P4 Science SA2 2025 — Nanyang

Which one of the following is a non-living thing?

Study the chart below. Which group, A, B, C or D, does the animal shown below belong to? [Figure: cockroach with six legs]

The diagram below shows a plant. The roots help the plant to ____ .

Which human system is shown in the diagram below?

P, Q and R are stages in the life cycle of a plant. Which of the following shows the correct life cycle of the plant? [Figure: four cyclic arrangements of P, Q and R]

In which one of the following will the two magnets push each other away?

The diagram shows a magnifying glass. Glass is used to make the lens of the magnifying glass because glass ____ .

Look at the picture below. Which one of the following explains why Mrs Tay can see the vase on the table? [Figure: four diagrams labelled (1)–(4) showing different directions of arrows between lamp, vase and Mrs Tay; arrow legend shows 'direction of light']

Raju pours boiling water into a metal cup as shown below. He is not able to hold the metal cup with boiling water with his bare hands as it is too hot to touch. This is because metal is a ____ .

Matter is anything that has mass and occupies space. Which one of the following is not matter?

Which of the following are characteristics of all living things? A grow and reproduce; B make their own food; C able to move on their own; D respond to changes around them

Study the three animals, P, Q and R and the classification chart below. Which animals do Y and Z represent?

Study the flowchart below. Which of the following correctly represent L, M and N?

If stage W represents the egg, what does stage X represent?

Which of the following animals does not have a life cycle that matches the life cycle shown above?

The diagram below shows a green plant. Which statement(s) is/are definitely correct? A This plant can make food. B This plant has a weak stem. C This plant is a non-flowering plant.

Devi wanted to find out if the presence of roots affects the absorption of water in plants. She prepared two set-ups, G and H, as shown below. Which of the following variables should Devi keep constant? A Number of roots on each plant; B Number of leaves on each plant; C Amount of water in each container at the end of the experiment; D Amount of water in each container at the start of the experiment

The diagram below shows the human respiratory system. What are parts J and K?

W and X are similar containers containing the same volume of digestive juices. The total mass of carrots placed in each container is the same. The carrots had been cut into cubes of different sizes. Why did the carrots in container W take a shorter time to be fully digested as compared to the carrots in X?

The table shows the processes taking place in organs R, S, T and U. A tick (✓) indicates that the process takes place in that organ. Which of the following correctly shows the parts labelled R, S, T and U? [Figure: four labelled body diagrams of digestive organs]

Kai Leng has to select the most suitable materials for making a raincoat and the base of a frying pan. Based on classification chart above, which of the following shows the best materials, D, E, F, G or H to make each item?

Sally lowered a bar magnet into a container of steel pins as shown in the diagram below. Then, she counted the number of steel pins that were attracted to each of the parts marked W, X and Y. Which of the following correctly shows the most likely number of steel pins attracted to the bar magnet?

Lucas put an equal number of paper clips into two containers, X and Y. He pushed two identical magnets into the two containers as shown in the diagram below. When he lifted both the magnets, he observed that the paper clips in container X were attracted to the magnet whereas the paper clips in container Y were not attracted to the magnet as shown in the diagram below. [Figure: container X — clips clinging to the magnet; container Y — clips remain on the bottom.] What could the materials of the paper clips in containers X and Y most likely be made of?

Three objects, X, Y and Z, of the same shape and size are placed at different positions from a torch. X, Y and Z are made from different materials. The shadows formed on the screen for the different arrangements are shown below. Which of the following is correct?

Mrs Tan was walking from position A to position C, as shown in the diagram below. She took 1 minute to walk to B and stopped for 2 minutes. She continued walking and reached C after 1 minute. Which graph shows the change in the length of Mrs Tan's shadow during the 4 minutes? [Figure: four length-of-shadow versus time graphs]

Ming Teck took out an ice cube from the freezer and placed it inside a metal container as shown in the diagram below. Ten minutes later, he observed that the ice cube had melted and the metal container felt cold. Which statement(s) below correctly explain(s) Ming Teck's observations? A The ice cube lost heat to the surrounding air. B The metal container lost heat to the ice cube. C The metal container gained heat from the ice cube.

