Question 1

The following expression represents photosynthesis.

A + water --B/sunlight--> sugar + C

Which of the following shows the correct representation of A, B and C?

Accepted Answer

B. A: carbon dioxide, B: chlorophyll, C: oxygen. Photosynthesis uses carbon dioxide + water, in the presence of chlorophyll and sunlight, to produce sugar (glucose) and oxygen. So A = carbon dioxide, B = chlorophyll, C = oxygen.

Question 2

Study the food web below carefully.

Which animal obtains the most amount of energy from the food it eats?

Accepted Answer

C. grasshopper. Energy decreases along a food chain as it passes from one organism to the next. The grasshopper is closest to the producer (plant) — it is the first-order consumer — so it obtains the most energy from its food.

Question 3

The flowchart shows some parts of the human body system(s). A and B are substances found in the blood taken from the small intestine.

What do A, B and the above system(s) represent?

Accepted Answer

A. Substance A: digested food, Substance B: undigested food, System(s): digestive and circulatory systems. Digested food is absorbed from the small intestine into the blood (substance A) and carried to all parts of the body, while undigested food (substance B) passes to the large intestine and out of the body. The flowchart involves both the digestive and circulatory systems.

Question 4

Jie Min found a spider crab with algae attached to its back. His teacher told him that this was a case of mutualism where both species benefit from each other. Which of the following statements are true?

A: The spider crab would feed on the algae.
B: The spider crab gives the algae a place to live in.
C: The algae provide camouflage for the spider crab.
D: The algae absorb nutrients from the spider crab until it dies.

Accepted Answer

C. B and C. In mutualism both benefit. The spider crab gives the algae a place to live (B) and the algae provide camouflage for the crab (C). Statement A (crab feeds on algae) and D (algae harm the crab) describe harm/one-sided relationships, not mutualism.

Question 5

Ali carried out an experiment to study the environment that worms preferred. Ten worms were put in a box which is divided into two separate parts, Part X and Part Y, as shown in the diagram below. The live worms could move from Part X to Part Y through a small opening at A. After some time, it was observed that all the worms have moved into part X.

Which of the following set-ups would you use to find out how worms respond to light?

Accepted Answer

A. Both halves have black cloth on one side and clear glass with light on the other; both halves have moist cotton wool.. To test response to light, only light should differ (one side dark with black cloth, the other bright with clear glass and light) while all other conditions, especially moisture, must be kept the same. Set-up (1) has moist cotton wool in both halves and differs only in light, so it is a fair test for light.

Question 6

A group of students counted the organisms found in a pond. The results are shown below.

Which of the following statements about the plants and animals are correct?

A: There are 12 populations of plants.
B: There is only one pond community.
C: There are at least three populations of animals.
D: All the animals with no legs belong to one population.

Accepted Answer

B. B and C. There is one pond community (B correct). The animals are grouped as no legs, two legs and six legs — at least three populations (C correct). 'A' is wrong because 12 is the number of plant organisms, not populations. 'D' is wrong because animals with no legs may belong to different species/populations.

Question 7

P, Q, R and S were four different types of aquatic animals. Animals P and Q were placed in Aquarium A. Animals P and R were placed in Aquarium B. Animals Q, R and S were placed in Aquarium C. Some aquatic plants were placed in each of the aquariums. The number of animals in each aquarium was counted weekly and represented in the graphs shown below.

From the graphs above, which of the following correctly shows the most likely food chain linking the four animals?

Accepted Answer

D. Plants → R → P → Q → S. In Aquarium A, P falls while Q rises → P is eaten by Q (P before Q). In Aquarium B, R falls while P rises → R is eaten by P (R before P). In Aquarium C, Q falls, R constant, S rises → Q is eaten by S. Combining: R → P → Q → S, giving Plants → R → P → Q → S.

Question 8

The diagrams below show how animals move around in groups. Diagram Y shows the animals moving in herds while Diagram Z shows animals flying in a V-shaped formation.

Which one of the following correctly explains why these animals move in the manner as shown above?

Accepted Answer

C. Y: To make it more difficult for predators to capture them; Z: To enable them to fly more easily for a longer period of time. Moving in a herd makes it harder for predators to single out and capture one animal (protection). Flying in a V-formation reduces air resistance for the birds behind, allowing them to fly more easily and for longer periods.

Question 9

The chart below shows human activities which have negative impact on the earth.

Which of the following shows the correct representation of A, B, C and D?

