P5 Science SA2 2025 — Raffles Girls

The table below shows the characteristics of living things A, B, C and D. The tick (✓) in the boxes below show the presence of the characteristics of each living thing. Which one of the following correctly represents A, B, C and D?

Which of the following is true about the process of fertilisation in humans?

The table shows the physical characteristics of Mr Lee, Mrs Lee, and their children, John and Sally. [Table — Mr Lee: short nails, no dimples, straight hair. Mrs Lee: long nails, dimples, curly hair. John: short nails, dimples, curly hair. Sally: short nails, dimples, straight hair.] Based on the information, which of the following statement(s) is/are correct? A: Sally inherited her dimples from John. B: John inherited his curly hair from his mother. C: Sally and John inherited their short nail from Mr Lee.

The diagram shows the inherited trait A in Betty's family tree. [Family tree: Maternal grandparents — grandfather without trait A (white square), grandmother with trait A (filled circle). Paternal grandparents — grandfather with trait A (filled square), grandmother without trait A (white circle). Mother's siblings: one female with trait A, one male without trait A. Mother has trait A. Father's siblings: one female with trait A, one male without trait A. Father is without trait A. Betty's siblings: one female without trait A, one female with trait A (Betty), one female without trait A, two males with trait A.] Key: empty square = male without trait A, filled square = male with trait A, empty circle = female without trait A, filled circle = female with trait A. Which of the following statement(s) is/are true? A: All of Betty's male siblings have trait A. B: All of Betty's uncles did not inherit trait A. C: Betty's mother inherited trait A from her mother.

The diagram shows the cross-section of a flower. Which of the following shows the correct function of the part of the flower?

Sam collected seed A from a tree. In an enclosed laboratory, he conducted an experiment by dropping seed A from a height. He measured the distance, B, travelled by seed A. Which of the following graphs shows the relationship between B, the distance travelled by the seed, and the amount of wind present? [Graphs: (1) straight line increasing — B rises linearly with amount of wind. (2) straight line decreasing. (3) vertical line at a single point. (4) horizontal line, B constant.]

Samad took 4 similar flowers of the same plant and removed some parts of the flower. Which of these flowers will be able to develop into fruits? [Diagrams: Flower W — complete flower with petals, stamens (with anthers) and pistil intact. Flower X — only pistil (stigma, style, ovary) and sepals remain; petals and stamens removed. Flower Y — petals and stamens removed but only stigma+style present (no ovary visible). Flower Z — stamens removed; petals and pistil intact.]

Lionel observed the growth of a seed over ten days. [Table — Day 3: The seed coat broke. Day 5: Roots grew downwards. Day 7: Shoots emerged from the soil. Day 9: The first true leaves appeared. Day 10: Seed leaves shrivelled and dropped off.] On which day would the seed be able to make food?

Jessica set up an experiment as shown below. She poured equal amount of water into beaker A and B. She added a plant in beaker A and placed both beakers by the window for a week. Which graph correctly shows the change in the amount of water in both beakers? [Graphs: (1) both lines decrease but A decreases faster, B nearly flat. (2) both decrease but B decreases more / faster. (3) A decreases more slowly than B. (4) both stay flat.]

The chart shows how different systems work together to transport oxygen in the human body. [Flowchart: System E → (oxygen) → System F → (oxygen) → System G.] What are systems E, F and G?

The bar graph shows the amount of digested and undigested food leaving the different organs of the human digestive system. [Bar graph: organs H, I, J, K on x-axis vs amount of food (g). H: tall bar mostly undigested with small digested portion. I: short bar of undigested food only. J: tall bar mostly undigested with small digested portion. K: tall bar with about equal undigested and digested portions (most digested food).] Which part of the digestive system represents the stomach?

Which of the following statements about inhaled air and exhaled air is correct?

The diagram shows the human and fish circulatory system. The arrows represent the movement of blood in the blood vessels, O, P, Q, R, S, T and U. [Human Circulatory System: Lungs ←R— Heart, Lungs —O→ Heart, Heart —P→ Other parts of body, Heart ←Q— Other parts of body. Fish Circulatory System: Gills —S→ Other parts of body (via top arrow), Other parts of body —T→ Heart, Heart —U→ Gills.] Which of the following statements are correct? A: Blood vessels O and P transport blood containing more oxygen than Q and R. B: Blood vessels T and U transport blood containing more carbon dioxide than S. C: Blood passes through the heart twice in the human circulatory system but only once in the fish.

