NYGH 2015-S3EOY-Bio P2

Class Register Number Name 南洋女子中学校 NANYANG GIRLS’ HIGH SCHOOL End-of-Year Examination 2015 Secondary Three BIOLOGY Paper 2 Theory Paper 1 hour 45 minutes Tuesday 6 October 0930 - 1115 Additional materials: Writing papers READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, register number and class in the spaces at the top of this page and on any separate answer paper used. Write in dark blue or black pen on both sides of the paper. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A (40 marks) Answer all questions. Write your answers in the spaces provided on the question paper. Section B (30 marks) Answer all questions including questions 7, 8 and 9 Either or 9 Or. Write your answers on the separate writing paper provided. At the end of the examination, 1. fasten all your work securely together; 2. tick 9 Either (for Either) or 9 Or (for Or) next to the question number 9 in the grid below to indicate which question you have answered. INFORMATION FOR CANDIDATES You are advised to spend no longer than one hour on Section A and no longer than 45 minutes on Section B. The number of marks is given in the brackets [ ] at the end of each question or part question. The use of an approved scientific calculator is expected, where appropriate. Examiner’s Use Section A Section B 7 8 9 Either 9 Or Total Setters: BKoh & AMak This document consists of 15 printed pages. NANYANG GIRLS’ HIGH SCHOOL [Turn over

2015 End-of-Year Examination Secondary Three 2 Nanyang Girls’ High School Biology /II Section A Answer all questions. Write your answers in the spaces provided. 1 (a) Fig. 1.1 is an electron micrograph which shows part of a cell. Fig. 1.1 (i) Identify X. [1] (ii) Z is part of a nucleus. Identify Z. [1] (iii) State the functions of Y. [2] X Z Y

2015 End- of-Year Examination Secondary Three 3 Nanyang Girls’ High School Biology /II [Turn over (b) Fig 1.2 shows a plant cell. The cell has a magnification of 10 250 X. Fig 1.2 (i) Measure the length of the cell from P to Q (marked by two crosses). [1] Answer = (ii) Calculate the actual length of the cell from P to Q. Show your working and express your answer to the nearest whole number, in micrometres (μm). (1 metre = 100 centimetres = 1 000 000 micrometres) [2] Answer = [Total: 7] X X Q P

2015 End-of-Year Examination Secondary Three 4 Nanyang Girls’ High School Biology /II 2 (a) (i) State one similarity and one difference between endocytosis and exocytosis. [2] (ii) Give an example of endocytosis. [1] (iii) Give an example of exocytosis. [1] (b) Samples of red blood cells were placed in a series of sodium chloride solutions of different concentrations in different containers . After 3 hours, the samples were examined to determine the percentage of cells which had burst. The results are shown in Fig. 2.1. Fig. 2.1 100 90 80 70 60 50 40 30 20 10 0 0.32 0.34 0.36 0.38 0.40 0.42 0.44 0.46 0.48 0.50 sodium chloride concentration / g 100cm -3 percentage of red blood cells burst / %

2015 End- of-Year Examination Secondary Three 5 Nanyang Girls’ High School Biology /II [Turn over (i) Using Fig. 2.1, dete rmine the concentration of the sodium chloride solution which resulted in the bursting of all the red blood cells. [1] (ii) If cells from a carrot are to be placed in the same range of sodium chloride solutions, predict the percentage of cells burst and e xplain your answer. [2] [Total: 7] 3 (a) List two characteristics of enzymes. [2] (b) Describe one similarity and one difference between the lock-and-key hypothesis and the induced fit hypothesis of enzyme action. [2]

2015 End-of-Year Examination Secondary Three 6 Nanyang Girls’ High School Biology /II (c) Fig. 3.1 shows the energy profile diagram for a chemical reaction. Fig. 3.1 On Fig. 3.1, draw a graph, in blue pen, to show the energy profile diagram for an enzyme-catalysed reaction. [1] [Total: 5] 4 Lactase is widely used in the production of dairy products. (a) Give two reasons for converting lactose to glucose and galactose using lactase in dairy products. [2] (b) Laboratory experiments show that when the enzyme lactase is mixed with lactose, the initial ra te of reaction is highest at 48 ° C. In food processing, lactase is used at a muc h lower temperature, often at 5 ° C. Suggest two advantages of using lactase at low temperatures. [2] [Total: 4]

2015 End- of-Year Examination Secondary Three 7 Nanyang Girls’ High School Biology /II [Turn over 5 (a) Fig. 5.1 represents a transverse section through a leaf at 200X magnification. Fig. 5.1 (i) State two differences between cell X and cell Y. [2] (ii) Fig. 5.2 shows a cross section of part of a fig leaf . The two arrows indicate a pair of guard cells. Fig. 5.2 Suggest how X helps the plant to reduce water loss. [2] cell X cell Y X

2015 End-of-Year Examination Secondary Three 8 Nanyang Girls’ High School Biology /II (b) A potted plant was destarched by placing it in the dark for two days. It was then placed in a set -up shown in Fig. 5.3 and left under the sun to test a factor necessary for photosynthesis. Fig. 6.3 (i) How is the use of soda lime different from potassium hydroxide? [1] (ii) Suggest a suitable control that can be set up for this experiment. [2] (c) Some weed killers stop the plant from photosynthesi sing. These are often applied to the soil where the weeds are growing. Explain how the weed killer reaches its site of action in the leaves. [2] [Total: 9] bell jar soda lime potted plant potassium hydroxide solution polystyrene bag wrapped around the pot Fig. 5.3

2015 End- of-Year Examination Secondary Three 9 Nanyang Girls’ High School Biology /II [Turn over 6 (a) Fig. 6.1 shows an internal view of the human heart. Fig 6.1 (i) Use a blue pen to show the path of deoxygenated blood into and out of the heart in Fig 6.1. [1] (ii) Some babies are born with a disorder known as patent ductus arteriosus. This disorder results in a condition in which the hole between the aorta and the pulmonary artery fails to close after birth. This causes the baby to have poor growth and a shortness of breath. Predict how the blood circulation of a baby with this disorde r will be affected. [1] (iii) Explain why babies with this disorder may have poor growth. [1]

2015 End-of-Year Examination Secondary Three 10 Nanyang Girls’ High School Biology /II (b) Fig 6.2 shows an external view of the human heart. A blockage was detected at X. Fig 6.2 (i) Suggest one cause of such a blockage. [1] (ii) If the blockage continues at X, predict what will happen to this person. [2] (c) At rest, the rate of blood flow to the heart is 240 cm 3 per minute. During exercise, this rate ris