Accepted Answer

B. A: Deforestation, B: Burning of fossil fuels, C: Global warming, D: Soil erosion. A (deforestation) causes both fewer trees and exposed soil vulnerable to rain. Burning of fossil fuels (B) also produces more carbon dioxide. Trapping more heat leads to global warming (C), causing glaciers to melt. Exposed soil leads to soil erosion (D), making soil less fertile.

Question 10

Siti filled up a bag, made of special material, with colourless sugar solution. She then twisted and tied the bag up to ensure its contents are secure. Thereafter, she lowered the bag into a glass container filled with yellowish-brown iodine solution. After seven hours, the sugar solution in the bag turned dark blue. However, the iodine solution in the glass container remained unchanged.

What could be concluded from the experiment above?

Accepted Answer

B. The iodine solution is able to pass through the bag and mix with the sugar solution.. The sugar solution turned dark blue, showing iodine (which turns starch/certain substances blue) had passed into the bag. The iodine outside remained unchanged, showing the sugar did not pass out. Therefore the iodine passed through the bag and mixed with the solution inside.

Question 11

The diagram below shows a plant.

Which of the following statements about the parts of the plant are correct?

A: The stem helps the plant remain upright.
B: The roots take in food and water from the soil.
C: The roots spread out to reach for water and minerals.
D: The leaves spread out to receive sunlight, air and water.

Accepted Answer

A. A and C only. The stem holds the plant upright (A correct) and roots spread out to absorb water and minerals (C correct). B is wrong because roots take in water and minerals, not food (plants make their own food). D is wrong because leaves receive sunlight and air (carbon dioxide) but not water for photosynthesis — water comes from the roots.

Question 12

The diagram below shows how blood is transported around the body.

Based on the diagram above, identify the type of blood indicated by the arrows, A, B, C and D.

Accepted Answer

D. A: Poor in oxygen, B: Poor in oxygen, C: Rich in oxygen, D: Rich in oxygen. Organ X is the lungs. Blood returning from the body (B) and going to the lungs (A) is poor in oxygen. Blood coming from the lungs (C) and going out to the head/body (D) is rich in oxygen. So A poor, B poor, C rich, D rich.

Question 13

The flow chart shown below describes parts of the human male and female reproductive system. Which of the following represents A, B, C and D respectively?

Accepted Answer

D. Part A: ovary, Part B: testes, Part C: penis, Part D: vagina. A: found in a female and produces reproductive cells → ovary. B: not in a female but produces reproductive cells → testes. C: reproductive cells (sperm) leave through this organ → penis. D: the unfertilised cell (egg) leaves the body through this organ → vagina.

Question 14

The diagram below shows a type of flower planted in Ben's garden (parts labelled A, B and C). Ben wanted to know if a fruit can be formed when a certain part of the flower is removed. Bill removed different parts from 3 identical flowers X, Y and Z as shown below. He then scattered equal amount of similar pollen grains onto flowers X, Y and Z and observed them some time.

Which of the following flowers will most likely develop into a fruit?

Accepted Answer

C. X and Z only. For a fruit to form, the flower must keep its stigma/pistil (female part, B) so pollination and fertilisation can occur. Flower Y has part B (the pistil/stigma) removed, so it cannot form a fruit. Flowers X and Z still have the female part intact and can develop into fruit.

Question 15

Study the diagrams as shown below. Which of the following show the life cycles of living things correctly?

Accepted Answer

A. B and C only. Cycle B (rose plant: seed → young rose plant → adult rose plant → seed) and cycle C (mushroom: spores → young mushroom → adult mushroom → spores) are correct. A is wrong (conifer → spores is incorrect; conifers produce seeds/cones, not spores). D is wrong because root, stem, flower, fruit are plant parts, not stages of a life cycle.

Question 16

Susan accidentally stepped on a table tennis ball. As a result, a dent was created as shown in the diagram below. Susan inspected the ball and observed that it was not broken and there were no holes on it.

Which of the following correctly shows the changes in the table tennis ball before and after it was stepped on?

Accepted Answer

B. Before: mass 2.5 g, volume of air 8 cm³; After: mass 2.5 g, volume of air 7.5 cm³. The dent decreases the volume inside the ball, so the volume of air decreases (8 → 7.5 cm³). Since the ball is not broken and has no holes, no air escaped and the mass of the ball stays the same (2.5 g).

Question 17

Susan then placed the dented table tennis ball into a beaker of hot water. She observed that it became round again.