Which of the following correctly shows the movement of water in the plant transport system? [Diagrams of plants showing different arrow directions: (1) arrows go up from roots through stem and into leaves with small upward arrows in leaves. (2) arrows go down from leaves and into roots. (3) arrows in leaves point outward to the sides. (4) arrows show water moving down from leaves into stem into roots.]

Carrie split the bottom of the stem of a white flower into two equal parts. She placed one end of the stem in a container of water with red dye and the other end in a container of water with blue dye. After some time, Carrie observed that the flower changed colour. Which of the following statements is correct? A: The flower turned purple. B: The flower turned half red and half blue. C: The flower transported the dyed water separately.

Jialing placed a cup of ice on a table in the kitchen and measured its temperature over a period of time as shown. [Graph: Temperature (°C) vs Time (min). Starts at 0°C and remains flat at 0, then rises along a slope to point A, then plateaus from A to B at a constant higher temperature.] Which statement best describes the state of water at AB?

For water cycle in nature, which one of the following can possibly be formed when water vapour in the air loses heat? A: Mist; B: Rain; C: Steam; D: Clouds

The table below shows the state of four substances, K, L, M and N, at different temperatures. [Table — At 25°C: K solid, L solid, M solid, N solid. At 50°C: K liquid, L liquid, M liquid, N solid. At 75°C: K liquid, L gas, M liquid, N solid.] Which of the following statements are correct? A: K is a solid at 10°C. B: Substance L has the highest boiling point. C: Substance N has the lowest melting point. D: The melting point of substance M is between 25°C and 50°C.

Sue placed two identical bottles, filled with same amount of liquids, X and Y, near a window. She observed there was less liquid Y left in the bottle than liquid X after two days. What can Sue conclude from her observations? A: Liquid Y evaporates faster than liquid X. B: Both liquids need sunlight for evaporation. C: Liquid Y needs more heat than liquid X to evaporate.

Janet looked through a glass container and saw a candle in it. Which statement explains why she can also see the glass container?

May prepared three cut-outs, P, Q and R as shown in the diagram below. [Diagrams: P is a 5 cm × 5 cm square; Q is a triangle with base 5 cm and height 5 cm; R is a 5 cm × 5 cm square.] She shone a torch on the cut-outs and observed the shadow cast on the screen. Based on the shadow formed, which of the following statement(s) is/are definitely correct? A: Q allows no light to pass through. B: P allows most light to pass through. C: R allows some light to pass through.

The diagram shows how a light source and a light sensor could be used to determine the transparency of cubes A, B, C and D. They were placed on a moving belt which moved at a constant speed. The four cubes were made of different materials. The amount of light detected by the light sensor was plotted on a graph shown below. [Graph: Amount of light vs Time(s). Levels: at A region the amount of light dips moderately, at B region it dips deeply, at C region it drops to zero, at D region the amount is highest with only a tiny dip.] Based on the graph above, which of the materials is most suitable to make into a display cabinet for ceramic art work?

George could not remove the metal lid from a glass jar in an air-conditioned room. He poured hot water on the metal lid. Based on the information above, which one of the following statements explains why the lid was easily removed?

Nicole filled two similar beakers X and Y with 500 ml of water each at 80°C. She then surrounded the beaker Y with six other similar beakers, all filled with 500 ml of water at 80°C as shown in the diagram. Nicole measured the temperature of the water in both beakers X and Y every 5 minutes interval for 30 minutes. She plotted the results in the graph below. [Graph: Temperature vs Time. Both lines start at 80°C; X drops faster reaching a lower value, Y drops slower and remains higher.] Based on the data recorded in the graph above, what can Nicole conclude about the experiment?

Two steel balls, R and S, of different masses were put into a beaker of water and heated until the water boiled. Based on the experiment above, which of the following statement(s) about the steel balls is/are correct when the water was boiled? A: R would be hotter than S. B: R would contain more heat than S. C: R and S would have the same temperature. D: R and S would contain the same amount of heat.

Study the electric circuits below. [Diagrams: Circuit A — bulb connected to a battery with both terminals correctly connected by wire forming a closed loop. Circuit B — bulb connected with wire that bypasses one terminal (open circuit). Circuit C — bulb with both wires connected to the same terminal of the battery (short, no closed loop). Circuit D — bulb connected with only one wire to battery, loop not closed.] In which of the circuit(s) will the bulb light up?