Which one of the following statements is true?

Ravi wanted to find out if the amount of water in the beaker at the start of the experiment affects the time taken for the water to boil. To ensure a fair test, which set-ups should be used for his investigation?

Substances S and T are placed in two upright containers. When the containers are tilted to its sides, the observation is shown in the diagram below. Which of the following statements are definitely correct? A Substance S is air. B Substance T could be ice. C Substance S and T have definite volume. D Substance S and T have no definite shapes.

Charissa stuck a piece of tissue paper to an empty glass and lowered it into a container of water until the glass touched the bottom of the container. The tissue paper remained dry as shown in the diagram below. Which one of the following statements correctly explains why the tissue paper remains dry?

The diagram below shows the human digestive system. Identify the part (W, X, Y and Z) where (a) food is first broken down: ____ [1] (b) digestion ends: ____ [1]

The diagram below shows the stages in the life cycle of a plant. Choose the correct words from the box to answer the question below. Box: young plant, egg, seed, adult plant. Name stages J and K in the life cycle of the plant. J: ____ K: ____

Look at the pictures. Tick (✓) the sources of light.

Yu Ying placed a rubber rod and a metal rod into a tank of boiling water as shown below. Equal amounts of wax were put on both rods. What would she observe and why? The wax on the rubber rod melted ____ than the wax on the metal rod, as rubber is a ____ conductor of heat than metal.

Nur placed magnet F, magnet G and a wooden block on the table as shown in the diagram below. (a) Why did magnet F move towards magnet G? Magnet G was ____ magnet F. [1] (b) The wooden block did not move towards magnet G. This is because wood is a ____ material. [1]

Study the flowchart below. (a) Based on the flow chart above, state all the characteristics of living thing S. [1] (b) Based on the flow chart above, state one difference between the characteristics of living things Q and R. [1] (Continue from ____) [Figure of tree L bearing fruits, with M = a fern-like plant growing on the trunk and N = small fungi/mushrooms growing on the branch.] Ben observed that tree L has no flowers. He classified it as a non-flowering plant. (c) Ben's teacher said that his answer was wrong. Give a reason why. [1] Ben also noticed that both M and N were growing on tree L. He found spores on them. However, Ben stated that M and N are different in the way they get their food. (d) State one difference in how M and N get their food. [1]

Bacteria S is harmful and can cause humans to fall ill when a lot of it is present. Bruce conducted an experiment to find out how quickly bacteria S can reproduce when it is kept at different temperatures. He recorded his observations in the table below. (a) Predict the amount of bacteria S at 54 °C. ____ units [1] (b) State the characteristic of living things that explains why the amount of bacteria S changed after 5 hours. [1] (Continue from ____) Bacteria S can be found on raw food. Bruce conducted a second experiment to find out if bacteria S can be killed at high temperatures. He heated the same amount of bacteria at different temperatures for 20 minutes. The results are shown in the graph below. [Figure: bar chart — at 80 °C a moderate amount of bacteria remains after 20 minutes, at 90 °C less remains, at 100 °C only a small amount remains. White bars = start, black bars = after 20 min.] He cooked a raw fish at a temperature of 100 °C for 20 minutes. The cooked fish was then left on the table at 30 °C for 5 hours. (c) Based on the two experiments Bruce had conducted, explain why the cooked fish is no longer safe for Bruce to eat after 5 hours at 30 °C. [2]

The graph below shows the amount of undigested food leaving the different parts of the digestive system. (a) Other than the mouth and gullet, identify the 3 other parts of the digestive system. [1] (b) State the 2 functions of the small intestine. (i) ____ (ii) ____ [2] (c) Explain why the amount of undigested food that leaves the mouth is the same as the amount of undigested food that leaves the gullet. [1]

