P5 Science SA2 2025 — Nanyang

The diagrams below show parts of the human reproductive system. In which of the parts, A, B, C or D, does a fertilised egg develop into a baby?

Study the information in the table below. Which of the following correctly identifies E, F, G and H?

Jenny has a plant in her garden that produces brightly-coloured flowers. She removed the petals of one of the flowers. A section of this flower is shown below. She observed that the flower without petals took a longer time to be developed into a fruit as compared to the flower with petals. Which one of the following statements about the flower without petals best explains Jenny's observation?

Refer to the diagrams and information below to answer Questions 4 and 5. Cayden removed the food carrying tubes from a tree as shown in the diagram below. After two weeks, she noticed that only fruit P became bigger. Which of the following explains why only fruit P became bigger?

Which of the following are possible observations of the whole plant after a few weeks?

Which of the following correctly shows the function of the nose and the lungs? [Table comparing Function of Nose and Function of Lungs across four options]

Which of the following correctly shows the comparison of oxygen and carbon dioxide in the air that we breathe?

Ahmad drew the diagram below to represent blood flow in some parts of the body. Which of the arrows are wrongly drawn?

Which of the following is the correct function of the human circulatory system?

The diagram below shows the processes taking place in organs M and P, which are parts of the human digestive system. Which of the following correctly identifies organs M and P?

Jenny set up two identical beakers, Q and R, with the same amount of digestive juice and the same mass of meat in each beaker as shown in the diagram below. Four hours later, Jenny weighed the mass of the remaining meat in each beaker. While the mass of meat in both beakers decreased, she observed that the total mass of meat in beaker Q is less than the mass of meat in beaker R. Based on her observations, she concluded her investigation by making the following statements: A No digestion took place in beaker R. B More digestion took place in beaker Q. C Smaller pieces of food help to speed up digestion. D The mass of food in each beaker at the start affected the rate of digestion. Which of the statements are correct?

Which group of living things has a four-stage life cycle?

The diagram below shows the life cycle of animal X. The graph below shows the number of weeks animal X remains in each stage of its life cycle. [Bar graph: egg ≈ 3 weeks, young ≈ 5 weeks, adult ≈ 9 weeks] Based on the graph, which statement about the life cycle of animal X is correct?

Which of the following correctly shows the life cycle of a plant?

The table below shows the freezing and boiling point of three substances, X, Y and Z. Based on the table above, which of the following statements is correct?

In the diagram below, A, B, C and D represent the different processes that result in a change in state of water. Which of the following processes correctly represent A, B, C and D?

Ali poured an equal amount of water at different temperatures into 2 identical cups, A and B. He covered the cups with identical lids and left them in a room at 29°C. The diagrams below show what Ali observed after 10 minutes. Which of the following shows the most likely temperature of water in each cup? [Table of four options for temperatures in cups A and B in °C]

Study the diagram below. In what ways are the cloud in the sky and the mist formed around the spout of the kettle of boiling water similar? A Both are in liquid state. B Both are of the same temperature. C Both are formed by water gaining heat from the surrounding air. D Both are formed by water vapour losing heat to the surrounding air.

A large amount of fertilizer from a vegetable farm and animal waste from an animal farm flows into a nearby river at point X. A factory nearby would also dump their toxic waste into the nearby river. The arrow shows the direction in which the river flows. It was observed that the presence of fertilizer and animal waste turned the water cloudy. Which of the following graphs best represents the effect of fertilizer, animal waste and toxic waste on the amount of fishes in the river? [Graphs: (1) low then sharp rise to a high plateau; (2) low rise to a bump then back down; (3) high, drop sharply at X, then quick return to high; (4) high, drop sharply at X, then slow gradual return to high]

Which of the following activities can cause water pollution? A Using rainwater to wash the toilet. B Watering plants with water from washing rice. C Littering and dumping of waste into canals and rivers. D Spraying insecticide over the water in drains and ponds.

Lucian set up four circuits using identical batteries and bulbs as shown. All the circuit components are in working condition. In which circuit would both bulbs light up?

Connie set up the electric circuit as shown below. All the electrical components are working. She observed that only bulb U lit up. Which of the following is correct? [Table comparing Material V and Material W across four options]

Refer to the diagram below to answer Questions 23 and 24. The diagram below shows a wire loop game which requires players to guide a loop along a wire. When the loop touches the metal maze, the bulb will light up. Which statement(s) is/are correct? A When the loop touches the metal maze, a closed circuit is formed. B The wire, loop and handle are made of electrical conductors.