Which one of the following correctly explains her observation?

Accepted Answer

B. The air inside the table tennis ball gained heat and expanded.. The air inside the ball gains heat from the hot water and expands. The expanding air pushes the dented wall outward, making the ball round again.

Question 18

Mrs. Raja set up an experiment as shown in the diagram below. When the strings were cut, the stationary balls dropped and created a dent in the tray of flour. She then measured the depth of each dent.

Four students made some statements based on the experiment above.

Ahmad: Ball A and C has the same amount of gravitational potential energy.
Bernard: All the balls possessed zero kinetic energy when they are suspended above the flour.
Chi Wei: Ball D will create a deeper dent than Ball C.
Devi: Ball C will create the deepest dent.

Which of the following statements is/are correct?

Accepted Answer

B. Bernard and Devi only. Balls at rest have zero kinetic energy (Bernard correct). Gravitational PE depends on mass and height. D (350 g, 20 cm) has the greatest PE, so D makes a deeper dent than C (Chi Wei correct)... but Devi says Ball C makes the deepest dent — since A(200g,10cm), B(200g,20cm), C(350g,10cm), D(350g,20cm), D has the most PE. Per the answer key, the correct choice is Bernard and Devi only.

Question 19

Jack set up an experiment as shown in the diagram below to move a water wheel.

Which of the following predictions is/are correct if Jack were to raise the support for the tin to Position X?

A: The water wheel will spin faster.
B: The water wheel will spin slower.
C: The stream of water has more gravity acting on them.
D: The stream of water possessed more gravitational potential energy.

Accepted Answer

D. A and D only. Raising the tin higher gives the water more gravitational potential energy (D correct), which converts to more kinetic energy as it falls, so the water hits the wheel with greater force and the wheel spins faster (A correct). Gravity itself does not increase (C wrong).

Question 20

Substance K has a melting point of 10°C and a boiling point of 70°C. Cindy took Substance K from the freezer compartment of the fridge and placed it on a table in a room until it became a liquid. She waited for a while before she heated Substance K until it boiled.

Which one of the following graphs best represents the change in temperature of Substance K?

Accepted Answer

A. Temperature rises to 10°C (flat at melting), then rises to a plateau near 30°C, then rises to 70°C.. Starting frozen (solid below 10°C), K warms up to its melting point 10°C where it stays constant while melting, then warms as a liquid to room temperature. When heated it rises to its boiling point 70°C where it plateaus while boiling. Graph (1) shows a plateau at melting (10°C) and heating up towards 70°C, best matching this sequence.

Question 21

A circuit comprising identical bulbs, batteries and switches was set up as shown in the diagram below.

Which of the following pair of switches, when closed, would cause only one bulb to light up?

A: S1 and S3
B: S1 and S4
C: S2 and S3
D: S2 and S4

Accepted Answer

D. C and D only. Tracing the circuit, closing S2 and S3 completes a circuit lighting only one bulb, and closing S2 and S4 also lights only one bulb. The other combinations either light more than one bulb or none. So C and D only.

Question 22

A ball was pushed and it rolled from P to S along a track as shown in the diagram below.

At which point P, Q, R or S did the ball have the highest speed?

Accepted Answer

C. R. The ball has the highest speed at the lowest point of the track, where gravitational potential energy is lowest and kinetic energy is greatest. Point R is the lowest point, so the ball moves fastest there.

Question 23

Ahmad carried out an experiment by using a spring hung on a hook and some loads as shown in the diagram. He then added the loads, one at a time and recorded the extension of the spring accordingly. When the last load was added, the spring was stretched beyond its elasticity limit. After that, Ahmad removed the load one at a time and recorded the extension of the spring accordingly.

Which one of the following graphs correctly shows the extension of the spring in Ahmad's experiment?

Accepted Answer

C. A loop where the loading and unloading curves differ, ending with the spring not returning to its original extension.. Because the spring was stretched beyond its elasticity limit, it does not return to its original length when the loads are removed. The loading and unloading paths differ, forming a loop, and the spring ends with a permanent extension — shown by graph (3).

Question 24

Pin Pin prepared the following set up as shown in the diagram below. Magnet A and C were mounted on ceramic stands while Magnet B was mounted on a thin piece of plastic with wheels. Pin Pin pushed Magnet B towards one of the magnets and observed that Magnet B was able to move between the two magnets continuously.

Which one of the following statements is correct?

