ACSI 2023 Y2 IP Life Sciences Final Examination

FINAL EXAMINATION 2023 YEAR TWO IP/SBGE LIFE SCIENCES Thurs 5 Oct 2023 1 hour 30 minutes Additional material: Multiple Choice Answer Sheet Soft pencil & eraser READ THESE INSTRUCTIONS FIRST Write your index number in the space provided at the top of the Question Paper. Section A Answer all questions on the Multiple Choice Answer Sheet (OTAS) provided. Write and shade your index number on the Answer Sheet in the spaces provided. Section B & Section C Answer all questions in the spaces provided on the Question Paper. At the end of the examination, submit the Multiple Choice Answer Sheet and the Question Paper separately. INFORMATION FOR STUDENTS Electronic calculators may be used. The intended number of marks is given in brackets [ ] at the end of each question or part question. This paper consists of 24 printed pages, including the cover page. INDEX NUMBER Anglo - Chinese School (Independent) FOR EXAMINER’S USE Section A / 30 Section B / 30 Section C / 20 Total / 80 Name of Parent / Guardian: Signature & Date:

2 Section A (30 marks) Answer all the questions on the Multiple Choice Answer Sheet (OTAS) provided. 1. Figure 1 illustrates (a) the formation of a normal binding (b) a competitive inhibition of a substrate-enzyme reaction. Figure 1 Which of the following statements is a false description of the processes shown in Figure 1? A. In normal binding, the substrate fits into the active site of the enzyme. B. In normal binding, the substrate forms an enzyme-substrate complex. C. In competitive inhibition, the inhibitor blocks the enzyme at the active site. D. In competitive inhibition, the inhibitor does not fit into any part of the active site. 2. Figure 2 shows the various modes of cellular transport through a cell membrane. Figure 2

3 Which one of the following accurately identifies the various modes of cellular transport illustrated in Figure 2 ? P Q R S A Active Transport Passive Transport Simple Diffusion Facilitated Diffusion B Facilitated Diffusion Active Transport Passive Transport Simple Diffusion C Simple Diffusion Facilitated Diffusion Active Transport Passive Transport D Simple Diffusion Passive Transport Facilitated Diffusion Active Transport 3. Root hair cells are able to absorb substances from the soil via the various modes of cellular transport. Which of the following statements is true? A. Nitrates are absorbed through active transport. B. Oxygen is absorbed through osmosis. C. Phosphates are absorbed through diffusion. D. Water is absorbed through active transport. For questions 4 and 5, refer to the information below. An investigation was conducted to find out the effects of using a particular fertilizer on the number of leaves grown by plants. The fertilizer only contained nitrates and potassium salts. Plants in G roup 1 were grown in soil with the fertilizer, whereas those in Group 2 were grown in soil without any fertilizer. The results of the investigation are shown in Figure 3 below. Figure 3

4 4 W hat deficiency symptom would the leaves of plants in Group 1 show even though they were given the fertilizer mentioned above ? A. Burned margins and purplish veins B. Interveinal chlorosis C. Light green / yellow leaves D. Older leaves appear black 5. Plants in Group 2 have spindly, yellow stems and they exhibit stunted growth. Which one of the following can be added to the soil f or Group 2 plants to reduce these deficiency symptoms? A. Boron B. Chloride C. Nitrate D. Phosphate For Questions 6 & 7, refer to Figure 4. Figure 4 6. Which of the following options correctly states what happens when the seed shown in Figure 4 was soaked in water for a suitable duration in preparation for germination? I. Food stored in part I dissolved in water. II. Parts G and H could not grow after being soaked in water. III. Part J was softened and fell off the seed. IV. The seed should have been kept dry for successful germination. A. I & II only. B. I & III only. C. I, II & III only. D. I, II, III & IV.

5 7. If conditions had been ideal for germination, which of the following statements is incorrect in describing the progress of the embryo in Figure 4 if the seed undergoes epigeal germination? A. H grows downwards into the soil. B. In G, the epicotyl grows rapidly before the hypocotyl. C. I is pulled out of the soil. D. I shrinks as the seedling continues to develop. 8. Figure 5 shows an open hydroponic system. Figure 5 Which of the following is the most significant reason if the seedling does not grow well in the set up? A. Instead of a sponge, the seedling should be supported by a growth medium. B. There should be at least 2 seedlings in the set up, instead of only one. C. The transparent container encourages algal growth in the nutrient solution. D. There is no air stone in the nutrient solution. 9. Which of the following are advantages of the aeroponics system? I. The plants are not affected by diseases. II. The plant roots are not waterlogged as they are well aerated. III. There is no need for checking and monitoring of the system. IV. It is possible to cool the solution economically for growing temperate crops. . A. I & III only B. II & IV only C. I, II & III only D. I, III & IV only

6 10. Figure 6 shows structures found in the walls of xylem vessels. Figure 6 State the name and function of the structures labelled Y. name function A lamina waterproofing the walls B lignin strengthening the walls C perforations allowing water to flow out of the walls D pits connecting to the phloem 11. Figure 7 shows an experiment conducted on a plant. Figure 7 A healthy plant is cut off as shown, leaving only the roots and stump of the plant in the soil. The glass tube attached to the stump shows the water level at the beginning and end of the experiment. What does this experiment demonstrate? A. active transport B. capillary action C. root pressure D. transpiration

7 For Questions 12 & 13, refer to Figure 8. Figure 8 12. Name the structure X in Figure 8. A. root hair B. root protrusion C. root vacuole D. root zone 13. Which of the following statements about the root hair cell is incorrect? A. It absorbs water and mineral salts from the soil. B. It contains a large plant vacuole. C. The cell sap in the vacuole has a low water potential. D. The root hair cell is dead as there is no protoplasm in it. 14. Which of the following statements illustrate the importance of a double circulation in humans? I. Blood flows faster in the pulmonary circuit than in the systemic circuit. II. Carbon dioxide diffuses efficiently into the air sacs of the lungs. III. N utrients are delivered to the body tissues quickly. I V. Oxygen is delivered to the body tissues efficiently. A. I & II only B. I & III only C. II & III only D. II, III & IV only

8 For questions 15 and 16, refer to the photomicrograph in Figure 9 below which shows components of human blood. Figure 9 15. Identify component B. A. Blood B. Lymph C. Plasma D. Tissue fluid 16. Which of the following statements are false for components A and C? They I. are more in numbers compared to component D. II. have a large or multilobed nucleus. III. help to transport antibodies in the blood. IV. protect the body against invasive pathogens. A. I & II only B. I & III only