Susan wanted to find out if the arrangement of bulbs in a circuit affects the brightness of the bulbs. She set up four circuits using the components as shown below. [Diagrams: Circuit A — one bulb in a simple closed loop with battery. Circuit B — two bulbs connected in series. Circuit C — two bulbs in series with the same battery. Circuit D — two bulbs in parallel with the battery.] Which two circuits should she use to carry out her experiment?

The diagram shows the front view of a circuit card made by clipping some paper clips to a piece of cardboard. Some of the paper clips were connected to copper wires at the back. Different points of the circuit card were connected to a circuit tester. A diagram of a circuit tester is shown below. [Diagram of a simple battery-bulb circuit tester with two test leads.] The results were recorded in the table below. [Table — A and B: ✓ (bulb lit). B and G: ✓ (bulb lit). C and G: not lit. A and G: ✓ (bulb lit). C and H: not lit. F and E: ✓ (bulb lit).] Which of the following shows the correct wire connection at the back of the circuit card? [Options (1)-(4) show different octagonal diagrams with internal wires connecting various points.]

An iron rod can be magnetised using the 'stroke' method as shown in Diagram 1. Diagram 2 shows the magnetic poles of the iron rod after it was magnetised. [Diagram 1: a single bar magnet with S on top and N on bottom is stroked along an iron rod in one direction. Diagram 2: the iron rod becomes magnetised with poles N (left) and S (right).] Alex stroked an iron rod using two magnets as shown in Diagram 3. [Diagram 3: two bar magnets held side by side (left magnet has S on top, N on bottom; right magnet has N on top, S on bottom) stroking from the centre outwards along the iron rod in opposite directions.] What would happen to the iron rod after Alex stroked it 30 times?

A compass has a magnetic needle that rotates freely. Five bar magnets were positioned side by side. The compass was placed near the end of X and the needle of the compass moved as shown. [Diagram: five bar magnets arranged in a U/staircase pattern from X to Y. Compass placed near X shows north pole pointing downward (towards X).] Which of the following shows the correct position of the needle when the compass was placed at Y? [Options show compass needle pointing: (1) up, (2) down, (3) left, (4) right.]

The diagram below shows the plant reproductive system and the human reproductive system. (a) In the diagram above, label the part in the plant reproductive system that has a similar function to part A with the letter 'X'. [1] (b) The diagram below shows a female human reproductive system. Label the part where the fertilised egg develops into a foetus with the letter 'T'. [1] [Diagram: Female reproductive system showing uterus, fallopian tubes, ovaries, cervix.] Parts R and S were clipped such that there is a complete blockage at R and S. [Diagram: Female reproductive system with clips on R and S (both fallopian tubes).] (c) Can sexual reproduction still happen naturally? Give a reason for your answer. [2]

The diagram below shows two fruits, P and Q, from different plants. (a) State the method of seed dispersal of fruit P. [1] (b) Describe how the seeds of fruit Q are dispersed. [1] (c) Explain why seed dispersal is important for plants. [2]

The leaves of the plant contain tiny openings which control water loss. Emma wanted to compare the number of tiny openings on the upper and lower surfaces of the leaves. She used four similar plants and placed them in identical beakers containing equal amount of water with a layer of oil on the top. [Diagram: Four plant set-ups A, B, C, D each placed in beakers of water with oil on top.] Emma coated different surfaces of the leaves with oil. [Table — Set-ups: A: None of the leaves was coated with oil. B: Upper surface of the leaves was coated with oil. C: Lower surface of the leaves was coated with oil. D: Both surfaces of the leaves were coated with oil.] She measured the mass of each set-up and left them by the window. After two days, she recorded the decrease in mass of the set-ups. [Table — A: 3 g; B: 2 g; C: 1 g; D: 0 g.] Emma concluded that there were more tiny openings found on the lower surface of the leaves than the upper surface. (a) Besides controlling water loss, state another function of the tiny opening on the leaves. [1] (b) What is the purpose of the layer of oil added to the water in each set-up? [1] (c) Explain the difference in mass between set-up B and C. [2]

The diagram shows organs of the human digestive system. (a) State the function of organ D in digestion. [1] The process of food mashing is shown in the diagram. [Diagram: hands using a masher on sweet potato in a bowl.] (b) Organ E is not fully developed in infants. Explain why there is a need to mash the sweet potato before feeding it to an infant. [2]

Andrew measured his heart and breathing rate every ten minutes while jogging around a park. [Graphs: Heartbeat rate per minute starts at 70 and remains nearly constant over 30 minutes. Breathing rate per minute starts at 20 and increases gradually over 30 minutes.] (a) Based on the graphs, state the relationship between Andrew's heartbeat rate and breathing rate. [1] (b) Explain the change in Andrew's heart rate as he was jogging. [2]

