Question 1

Study the animals in groups A and B below. Which of the following is correct? A tick (√) shows the presence of the characteristic(s) of the animals.

Accepted Answer

B. Group A, has body covering of feathers, has wings. Group A shows a cockatoo and a heron — both birds with feathers and wings. Group B shows a polar bear and a squirrel — both mammals with fur and no wings.

Question 2

Which of the following statements about fungi are true?
A Yeast is a type of fungi.
B Fungi reproduce by spores.
C Fungi are not made of cells.
D Fungi do not have chloroplasts.

Accepted Answer

C. A, B and D only. Yeast is a fungus (A true). Fungi reproduce by spores (B true). Fungi ARE made of cells (C false). Fungi lack chloroplasts and cannot photosynthesise (D true). Thus A, B and D are correct.

Question 3

Observations made on animals P and Q are recorded in the table below. Which of the following represents animals P and Q correctly?

Accepted Answer

C. P: cockroach, Q: frog. Animal P has a 3-staged life cycle, lays eggs on land, and the young resembles the adult — matches a cockroach (egg → nymph → adult, incomplete metamorphosis). Animal Q has a 3-staged life cycle but does NOT lay eggs on land and young does NOT resemble adult — matches a frog (egg → tadpole → adult, eggs laid in water, tadpole does not resemble adult frog).

Question 4

Bethany investigated the conditions needed for the germination of green beans. She prepared three set-ups, A, B and C, each containing same amount of cotton wool and the same number of green beans. The table shows the conditions each set-up was exposed to. Bethany recorded the observations on the green beans after five days. Which of the following observations correctly matches the reason?

Accepted Answer

B. Green beans in set-up A germinated. Reason: Air, water and warmth needed for germination were present.. Germination requires water, air and warmth — not light. Set-up A (damp cotton wool, 30°C, light) has all three required conditions present, so beans germinate; the correct reason cites air, water and warmth. Light is not a requirement, so options A and C are wrong. D is wrong because the reason should mention 'no water and warmth' — but the key missing factor in C is warmth, not light.

Question 5

The diagrams below show the reproductive systems of a plant and human. Which of the following represent the parts involved in producing the male reproductive cells?

Accepted Answer

A. A and C. In the plant, part A is the anther (or stamen) that produces pollen grains (male reproductive cells). In the human male reproductive system, part C is the testis which produces sperm (male reproductive cells). B (stigma/pistil) and D (sperm duct/urethra) are not the producing organs.

Question 6

The diagram below shows how a fruit is developed from a flower: flower → Process X → Process Y → fruit. Which of the following correctly identifies processes X and Y?

Accepted Answer

D. X: pollination, Y: fertilisation. For a flower to develop into a fruit, pollination must first occur (pollen transferred from anther to stigma), followed by fertilisation (male and female gametes fuse). The ovary then develops into a fruit.

Question 7

The diagrams below show two flowers, G and H, from the same type of plant. Which is / are the arrow(s) that represent(s) the process pollination?

Accepted Answer

A. C only. Pollination is the transfer of pollen from the anther to the stigma. Arrow C goes from the anther of Flower G to the stigma of Flower H — this is cross-pollination. Arrow D goes from stigma to anther, which is not pollination. Arrows A and B (within G) and E (within H) are from anther to anther — not stigma — so are not pollination.

Question 8

Sarah wanted to find out if overcrowding affects plant growth. The table shows four different set-ups, P, Q, R and S, each containing the same amount of soil. She watered each set-up with the same amount of water daily. Which set-ups, P, Q, R and S, should Sarah use to ensure a fair test?

Accepted Answer

C. Q and S only. To test overcrowding, only the number of seeds per pot (or pot size relative to seeds) should differ; everything else must be the same. Q has 3 seeds in a small pot (crowded), in garden at 35°C. S has 3 seeds in a larger pot (not crowded), in garden at 35°C. Q and S share the same location, temperature and number of seeds but differ only in pot size — testing overcrowding. P differs in location and number of seeds. R differs in temperature from Q. Therefore Q and S form the fair test.

