Integrated Science — Structured Questions Practice
Secondary 1 · structured questions
Prepared by Miss Clarissa Ng
www.clartutors.com
www.clartutors.com
Read the extract about Sungei Buloh Wetland Reserve.
Sungei Buloh Wetland Reserve is a 202-hectare mangrove reserve in the north-west of Singapore, gazetted as a nature reserve in 2002. Its mudflats, ponds and mangrove trees support a wide range of life. Each year, thousands of migratory shorebirds stop at the reserve to rest and feed on their journey between the Arctic and Australia. Otters, monitor lizards, mudskippers and horseshoe crabs are also found there. The reserve is a popular place for photography, birdwatching and school field trips, and its boardwalks are used by hikers. Keeping the mangrove forest intact also protects the coastline from erosion and keeps the water clean for the fish farms nearby.
(a)(i) There are five core values that humans place on biodiversity. State and describe two of these values, using the extract above. [2]
(a)(ii) State and describe one type of ecosystem service provided by the reserve. [2]
Using infrared spectroscopy, astronomers have measured the percentage composition by volume of the atmosphere of a planet 24.4 light years from Earth.
(a) Explain why this atmosphere would be harmful to human health. [1]
(b) Ozone is present in the upper atmosphere of the planet. State one advantage and one disadvantage of ozone. [2]
A beaker contains a mixture of sand and potassium nitrate solution.
(a) Draw a labelled diagram to show how the sand and the potassium nitrate solution can be obtained separately. [2]
(b) Describe how a dry sample of potassium nitrate crystals can be obtained from the filtrate collected in (a). [2]
(c) Read each statement below carefully. Circle TRUE if you think the statement is true, or FALSE if you think it is false. [2]
Fig. 4 shows cells observed in the leaf of a plant.
(a)(i) Identify the parts of the cells indicated by A and B. [2]
(a)(ii) Describe how B is adapted for its function in the plant. [2]
(b) Based only on the structures that can be seen in Fig. 4, state one way in which this cell is similar to an animal cell. [1]
(c) Explain the importance of division of labour in a living organism. [1]
(d) Cyanobacteria are prokaryotic cells that can photosynthesise and are often mistaken for plant cells. Describe how a cyanobacterium differs from the cell in Fig. 4. [2]
Fig. 5.1 shows a plane mirror fixed at the corner of a car park ramp. It lets a driver standing in the shaded area see a car approaching along the lane. The ray OA is the ray of light from the oncoming car that is incident on the mirror.
(a) Complete the ray diagram in Fig. 5.1 to show how the driver sees the image of the oncoming car in the mirror. Mark the position of the driver with an 'X' and the position of the image with the letter 'I'. [3]
(b) Other than removing blind spots, state one other application of reflection. [1]
A kingfisher hovers above a pond, looking down at a fish below the surface. The bird judges its dive by the light coming up from the fish, which bends at the water surface. Fig. 6.1 shows one ray of light travelling down from the kingfisher, entering the water at the surface and reaching the fish.
(a) Measure and record the angle of incidence and the angle of refraction in Fig. 6.1, both measured from the normal. [1]
(b) A second ray travels along the same path in the opposite direction, from the kingfisher in the air into the water, in Fig. 6.2. Complete Fig. 6.2 to show where the fish sees the image of the kingfisher. [2]
(c) The speed of light in the pond water is 2.26 × 10⁸ m/s. Calculate the refractive index of the water. Show your working. [1]
An incense stick burns in one corner of a room. The stick itself is a solid, and the smoke that rises from it is a mixture of vapour particles.
(a) Using the kinetic model of matter, explain the difference in the movement and the arrangement of the particles in the solid incense stick and in the smoke particles. [2]
(b) A bottle of air freshener holds a liquid. Explain, using the kinetic model of matter, why a liquid has a fixed volume but no fixed shape. [2]
(c) Using the idea of diffusion, explain why a person standing at the other end of the room can smell the incense. [1]
(a) Fill in the blanks in the table above. [2]
(b) Chlorine-35 is an isotope of chlorine-37. Define the term isotope. [1]
(c)(i) Calcium chloride is spread on roads to melt ice. Draw the dot-and-cross diagram of calcium chloride, CaCl₂. [1]
(c)(ii) Natural gas is mainly methane, CH₄. Draw the dot-and-cross diagram of methane. [1]
(c)(iii) Calcium chloride and methane have the same kind of formula ratio, XCl₂ and CH₄. Calcium chloride melts at 772 °C, while methane melts at −182 °C. With reference to structure and bonding, account for the difference in their melting points. [3]
(c)(iv) Solid calcium chloride dissolves in water to form a solution that conducts electricity. With reference to structure, explain why the solution conducts electricity. [2]
(c)(v) Unlike calcium chloride, graphite does not dissolve in water, yet it conducts electricity in the solid state. With reference to structure, explain how. [1]