Fuhua Pure Biology Prelim 2024 Paper 2

[Turn Over Candidate Name: Class: Index No.: FUHUA SECONDARY SCHOOL Secondary Four Express PRELIMINARY EXAMINATION 2024 4E Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School Fuhua Secondary School BIOLOGY 6093/02 Paper 2 Candidates answer on the Question Paper No Additional Materials are required. DATE 22 August 2024 TIME 1115 – 1300 DURATION 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. 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. FOR EXAMINER’S USE PARENT’S SIGNATURE Section A Section B Total /70 /10 /80 Setter(s): Mr Joshua Tan Vetter(s): Mr Owen Tan, Mr Nicholas Liu This document consists of 18 printed pages, including this page.

2 Section A Answer all questions. 1 Pectin, a type of carbohydrate, is one of the components of cell walls which are essential to maintaining the structure of plant cells. Tomatoes are firm when unripe but soften when ripening due to the hydrolysis of these cell wall components by enzymes , including polygalacturonase. The activity of polygalacturonase can be described as follows: pectin mono-galacturonate (a) Using the ‘lock and key’ hypothesis, describe the action of polygalacturonase. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. ………………………………………………………………………………………………. [4] The activity of polygalacturonase can be triggered by ethylene, which is released as a gas by some ripening fruits. An experiment was carried out to investigate the effect of spraying a liquid form of ethylene on the ripening of tomatoes. Table 1.1 records the concentration of ethylene used and the corresponding average number of days the tomatoes took to completely ripen. Table 1.1 concentration of ethylene / % average number of days tomatoes took to completely ripen 0 20 5 16 10 13 15 11 20 10 25 10 30 10 polygalacturonase

3 [Turn Over (b) Plot a graph of the results in Table 1.1. [4] (c) With reference to the graph in (b), describe and explain how polygalacturonase concentration affected the number of days the tomatoes took to completely ripen. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. ………………………………………………………………………………………………. [3]

4 (d) It is often advised that ripening bananas should not be placed together with other ripe fruits. Using the information provided in the question, suggest why this is so. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. ………………………………………………………………………………………………. [2] [Total: 13] 2 Fig. 2.1 shows the human alimentary canal. Fig. 2.1 (a) Name parts G and H. G ……………………………………… H ……………………………………… [2] (b) In which lettered part does most of the absorption of substances occur? ………………………………………………………………………………………………. [1]

5 [Turn Over (c) Auto-brewery syndrome (ABS) is a condition characterised by the conversion of carbohydrates into alcohol in the digestive tract by fungi or bacteria. This process, known as fermentation, can occur in anaerobic conditions. Individuals with severe ABS suffer from elevated blood alcohol levels, as well as symptoms usually associated with alcohol intoxication. Over time, these patients often experience liver failure. (i) Patients with ABS are advised not to drive. Explain why. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………….. [2] (ii) Suggest how patients with ABS can manage their blood alcohol levels to reduce the likelihood of liver failure. ……………………………………………………………………………………………… ……………………………………………………………………………………….. [1] [Total: 6] 3 Individuals with a condition known as autosomal dominant compelling helio -ophthalmic outburst (ACHOO) syndrome experience uncontrollable sneezing episodes whenever they are suddenly exposed to bright light. Various muscles contract during sneezing, including the diaphragm muscle, abdominal muscles, and muscles at the back of the throat. (a) Explain the nervous pathway when an individual with ACHOO syndrome is exposed to bright light and sneezes. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. ……………………………………………………………………………………………… [5]

6 (b) (i) A couple, both with ACHOO syndrome decided to have a child. The child was born without ACHOO syndrome. Use a genetic diagram to show how that is possible. Include a legend stating the letters representing each allele. [4] (ii) The couple decided to have another child. Calculate the probability that they will have a baby girl with ACHOO syndrome. probability ………………………… [2].. [Total: 11]

7 [Turn Over 4 A study investigated the probability of pregnancy resulting from sexual intercourse on specific days of the menstrual cycle. Fig. 4.1 shows the results of this study. Fig. 4.1 (a) (i) The study shows a probability of 20% that sexual intercourse three days before ovulation will result in pregnancy. State how many times more likely pregnancy is if sexual intercourse takes place two days later? ………………………… [1].. percentage probability of pregnancy / % days before ovulation

8 (ii) Explain the role of a named hormone in the menstrual cycle during the days investigated by this study. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. ………………………………………………………………………………………......... ……………………………………………………………………………………….. [2] (b) A woman smoked while she was pregnant. Explain how this will affect oxygen transport to the fetus. …………………………………………………………………………………………………….. …………………………………………………………………………………………………