Which statement(s) shows unsafe ways to play the wire loop game? P Use wires that are not insulated. Q Hold only the handle to play the game. R Touch the metal maze with wet hands.

Which of the following practices will help to conserve electricity?

Study the flowchart below. [Flowchart: Matter → 'Does it have a definite shape?' → Yes: P, No: 'Does it have a definite volume?' → Yes: Q, No: R] Which of the following best represents Q?

Jaya pumped more air into a basketball. The diagram below shows her observations of how the size and shape of the basketball did not change. Which of the following best explains her observations?

The device below measures the oxygen levels and pulse rate. In this device, light from the light source reflects off a person's finger into a light sensor. The light ray is shown in the diagram below. Based on the diagram, which statement is not correct?

Nora stood under a lamp as shown below. She walked in a straight line from position X to position Y, and then to position Z. Which graph shows how the length of her shadow changed during this time? [Graphs: (1) rises from X to Y then falls to Z; (2) high at X, decreases to Z; (3) high at X, drops to low at Y, then rises again to Z; (4) flat horizontal line]

The diagram below shows Kumar holding a metal plate in one hand and a wooden plate in the other. He noticed that the metal plate felt cold but not the wooden plate. If both plates were in the same room for the same duration, why did the metal plate feel cold while the wooden plate did not?

The diagram shows the fruits and seeds of different plants. (a) Based only on the observable characteristics of the fruits and seeds above, which one is most likely dispersed by water? Explain your answer. [2] (b) What is the disadvantage for the dispersal method of fruit Y? [1] (c) Study the diagram below. [Diagram: Stage 1 seed in soil; Stage 2 germinating seed with root and seed leaf above ground; Stage 3 young plant with true leaves and a much smaller seed leaf] State all the conditions needed for the seed to germinate from stage 1 to stage 2. [1] (d) The seed leaf in stage 3 is observed to be much smaller than in stage 2. Give a reason for the observation. [1]

Herman went for a jog in the park. He measured his heart rate throughout the jog. The graph below shows his heart rate over a period of time. [Graph: Heart rate (bpm) vs Time (min). Point A at 0 min ≈ 60 bpm; Point B at 10 min ≈ 60 bpm; Point C at 30 min ≈ 100 bpm; Point D at 40 min ≈ 100 bpm; Point E at 50 min ≈ 60 bpm] (a) What is Herman's heart rate when he is at rest? ____ beats per min. [1] (b) Identify the point at which Herman (i) started running: Point ____ (ii) stopped running: Point ____ [1] (c) Describe and explain the change in Herman's heart rate when he stopped running. [2]

The table below shows the amount of undigested food in the different parts of the digestive system. [Bar graph: x-axis shows Mouth, Gullet, Stomach, Small Intestine, Large Intestine. Black bar = amount entering; hatched bar = amount leaving. Mouth entering ≈ 10, leaving not yet drawn (ai). Gullet ≈ 7.5 entering, 7.5 leaving. Stomach ≈ 7.5 entering, ≈ 6 leaving. Small intestine ≈ 5.5 entering, ≈ 3 leaving. Large intestine ≈ 3 entering, leaving not yet drawn (aii)] (a) Using the space within the dotted lines of the diagram above, draw two bars to complete the graph which best represent the following: [1] (i) Amount of undigested food leaving the mouth (ii) Amount of undigested food leaving the large intestine (b) State two functions of the small intestine. [2] (i) ____ (ii) ____ (c) Why does the amount of undigested food entering and leaving the gullet remain the same? [1]

Animal X lives on land and only its young are found on the leaves of plants. The adult of animal X feeds on other insects to survive. When animal X is found on the plants in a farm, farmers will have more damaged plants. In 2025, farmers sprayed substance Q on the leaves of plants to reduce the amount of damaged plants. When substance Q is eaten, only the young of animal X is affected. (a) State the stage of the life cycle affected by substance Q. Give a reason for your answer. [1] (b) Complete the line graph below to show how the number of animal X will change over time after the farmers sprayed substance Q on the leaves of plants in 2025. [Graph: x-axis = Time (year) showing 2024, 2025, 2026; y-axis = Number of adult X; a horizontal line is shown from 2024 to 2025 at a certain level] [1] (c) State one similarity and one difference between the life cycle of animal X and the life cycle of a grasshopper. [2] (i) Similarity: ____ (ii) Difference: ____