The air sac in the lungs is surrounded by blood vessels and is where gaseous exchange takes place. Doctors compared the air sac of a healthy individual with that of an individual who is infected with influenza A, also known as the flu. The diagrams show their findings. [Diagrams: Healthy individual — air sac surrounded by blood vessels, hollow inside. Individual infected with Influenza A — air sac filled with liquid, surrounded by blood vessels.] [Table — Surface area of air sac for gaseous exchange (unit): Healthy individual = 3; Individual infected with Influenza A = 1.8.] (a) Describe the exchange of gases that takes place in the lungs. [1] (b) Based on the table, explain why the individual infected with influenza A has difficulties breathing compared to the healthy individual. [2]

Farmer Tim removed the food-carrying tubes around part F of the stem of Plant G as shown in the diagram. (a) After two weeks, Farmer Tim observed that Plant G started to bear fruits, and certain portion of part F had become swollen. Put a tick (✓) in the correct box which shows his observation of part F after two weeks. [1] [Three boxed options: (left box) stem swollen above the removed ring; (middle box) stem swollen below the removed ring; (right box) stem with no swelling.] Farmer Tim also observed that there was a difference in the fruit of Plant G before and after the food-carrying tubes were removed. [Diagram comparing fruits — small fruit before, larger fruit after.] (b) Explain the differences in the fruit after the food-carrying tubes were removed. [2]

Angeline set up an experiment. She placed an empty cup in a container of water. Then she placed a dish covering the container. Observation made after ten minutes: water droplets on underside of dish and water collected in the cup. (a) Based on the observation made, did Angeline put hot or cold water in the container? Explain your answer. [2] (b) Angeline put some ice cubes on the dish. Explain how this would help her to collect more water in the cup. [1] (c) Using the same apparatus, suggest another way for Angeline to collect more water in the cup. [1] Based on what Angeline learnt from the experiment set-up, she designed the following device to make the air in her room drier. [Diagram of dehumidifier: inlet for moist air at top, long cooling coil inside, outlet for drier air; water collection at bottom.] (d) Based on the above diagram, explain how the device can make the air in her room drier. [1]

Peter set up an experiment as shown below. All the rods were of the same length but made of different types of materials. He placed the same amount of wax on the tip. He recorded the time taken for the wax on the rods to melt completely. He plotted his results in the graph below. [Bar graph: time taken for wax to melt (min) — W: tallest bar (longest time); X: shortest bar; Y: medium bar; Z: second tallest bar.] (a) Which material is the most suitable for making the handle of a cooking pan? Explain your answer. [2] Peter carried out another experiment using material X attached on top of a piece of material W. [Diagram: material X with hole cut-outs placed on top of material W; cross-section showing material X (thin layer with holes) attached to material W (vertical lines pattern below).] He placed material X attached on top of a piece of W over a flame as shown in the diagram below. [Diagram: material X with hole cut-outs on the top layer and material W on the bottom layer placed over a flame from a Bunsen burner.] The diagram below shows the observation made on W after turning on the flame for a short period of time. [Diagram: area of material W below X is not burnt; areas of material W not covered by X (where the holes are) are burnt.] (b) Explain the observation made above. [2]

Ali made a toy consisting of 3 similar bulbs, A, B and C and a switch. The toy works as described below. • The switch controls only bulbs A and B. • When bulb A is fused, only bulb C will be lit. • When bulb C is fused, both bulbs A and B will be lit. (a) The diagram shows part of Ali's circuit. Complete the circuit diagram below by using a switch and wires so that they will function as described above. [3] (b) Describe the brightness of bulb A in comparison with bulb C. [1]

Luke created a fishing game as shown. The objective of the game is to catch toy fish, W, X, Y or Z, using the bars. The bars were made of metals. He recorded in the table below the interactions when the bars on the fishing rods were brought nearer to the fish. [Table — Fish W: Bar S caught it; Bar T no interaction. Fish X: Bar S caught it; Bar T no interaction. Fish Y: Bar S moved away; Bar T caught it. Fish Z: no interaction with either.] (a) Based on the information above. Put a tick (✓) in the correct box for each statement. [2] [Statements with True/False boxes: Fish Z is a magnetic object. Fish X is a magnetic object. Fish W is a non-magnetic object. The bar on fishing rod T is made of copper.] (b) Luke concluded that fish Y is a magnet. Do you agree with him? Explain your answer. [1]