P6 Science SA1 2025 — Nanyang

Which of the following statements are true? A All living things depend directly on plants for food. B The Sun is the main source of energy for all living things. C Energy is transferred from the Sun to plants during photosynthesis. D Only water, oxygen and sunlight are needed for a plant to make food.

Minah wanted to find out how a plant affects the amounts of gases in its surroundings at different times of a day. She placed the set-ups in a well-lit garden as shown below. She measured the amount of two different gases in the container, Gas C and Gas D as shown in the graph below. [Figure: graph of Amount of gas (units) vs Time from 7 a.m. to 12 noon. Gas C line is high and slightly rising; Gas D dashed line is much lower and slightly falling.] Which one of the following would most likely be correct?

Alani conducted an experiment in a dark room to find out how the amount of light affects the rate of photosynthesis. He used a device to count the number of bubbles produced by the water plant in three minutes. Then he added a sheet of paper between the lamp and the water plant and counted the number of bubbles produced. He repeated this step until a total of 6 sheets of paper were used. Which of the following graphs correctly shows his most likely observations?

The diagram below shows a habitat. Based on the diagram above, which one of the following statements is correct?

The diagram below shows a pond and the organisms living in it. The organisms depend on each other for survival. Which one of the following statements correctly describes how the organisms benefit from each other?

The graph below shows how the number of fishes in a pond community changed over a period of six months. The fishes in the pond feed on the water plants. What are the likely reasons for the change in the number of fishes in the pond? W From A to B, the birth rate of fishes was equal to its death rate. X From A to B, the number of animals feeding on the fishes increased. Y From B to C, water plants were removed from the pond. Z From B to C, several organism X were added and they competed for food with the fishes.

Hugo found the following organisms in a forest. Which of the above organism(s) is/are decomposer(s)?

Study the food web below. Which of the following about living things J to O in the food web above is correct?

The food chain below shows the food relationship between four organisms in a community. flowering plant → butterfly → bird → snake. Based on the food chain above, which one of following graphs shows the change in population of flowering plant and snake after the number of birds increased in the community?

Amin observed the relationships between five types of organisms, P, Q, R, S and T, from the same community. He classified four of the types of organisms in the table below. Which one of the following food webs would most likely represent the relationships between the organisms in the community?

The table below shows the state of three substances X, Y and Z at different temperatures. Based on the information above, which of the following statements are correct? A Substance X has the lowest boiling point. B Substance Y has the highest melting point. C Substance X has a lower freezing point than substance Z.

Jessica left a beaker of ice on the table for 1 hour. After which, 50ml of boiling water was added into the beaker and it was left on the table for 3 hours. She recorded the changes in its temperature as shown in the graph below. Which part(s) of the graph show(s) ice/water increasing in temperature?

The diagram below shows the fruit of plant A. Which of the following statements about the flower that fruit of plant A came from are correct? P The flower has many ovaries. Q The ovary of the flower contains many ovules. R The seeds are formed when male reproductive cells fuse with the ovary. S The flower undergoes pollination and fertilisation before fruit A developed.

Anisah removed the food-carrying tubes of a plant at position Z as shown in the diagram below. The plant was watered daily. Which of the following are possible observations of the plant after a few weeks? A The leaves at position V remained green. B The flowers at position W cannot get water. C The fruit at position X grew bigger and juicer.

Which of the following shows the correct comparison of gases that we breathe in and out?

Three people were trapped in the lift where no air can enter and leave. The diagram below shows the composition of four different gases in the lift at the start. Which of the following correctly shows the composition of gases in the lift after 1 hour?

The diagram below shows the human digestive system. Which of the following correctly identifies the parts where digestion of food takes place?

Lindsey wanted to classify the four plants shown below. Which one of the following questions can be used to classify the plants above into two groups?

Which one of the following does not involve energy conversion?

Mdm Leong used an electric toaster to toast some bread as shown in the diagram below. When the bread was toasted, she observed hot mist rising from the bread and she heard a sound from the toaster. Which of the following shows the correct energy changes that took place at different parts of the set-up?

June set up an experiment to find out how the number of turns of a toy affects the distance moved by the cube as shown below. The distance moved by the cube was measured and recorded in the table shown below. [Table: 0 turns → 0 cm; 1 turn → 4 cm; 3 turns → 12 cm; 5 turns → 23 cm.] Based on the aim and results of the experiment above, which one of the following conclusions is correct?

