExaminations/2019 For Examiner’s Use Protons are transported across the inner mitochondrial membrane through a transport protein depicted in Fig 1.2. This transport protein also serves as an enzyme that drives the synthesis of ATP from ADP and an inorganic phosphate ion (Pi). Fig 1.2 (b) Using Fig. 1.2, (i) identify the type of transport protein. ........................................................................................................................................[1] (ii) state and describe the process by which protons are transported across the inner mitochondrial membrane. ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ .........................................................................................................................................[3] [Total: 9] H + H + H + H + H + H + H + H + H + H + H + H + H + ADP + Pi ATP

5 ©EJC 2019 9744/02/J1H2PromotionalExaminations/2019 [Turn over] For Examiner’s Use 2 Fig 2.1 shows an error occurring during the second meiotic division of primary spermatocytes of an unknown animal. Fig. 2.1 (a) (i) Complete Fig 2.1 to show the correct structures and number of chromosomes within the gametes. [1] (ii) Describe and explain how the error depicted in Fig 2.1 may have occurred. ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ........................................................................................................................................[3] Meiosis I Primary spermatocytes (2n) Meiosis II Gametes Secondary spermatocytes (n)

6 ©EJC 2019 9744/02/J1H2PromotionalExaminations/2019 For Examiner’s Use Testis cells undergo several rounds of mitosis to differentiate into primary spermatocytes. Fig 2.2 shows the different phases of the cell cycle. Arrows indicate checkpoints of the cell cycle, and brief descriptions of the G1 and G2 checkpoint criteria are given. The M checkpoint occurs during metaphase of mitosis. Fig. 2.2 (b) (i) State the criteria for the cell to pass the M checkpoint. ............................................................................................................................................ ........................................................................................................................................[1] (ii) With reference to Fig 2.2, describe how the dysregulation of cell cycle checkpoints could lead to cancer. ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ............................................................................................................................................ ........................................................................................................................................[3] G2 M S G1 G2 checkpoint: • DNA replication is completed • cell size is adequate G1 checkpoint: • cell size is adequate • sufficient nutrients and growth factors • absence of DNA damage

7 ©EJC 2019 9744/02/J1H2PromotionalExaminations/2019 [Turn over] For Examiner’s U