Question 9

The chart below shows the amount of food digested in various parts of the human digestive system six hours after a meal. Based on the graph above, which one of the following best represents W, X, Y and Z respectively?

Accepted Answer

A. W: stomach, X: large intestine, Y: small intestine, Z: mouth. Six hours after a meal, most of the food has moved past the mouth and stomach and is being digested in the small intestine. The bar chart shows Y as the tallest (most food digested = small intestine), W and Z as small bars (stomach and mouth respectively, since most has passed), and X as zero (large intestine, which absorbs water rather than digests food). Hence W=stomach, X=large intestine, Y=small intestine, Z=mouth.

Question 10

Norris prepared set-ups A, B and C using the same type of plant. She removed some roots from the plants in set-ups B and C and removed some leaves from the plant in set-up C as shown in the diagrams below. She observed the volume of water left in each set-up over a period of one week. Which of the following graphs best represents the results obtained for the three set-ups, A, B and C?

Accepted Answer

D. Set-up A loses the most water; Set-up B and C lose less. Plants lose water via transpiration through their leaves; roots take up water. Set-up A (all roots and leaves intact) absorbs and transpires the most water — water level drops fastest. Set-up B (some roots removed) absorbs less water, so transpires less. Set-up C (roots AND leaves removed) absorbs and transpires the least — water level drops slowest. Graph showing fastest fall for A and slowest fall for C is correct.

Question 11

Which one of the following parts is found in a root cell but not in a cheek cell?

Accepted Answer

A. cell wall. Root cells are plant cells and have a cell wall; cheek cells are animal cells and lack a cell wall. Both have cytoplasm and cell membrane. Chloroplasts are absent in root cells (no light reaches them).

Question 12

Denise prepared set-ups A, B, C and D as shown below. She measured the concentration of carbon dioxide in the water in each test-tube before the experiment and two hours later. In which test-tube would there be a decrease in the concentration of carbon dioxide after two hours?

Accepted Answer

C. Set-up C. Carbon dioxide decreases only when a plant photosynthesises (uses CO₂). Set-up C contains a water plant exposed to light and is not covered by black opaque paper — so photosynthesis occurs and CO₂ in the water decreases. A is covered by black opaque paper (no light, no photosynthesis). B is also covered. D has no plant.

Question 13

Gabi wanted to construct a flying model as shown in the diagram below. She wanted to conduct a test launch where the flying model would fly to a height of one metre when filled with water and that it would not be damaged when it landed on the ground. Which of the following properties must she consider while selecting the materials to build her flying model?

Accepted Answer

A. Strength and waterproof.. The model must hold water without leaking (waterproof) and must not break on landing (strong). Heat and electricity conductivity are irrelevant to a water-powered rocket.

Question 14

A sealed container holds 700 cm³ of oil and 300 cm³ of air as shown below. Another 200 cm³ of oil is removed and 100 cm³ of air is added to the container through the pump. What is the final volume of air in the container?

Accepted Answer

C. 500 cm³. The container is sealed, so total volume is fixed at 700 + 300 = 1000 cm³. After removing 200 cm³ of oil, oil = 500 cm³. Air now occupies 1000 − 500 = 500 cm³. Even though 100 cm³ of extra air is added, gas fills all available space, so final air volume = 500 cm³.

Question 15

Tim had a bag of identical marbles. He wanted to find the volume of each marble. He filled a measuring cylinder with water as shown in diagram below. Tim then put ten marbles in the measuring cylinder of water. His result is shown below. Based on Tim's experiment, which of the following is correct?
A Marbles occupy space.
B Water has no definite volume.
C The volume of each marble is 5 cm³.

Accepted Answer

A. A only. Before marbles: water level at 10 cm³ (or similar). After 10 marbles added: water level rises (e.g., to about 18 cm³). The level rise shows marbles displaced water → marbles occupy space (A true). Water DOES have a definite volume (B false). Reading the diagrams shows the water rose by less than 10 cm³ for 10 marbles, so each marble's volume is not 5 cm³ (C false). Only A is correct.

Question 16

The table below shows the freezing point and boiling point of three substances, X, Y and Z. Which of the substances, X, Y or Z, is/are liquid(s) at 90°C?