The diagram below shows a ball rolling down a slide until it stopped at Z. Which of the following describes the energy possessed by the ball at the different positions? A From X to Y, kinetic energy of the ball increased. B The ball had less kinetic energy at Z than at Y. C From Y to Z, potential energy of the ball decreased. D The moving ball possessed no potential energy at Y.

The diagram below shows Alan throwing a basketball towards the basketball hoop. Which of the following describes the effect of the force Alan exerted at the start?

When constructing buildings, concrete blocks must be pushed into the ground by heavy weights as shown in the diagram below. The weight is lifted by a machine and then released to hit the concrete block. Which of the following would enable the weight to push the block deeper into the ground? A Use a weight of greater mass. B Apply oil on the bottom of the weight. C Raise the weight to a greater height before release. D Move the weight closer to the concrete block before release.

Pete was looking at a painting which was hung behind a wall through a hole as shown in the diagram below. Which of the arrows show the correct direction of light rays that enabled Peter to see the painting?

Brandon cut out some shapes from a piece of cardboard as shown below. The shapes had the same height and width. He then hung the shapes in a straight line at positions D, E and F as shown in the diagram below. [Figure: a torch on the left next to a wall, three shapes hanging at positions D (nearest the torch), E (middle), and F (nearest the screen), and a screen on the right.] The following shadow was cast on the screen. [Figure: a shadow 6 cm tall showing a triangle on top of a circle on top of a square outline — the overall shadow looks like a circle (largest), with a triangle peak above and a square base below; total 6 cm.] Based on the shadow formed, which of the following shows the correct positions of the shapes in the set-up above?

Different volumes of hot water at 80°C were poured into four identical containers. Which one of the following containers will contain the lowest amount of heat?

When railway tracks are built, gaps are left between them to allow for expansion of the tracks so that they would not be damaged. Each section of the railway track, part X, is of the same length. There should be a wide enough gap between one part X and another part X. Which one of the following information would be most useful to a person building the railway tracks?

The diagram below shows organism P. The young of organism P feeds on leaves. Alina conducted an experiment to find out the effects of the surrounding temperature and the amount of water vapour in the air on the number of eggs hatched by organism P over a period of time. The graphs below show the results of her experiment. [Figure: Graph 1 — Number of eggs hatched vs Surrounding temperature (°C): rises from 0 to a peak at about 20°C then falls to 40°C. Graph 2 — Number of eggs hatched vs Amount of water vapour (units): rises steadily from 0 to about 60 units, then levels off up to 100 units.] (a) Based on the results above, suggest the conditions needed for Alina to ensure the most number of eggs hatched over a period of time. Give a reason for your answer. [2] (b) Organism P lays its eggs, which hatch into larvae, on the leaves of plants. The larvae grow in size after some time. Explain how laying its eggs on leaves increases the chances of survival of organism P's young. [1]

The diagram below shows the food relationships among the different organisms in a tank. (a) Identify the food producer from the table above. [1] (b)(i) State the organism(s) that would be directly affected when the population of T decreased significantly. [1] (b)(ii) Explain how the organism(s) in (b) would be affected. [2]

Jeyna took a box of frozen meat out from the freezer. Soon, she observed a thin layer of ice forming on the package as shown in the diagram below. (a) Explain how a thin layer of ice had formed on the packaging of the box after it was taken out from the freezer. [2] (b) After a short while, Jeyna noticed that the thin layer of ice had disappeared. Explain what had happened. [1]

Darren had two fruits, P and Q, as shown below. (a)(i) State the dispersal method of Fruit P. [1] (a)(ii) State the dispersal method of Fruit Q. [1] Darren counted the number of young plants, K and L at various distances from their parent plants. The results are shown below. [Figure: bar chart with two bars per distance for Plant K (white) and Plant L (shaded). At distances nearer the parent plant Plant L (shaded) has many young plants while Plant K (white) has fewer; further away Plant K has more.] (b) Which fruit, P or Q belongs to plant K? Explain why. [2] (c) Based on the diagrams above, state an advantage of Plant L's dispersal method over plant K's dispersal method. [1]

