P6 Science SA1 2025 — Pei Chun

The table below shows three characteristics, A, B and C, of some animals. A tick (✓) shows that the characteristic is present. . What do A, B and C represent? (1) A=has wings, B=has scales, C=has legs; (2) A=has wings, B=lays eggs, C=has scales; (3) A=has feathers, B=has wings, C=has legs; (4) A=has feathers, B=lays eggs, C=has wings

Which of the following is not a form of response to changes? (1) A child grew taller over a year. (2) A snail hid in its shell when touched. (3) A pufferfish inflated its body when threatened. (4) A frog jumped into a pond when a snake approached.

Three animals are classified in the flowchart shown below. [Flowchart: Start → Question P? Yes → cockroach; No → Question Q? Yes → mealworm beetle; No → frog]. What are questions P and Q? (1) P=Does it have a 3-stage life cycle? Q=Does the adult have wings? (2) P=Does it have a 4-stage life cycle? Q=Does the adult have wings? (3) P=Does the young look like the adult? Q=Does it have a 3-stage life cycle? (4) P=Does the young look like the adult? Q=Does it have a 4-stage life cycle?

The diagram below shows the life cycle of a flowering plant. . Which of the following is correct? (1) M=fertilisation, N=pollination; (2) M=pollination and fertilisation, N=dispersal and germination; (3) M=dispersal, N=pollination and germination; (4) M=pollination and germination, N=fertilisation and dispersal

The diagram below shows two cells, P and Q. . Which of the following is correct? (1) Plant cell=P, Function of E=controls movement of substances in and out of the cell; (2) Plant cell=P, Function of E=gives the cell a shape; (3) Plant cell=Q, Function of E=controls movement of substances in and out of the cell; (4) Plant cell=Q, Function of E=gives the cell a shape

An experiment was set up as shown below. . What would happen to the drop of red ink after a while and what was the reason? (1) Moves left (towards seeds); seeds took in oxygen. (2) Moves right (away from seeds); seeds gave out oxygen. (3) Moves left; seeds took in carbon dioxide. (4) Moves right; seeds gave out carbon dioxide.

A student made three statements about sexual reproduction in plants and animals. A: The fertilised egg is found in the ovary. B: Reproductive cells are produced in the anthers. C: Fertilisation occurs in the female reproductive part. Which of the following is correct? (1) Plants=B, Humans=A,C; (2) Plants=A,C, Humans=A; (3) Plants=A,B,C, Humans=A,C; (4) Plants=A,B,C, Humans=C

The diagram below shows a pond habitat with some living things. . Based on the diagram above, how many populations of producers and consumers can be found in this habitat? (1) Producers=three, Consumers=three; (2) Producers=three, Consumers=four; (3) Producers=four, Consumers=three; (4) Producers=eleven, Consumers=eleven

The diagram below shows a food web in a habitat. . A large number of organism E was introduced into the habitat. E only feeds on one type of organism in this habitat. After some time, all the other organisms decreased in number. Which organism did E feed on? (1) A (2) B (3) C (4) D

The diagram shows an insect with several adaptations which help to protect it from predators. . A: It spreads its forelegs to appear bigger. B: It has feelers which help it to detect danger. C: It fans its wings to appear more threatening. Which of the adaptations are structural adaptations? (1) A only (2) B only (3) A and C only (4) A, B and C

The diagram shows a sealed container which holds 60 cm³ of water and 40 cm³ of air as shown below. 30 cm³ of water was removed from the container through the tap and 20 cm³ of air was then pumped in using the pump. . What would be the final volume of air in the container? (1) 20 cm³ (2) 60 cm³ (3) 70 cm³ (4) 80 cm³

Alex looks into a fish tank as shown. . Which statement explains why he can see the glass? (1) Light is reflected from the fish. (2) No light passes through the fish. (3) Light passes through the glass easily. (4) Some light is reflected from the glass.

Jamus attached 5 identical drops of wax on an oval-shaped metal wire. The metal wire was heated by a heat source for five minutes. . Which of the following shows the order that the drops of wax would drop off the metal wire? (1) A → E → D → C → B (2) A → B → E → C → D (3) B → C → D → E → A (4) B → A → E → C → D

Shriya had two beakers of water of different volumes but at the same temperature as shown below. She added all the water from beaker Y into beaker X. . The volume of water in beaker X increased to 300 ml. She measured the temperature of the water immediately. Which of the following correctly describes the water in beaker X? (1) Temperature increased, Amount of heat increased; (2) Temperature increased, Amount of heat remained the same; (3) Temperature remained the same, Amount of heat increased; (4) Temperature remained the same, Amount of heat remained the same

Substance P is a solid at 30 °C and a liquid at 100 °C. Which of the following is possible? (1) Melting point=20, Boiling point=110; (2) Melting point=20, Boiling point=90; (3) Melting point=50, Boiling point=110; (4) Melting point=50, Boiling point=90

Mary made two puddles on the floor as shown below with the same volume of liquids Y and Z. . Which of the following can Mary conclude from her experiment? (1) The size of the puddle affects the rate of evaporation. (2) The liquids from puddle Y and puddle Z evaporated at the same rate. (3) The liquid from puddle Y evaporated at a faster rate than the liquid from puddle Z. (4) The greater the surface area of the puddle, the faster the rate of evaporation.