Alima wanted to find out if the amount of water affects the height of a plant after two weeks. She prepared four pots of seeds, as shown in the table below. (a) Which two pots of seeds should Alima use for the experiment to be a fair test? [1] (b) Which of the following apparatus should Alima use to accurately measure the height of the plant? Put a tick (✓) in the correct box. [Diagram: beaker, ruler, weighing balance, 1cm unit cubes] [1] Alima carried out her experiment using the appropriate pots of plants. She watered one pot with 50ml of water daily and the other pot with 100 ml of water daily. Her results are shown below. [Bar graph: Height of plant (cm) over Week 1, Week 2, Week 3. Black bars = 50 ml; hatched bars = 100 ml. 100 ml bars are taller in each week.] (c) State what Alima can conclude from her results. [1]

Shanti has two containers, X and Y, as shown below. She filled the containers with 500 ml of water each. She left the containers on a table in the same room for two days and then measured the amount of water left in the containers after two days. (a) Why did Shanti use the same amount of water at the start of the experiment? [1] (b) Which container would have more water left in it after two days? Explain your answer. [2] (c) State another way in which the rate of evaporation of the water can be increased. [1]

John put together the set-up below. The container has a capacity of 300 cm³. (a)(i) What is the volume of air in the container? ____ cm³ [1] Using the pump, 50 cm³ of water was added into the container. (a)(ii) What is the final volume of air in the container? Explain your answer. [2] To release the water in the container, a small hole was made at the bottom of the container and water started dripping out slowly. (b) Without changing the hole or adding another hole, what can John do to increase the rate of water dripping out of the container? [1]

Liam conducted an experiment using two beakers, F and G. The table below shows the conditions in both beakers. Liam wanted to cook an egg by leaving it in the beaker of hot water. (a) In which beaker would the egg cook faster? Give a reason for your answer. [2] Liam conducted another experiment using 2 beakers made of identical materials, J and K. The beakers are completely filled with water. He placed a lid made of different materials on beakers J and K. After 3 minutes, he measured the temperature of water in both beakers and recorded it in the table below. [Table: Beaker J — Start temp 80°C, Volume 200 ml, End temp 45°C; Beaker K — Start temp 80°C, Volume 200 ml, End temp 20°C] (b) Suggest a possible material for the lid covering beaker K. Explain your answer. [2]

Mei Mei made an electromagnet as shown in the diagram below. (a) State one way Mei Mei can increase the strength of the electromagnet without using other materials. [1] The diagram below shows a car park barrier which uses an electromagnet to operate. When there is no car in front of the barrier, the switch is open and the barrier is in the position shown in the diagram below. [Diagram: A horizontal barrier with one end attached to part K which is connected to a steel weight on the left side; an iron rod (electromagnet) is positioned below the steel weight, connected to a battery via a switch] (b) Based on the diagram above, explain clearly how the electromagnet helps to lift the barrier when the car approaches. [2]

Harold bought a toy microwave as shown in diagram 1. The electric circuit of the microwave contained a motor to spin the plate, bulb P and bulb Q as shown in diagram 2. Bulbs P and Q are identical bulbs. All the circuit components are in working condition. [Diagram 1: A toy microwave with a lamp inside, a light-up display on the front, and a spinning plate. Diagram 2: A circuit with a battery, bulb P in series with the motor in one branch and bulb Q in parallel — specifically, P is in series in the main loop while the motor is in a branch parallel to Q] When the motor for the spinning plate stopped working, the lamp no longer lit up but the light-up display could still work. (a) Identify the bulb used for the lamp and light-up display respectively. [1] Lamp: Bulb ____ Light-up display: Bulb ____ (b) Give a reason why the bulb for the light-up display could still work when the motor stopped working. [1] Harold replaced the motor with bulb R. Bulb R is identical to bulbs P and Q, and in working condition. (c) Describe and compare the brightness of bulbs P, Q and R. [1] (d) Harold wants to rearrange the circuit such that all the bulbs have the same brightness. Draw the circuit diagram of the rearranged circuit by including the following: 3 battery, 3 bulbs, wires [2]