Ravi hung 4 magnets, D, E, F and G, at the same height above a tray of steel paper clips as shown in the diagram below. Then, he recorded the number of steel paper clips attracted by each magnet in the table below. Magnet D=5, E=2, F=9, G=7. (a) Based only on the information above, put a tick (✓) in the box(es) where the statement is/are correct. [1] Statements: (i) Magnetism cannot interact from a distance. (ii) The magnet's magnetic strength does not depend on its size. (iii) Magnet G has a greater magnetic strength than magnet D. (iv) As the size of the magnet increases, its magnetic strength decreases. (Continue from ____) Ravi wanted to use the electrical method to magnetise an iron nail. He turned the iron nail into an electromagnet as shown in the set-up below. The iron nail was able to attract some steel paper clips. [Figure: an iron nail wrapped with insulated wire connected to a battery; some steel paper clips cling to the nail.] (b) Suggest two changes Ravi could make to the set-up above to enable the iron bar to attract more steel paper clips. (i) ____ (ii) ____ [2] When Ravi placed some other metal pins under his magnetised iron bar, he noticed that the metal pins were not attracted to his magnetised iron bar. (c) Suggest one reason why the metal pins were not attracted to his magnetised iron bar. [1]

(a) Describe how shadows are formed. [1] Kenny made object Y using a metal ball and wooden stick. Using a marker, he drew a smiley face on object Y as shown below. In a dark room, he placed object Y between a torch and a screen as shown below. [Figure: torch on left, object Y in middle, screen on right.] (b) In the box below, draw the shadow formed on the screen when Kenny turned the torch on. [2] (Continue from ____) (c) Using the same set-up as above, state one way Kenny can cast a bigger shadow on the screen. [1] In another experiment, Kenny arranged the torch, a wooden cube and a rubber ball in a straight line as shown below. [Figure: lit torch on left, then a 5 cm wooden cube, then a 5 cm rubber ball, then the screen — all in a straight line.] (d) In the table below, place a tick (✓) in the box with the correct shadow that will be cast on the screen when the torch was switched on. [Figure: four possible shadow shapes — (i) circle on top of a stick, (ii) circle outline with a smaller square inside, on a stick, (iii) solid square on a stick, (iv) solid square with a circle outline inside.] [1]

(a) What are good conductors of heat? [1] Mdm Tan placed three identical rods of different materials, J, K and L, into a container of ice as shown in the diagram below. All three rods had the same temperature of 26 °C when they were placed into the container of ice. Five minutes later, Mdm Tan took the three rods out of the beaker and recorded their temperatures in the table below. Materials: J=5 °C, K=13 °C, L=9 °C. (b) Based on the results of the table above, which material J, K or L, is suitable for making the cup and its lid if Mdm Tan want her cold drinks to be kept cold for the longest period of time? Explain your answer using information from the table above. [2] [Figure: a cup with a lid.] (Continue from Question 41) Mdm Tan filled 2 identical kettles, Y and Z, with the same amount of water at 99 °C. Then, she placed the two kettles on steel plates as shown in the diagram below. [Figure: kettle Y on a steel plate with no gaps; kettle Z on a steel plate with 4 cm gaps.] She recorded the time taken for the water in the kettles to cool down to 50 °C, in the table below. Y = 20 minutes; Z = 40 minutes. (c) Explain why the water in kettle Z took a longer time to cool down to 50 °C. [2]

(a) State one difference between the property of solids and liquids. [1] Zhen Zhen placed 2 irregular objects with different volumes, into 2 similar containers. She then filled the two containers with water to the same height as shown in the diagram below. Zhen Zhen's teacher handed her two measuring cylinders as shown in the diagram below. [Figure: two empty measuring cylinders labelled 10, 20, 30, 40, 50.] (b) Using the measuring cylinders, explain how Zhen Zhen can conclude which object has a smaller volume. [2] (Continue from Question 42) (c) Using the same method as above, Zhen Zhen tried to measure the volume of object X. Explain why she could not measure the volume of object X. [Figure: object X is a small ball floating on top of the water in a container.] [1]