Two celery stalks were placed in red-coloured water as shown below. The colour of the leaves was then observed after three hours. (a) State the aim of the experiment. [1] (b) After three hours, the leaves of both stalks were stained red. Describe how the red-coloured water could get to the leaves. [1] The stem of the thick celery stalk was then cut. The cut section of the stem is shown below. Tube X turned red but tube Y did not. [Figure: cross-section of celery stem showing two types of tubes labelled X (turned red) and Y (did not turn red).] (c) Identify tube Y and state its function. [1]

The graph below shows the changes in Mirabel's heart rate over time when she went running. (a) Based on the graph, describe the changes in her heart rate during the 15 minutes. [1] (b)(i) Suggest how Mirabel's activity changed after point S. [1] (b)(ii) Explain how the change in her heart rate based on your answer in (i). [1]

Andrew observed three cells, P, Q and R, under the microscope. He recorded his observations in the table below. A tick (✓) indicates the presence of the part of a cell. (a) Based on the table, is cell R from the leaf or from the root of a plant? Give a reason for your answer. [1] (b)(i) State another common cell part between cells P, Q and R that is not stated in the table above. [1] (b)(ii) Describe the function of the cell part in (b)(i). [1]

The graph below shows the amount of digested food in various parts of the digestive system after a girl had a meal. (a) Which part(s) of the digestive system produce(s) digestive juices? [1] (b)(i) Describe and explain the changes in the amount of digested food in the small intestine, between points P and R. From point P to point Q. [1] (b)(ii) From point Q to point R. [1]

Charles had a toy as shown in the diagram below. The top pair of wings could be turned to wind up a rubber band in the centre. He turned the wings a few times before releasing the toy into the air at the starting point marked on the ground. He observed that the wings turned noisily and the toy moved for a short while before falling to the ground. Charles then repeated what he did, increasing the number of times he turned the wings each time. [Figure: a boy releasing the toy; distance d is measured from the starting point to where the toy lands.] He measured the distance the toy travelled and recorded his results in the table below. [Table: Number of turns — 5, 10, 15, 20, 25, 30; Distance d (cm) — 25.3, 41.7, 58.1, 75.0, 75.2, 75.2.] (a) Which part of the toy provided the source of energy that made it work? [1] (b) State the main energy conversion in the toy when it was released. [Figure: energy diagram — potential energy → [energy] + [energy] + [energy], with toy before release on left and toy after release on right.] [1] (c) Based on the results shown above, what was the relationship between the distance moved by the toy and the number of turns made to the wings? [2] (d) Without making changes to the toy, suggest one way that Charles could make his results more accurate. [1]

(a) What is a force? [1] Mabel set up an experiment. She glued the spring to the table as shown below. She then attached a steel block on the spring. The length of the compressed spring was 10cm. (b) State the force(s) acting on the steel block. [1] Mabel then removed the 500g steel block and attached a 500g wooden block. (c) What would Mabel observe about the length of the spring? Explain her observation. [2] Finally, she replaced the wooden block with a 500g object X. She observed that the length of the compressed spring was 6 cm. (d) Suggest what object X could be. [1]

The diagram below shows a paper counting system that is made up of a light source, a light sensor and a datalogger. Paper P is placed at an equal distance between the light source and the light sensor. The light sensor measures the amount of light passing through the paper. The graph below shows the number of sheets of paper P and the amount of light recorded by the light sensor and datalogger. [Figure: graph of Amount of light detected (units) vs Number of sheets of paper P. Starts at 2550 units (0 sheets), drops sharply through 1, 2, 3 sheets, levels off close to 0 by 5 sheets.] (a) Based on the results above, state the maximum number of sheets Alexis should use to make a strong bag that still allows her to see the shapes of the items in the bag. [1] (b) Give a reason the amount of light decreases as the number of sheets increases. [1] (c) Suggest a way to ensure that the results are reliable. Explain your suggestion. [2]

Lingling held the cup of hot drink and almost scalded her fingers. The stall holder offered her a cup sleeve to put around her cup as shown below. She noticed that the inner side of the cup sleeve was corrugated. (a) Explain how the corrugated inner side of the cup sleeve will prevent Lauren from scalding her fingers. [2] When Lingling got home, she poured a cold drink into a double-walled cup to keep it cold for a long time. The double-walled cup has a layer of air between the two walls of the cup as shown below. [Figure: a double-walled cup with a lid and a layer of air between the two walls.] (b) Explain how the double walled cup helps to keep her cold drink cold for as long as possible. [2]