Sean wanted to find out about conditions that affect the breeding of mosquitoes. He conducted an experiment and recorded the number of mosquito eggs that hatched in a day out of 30 eggs at different temperatures. He repeated the experiment two more times. His results are as shown. . (a) Based on his results, what can Sean conclude about the effect of temperature on the number of mosquito eggs hatched? [2] (b) Sean sprayed some oil on stagnant water in a well as shown below. [Diagram: a well filled with water; a layer of oil sits on top of the water]. Explain how this reduces the breeding of mosquitoes. [1]

Diagram 1 shows the fruit of plant E and its seeds. Diagram 2 shows plant E and its surrounding area. The seeds dispersed from plant E may fall in any of the two areas, A and B. [Diagram 1: a small splitting fruit with seeds scattering around it. Diagram 2: a tree with two zones either side of its trunk — A is the inner ring of ground directly around/under the canopy, B is the outer ring further away from the trunk]. (a) State the dispersal method for the fruits of plant E. [1] (b) An equal number of seeds fall in areas A and B. However, there are fewer young plants E growing in area A than in area B. Explain why this is so. [1] (c) The seed of plant E has a fleshy and sweet-tasting part attached to it as shown in the diagram below. . Ants will often carry the seeds of plant E back to their underground nest, which is a distance away from plant E. After feeding on the sweet-tasting part on the seed, the ant will move the seed to the waste pile in the nest. Ant droppings can be found in the waste pile. Explain how these actions of the ants help in the reproduction of plant E. [2]

Animal H is a mammal that lives in a hot place. It has predators that live on land and in water. . (a) During the day, animal H spends most of its time in the water. Suggest a benefit for animal H to stay in the water in the day. [1] (b) Animal H's nostrils are located near the top of its head as shown below. [Diagram: head of animal H with most of body submerged in water; only the top of head with nostrils above water]. Suggest an advantage of the position of the nostrils for the survival of animal H when it is in the water. [1] (c) Small insects that feed on blood are usually found on the bodies of large mammals. Bird P preys on these small insects. Bird P perches on the back of animal H and pecks at it as shown below. [Diagram: bird P standing on the back of animal H]. (i) Explain how bird P would benefit from its relationship with animal H. [1] (ii) Explain how animal H would benefit from its relationship with bird P. [1]

Joanna made the following observations of organisms, V, W, X, Y and Z. • Both V and W are plant eaters. • X is only the predator of Y. • V and W are the prey of Y. • Z gets its energy directly from the Sun. (a) Draw a food web to show the food relationships among all the organisms above. [2] (b) Organism W, which is brown in colour, frequently rests on a branch as shown below. . How does the appearance of organism W help in its survival? [1]

A beaker containing substance Q was left on a table. After one hour, the shape of substance Q changed as shown below. . (a) What is the state of matter of substance Q at the start of the experiment? [1] (b) Fahrid used a funnel to fill a bottle with substance Q as shown below. Substance Q dripped slowly into the bottle at first. [Diagram: funnel inserted snugly into the mouth of a bottle on the left; on the right, the funnel is lifted slightly above the mouth of the bottle with substance Q flowing in faster]. When he lifted the funnel slightly above the mouth of the bottle, he observed that substance Q flowed into the bottle at a faster rate. Explain his observation. [2]

Jacey has two similar plates made of materials X and Y. He shone a lamp on the plate made of material X and observed the shadow formed on the screen. . He then repeated the experiment with the plate made of material Y. The diagram below shows the shadows formed on the screen. [Diagram: shadow of plate made of material X is grey/lighter; shadow of plate made of material Y is fully black/dark]. (a) Based on his observations, state a property of materials X and Y. Material X: ____ Material Y: ____ [1] (b) Jacey set up another experiment as shown. The light sensor on the screen gave a reading of 30 units. [Diagram: lamp on left, wooden plate in middle, screen with light sensor on right; arrow shows an object moving along the surface of the table towards the lamp]. As Jacey moved an object along the surface of the table, the reading on the light sensor remained at 30 units and then dropped to 0 units suddenly. (i) Which object (lamp, wooden plate or screen) did Jacey move and in which direction? [1] (ii) Suggest why the reading on the light sensor dropped to 0 units. [1]

Joy took out a bottle of milk from the refrigerator and placed it on a table. A few minutes later, she observed that there were water droplets on the bottle of milk as shown in the diagram below. . (a) Explain how the water droplets were formed. [2] (b) Joy placed another bottle of milk from the freezer onto the table. After a short time, a thin layer of white solid was formed on the surface of the bottle. [Diagram: a bottle of milk taken from the freezer with a thin layer of white solid (frost) on its outer surface]. (i) Explain how the white solid was formed. [1] (ii) The white solid cannot be seen after a while. Explain why. [1]

Yimei conducted an experiment to find out which material, P or Q, is a better conductor of heat. She poured the same volume of hot water at 90 °C into two similar cups, made of materials P and Q. . Yimei placed the cups on a table in the classroom and measured the temperatures of the water in the cups at different times. Her results for the cup made of material P is shown below. [Graph: temperature of water (°C) vs time (min); curve starts at 90 °C, decreases steadily, then levels off at 30 °C]. (a) Explain why the temperature of the water in the cup made of material P decreased with time. [1] (b) Based on her results, Yimei concluded that material Q is a better conductor of heat than material P. Using a pencil, draw a line on the graph above to show how the temperature of the water in the cup made of material Q changed with time. [1] (c) Give a reason how each of the following actions helps make her experiment a fair test. (i) placing the cups at the same place [1] (ii) using cups of the same size and shape [1] [2]