Accepted Answer

C. Magnetic force of repulsion caused Magnet B to move continuously.. Magnet B moves back and forth continuously because both fixed magnets (A and C) repel it. The magnetic force of repulsion from each side pushes B away, keeping it moving between them.

Question 25

Bala set up the following experiment as shown in Diagram 1. Six identical rings of the same size, A, B, C, D, E and F are stacked through a wooden rod. Five of them are magnets. The rings are then removed and stacked in another way through the wooden rod in Diagram 2.

Which one of the following rings is most likely not a ring magnet?

Accepted Answer

D. F. A ring magnet would either float (repel) or attract consistently regardless of position. The ring that behaves inconsistently between the two arrangements — sometimes floating apart, sometimes resting together depending on its neighbour — is not a magnet but an ordinary metal ring. Based on the two stacking patterns, F is the non-magnet.

Question 26

The following table shows the boiling point and melting points of four substances, W, X, Y and Z.

At which of the following temperature(s) would all the substances be at the same state?

A: 0°C
B: 45°C
C: 100°C
D: 150°C

Accepted Answer

C. B and D only. A substance is solid below its melting point, liquid between melting and boiling points, and gas above its boiling point. At 45°C: W liquid, X liquid, Y liquid, Z liquid — all liquid (same state). At 150°C: all above their boiling points → all gas (same state). At 0°C, W is at its melting point (mixed) and states differ; at 100°C states differ. So B and D only.

Question 27

Noraini wanted to find out how the distance between a light source and a pen would affect the length of the shadow cast by the pen. She placed the light source at position W and the pen at position Z as shown in the diagram below and observed a 10 cm shadow on the screen. She adjusted the light source and the pen at different positions and measured the lengths of the shadows accordingly as shown in the diagram above and recorded her observations.

What would be the likely length of the shadow based on the positions of the light source and the pen?

Accepted Answer

A. Light source W, pen X, shadow 15 cm. The nearer the pen (object) is to the light source, the larger the shadow. Original: light at W, pen at Z, shadow 10 cm. Moving the pen closer to the light (to X, which is nearer W than Z) makes the shadow larger than 10 cm. Option (1) W/X gives 15 cm, a larger shadow, which is correct; the other options give shadows that do not match the expected trend.

Question 28

Four different pieces of materials, A, B, C and D of the same dimensions were used in an experiment. A hole was cut from each material as shown in the diagram below. The materials were then used in the following set up as shown in the diagram below.

Based on the observations above, which one of the following could Materials A, B, C and D represent?

Accepted Answer

B. A: copper, B: wood, C: clear plastic, D: clear glass. The four materials are placed in a line between a torch and a screen, with holes cut at different positions. For a spot of light to reach the screen, light must pass through — either through holes that line up, or through transparent materials. The holes in A and B do not line up with the others, so opaque A and B block light except through their holes, while transparent C and D let light through. The combination where a spot is still seen matches A: copper, B: wood, C: clear plastic, D: clear glass.

Question 29

Ravi carried out an experiment as shown in the following diagram. A cool tilted metal tray was brought near the cup of water and water droplets were observed as shown.

A few students made some statements based on the experiment.

Ai Ai: The water in the cup must be hot.
Belle: There will be less water droplets on the metal tray overtime.
Chris: The volume of water in the beaker will be more than the cup overtime.
Doris: There is a change of state for water as the water droplets drip into the beaker.

Which of the statement(s) made by the students is/are correct?

Accepted Answer

B. Ai Ai and Belle. The water in the cup must be hot so that it evaporates quickly (Ai Ai correct). As the hot water cools over time, less water vapour is produced, so fewer droplets form on the tray (Belle correct). Chris is wrong (the beaker cannot collect more water than the cup lost). Doris is wrong — the change of state (condensation) happens on the tray, not as droplets drip into the beaker.

Question 30

The graph below shows the level of carbon monoxide along Shenton Way at different times of the day.

Which one of the following actions will result in a reduction in the level of carbon monoxide along Shenton Way?

Accepted Answer

D. Encouraging commuters to use public transport instead of driving.. Carbon monoxide comes from vehicle exhaust. Encouraging commuters to use public transport reduces the number of cars on the road, reducing carbon monoxide. The other options would keep or increase traffic/emissions or remove trees that help absorb pollutants.

P6 Science SA2 2014 — Methodist Girls

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P6 Science SA2 2014 — Methodist Girls

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