Accepted Answer

C. Y and Z only. A substance is liquid between its freezing and boiling points. X: freezes 6°C, boils 80°C — at 90°C X is a gas. Y: freezes 17°C, boils 118°C — at 90°C Y is a liquid. Z: freezes 43°C, boils 181°C — at 90°C Z is a liquid. So Y and Z only are liquids at 90°C.

Question 17

Dora wanted to investigate the electrical conductivity of rods A, B, C and D. She constructed the circuit as shown below. She recorded her observation below when she removed certain rods and closed the switch. Based on her observation, which of the following conclusions about the rods A, B, C and D is correct?

Accepted Answer

D. Conductors: B, D; Insulators: A, C. The rods are in parallel. Remove D → bulb lights → at least one of A, B, C is a conductor. Remove B and C → bulb lights → A or D conducts; since D is still in, D could be the conductor. Remove B, C and D → bulb does NOT light → A alone cannot conduct, so A is an insulator. Remove A, B and D → bulb does NOT light → C alone cannot conduct, so C is an insulator. Therefore A and C are insulators, B and D are conductors.

Question 18

The circuit below consists of identical bulbs, B1, B2, B3 and B4, all lit up. Which of the following is likely to be observed when only one of the bulbs in the above circuit is fused at one time?

Accepted Answer

D. B2 or B4 fused → smallest 0, largest 3. B1 and B4 are in series with the parallel pair B2/B3. If B1 OR B4 fuses, the whole circuit breaks — all bulbs go out → 0 lit. If B2 fuses, B3 still lights (parallel branch), and B1, B4 still light → 3 lit. If B3 fuses, B2 still lights and B1, B4 still light → 3 lit. So 'B1 or B4 fused' gives 0 only (not 3), and 'B2 or B3 fused' gives 3 only (not 2). Option (4): 'B2 or B4' — if B2 fuses → 3 lit (largest); if B4 fuses → 0 lit (smallest). Matches.

Question 19

A steel bar XY was magnetised using the 'stroke' method as shown in Diagram 1 below. Diagram 2 shows the magnetic poles of XY after it was magnetised. Another steel bar below was magnetised using two magnets as shown in Diagram 3. Identify the poles at A and B used to magnetise the steel bar respectively.

Accepted Answer

B. Poles at A: S, Poles at B: N. In stroke magnetisation, the pole produced at the end where the stroking pole leaves is OPPOSITE to the stroking pole. Diagram 1: an S pole is stroked from X to Y leaving at Y, producing N at Y and S at X (Diagram 2 confirms S at X, N at Y). For Diagram 3, the steel bar shows poles N-S-N-S, meaning the two magnets were stroked outward from the middle. The pole that produced N (left end) must have been S (so A=S); the pole that produced S at far right must have been N (so B=N).

Question 20

Ali, Beth, Cailing, and Devi prepared the following set-ups using identical boxes A and B as shown below. The boxes were placed at the same starting point on the ramps. They observed that box B would slide down the ramp but box A remained stationary. The pupils made the following statements: Ali — The gravitational force acting on both boxes was the same. Beth — The gravitational force acting on box B was more than that of box A. Cailing — The surface of the ramp where box A was placed on was smoother. Devi — The frictional force between box B and the surface of the ramp was less than that of box A and the surface of the ramp. Which of the pupils made the correct statements?

Accepted Answer

B. Ali and Devi. Boxes A and B are identical so gravitational force on each is the same (Ali correct, Beth wrong). Box B slid down while Box A stayed — this implies less friction on Box B (its ramp surface is smoother), so Devi is correct and Cailing is wrong (she has it the opposite way around).

Question 21

Which of the following arrows shows the direction of frictional force acting on a ladder which is leaning against the wall?

Accepted Answer

B. Upward arrow at wall + leftward arrow on floor (toward wall). A ladder leaning on a wall tends to slip: its top would slide DOWN the wall and its bottom would slide AWAY from the wall (outwards on the floor). Friction opposes motion, so friction at the top wall contact acts UPWARD, and friction at the floor contact acts TOWARD the wall (inwards).

Question 22

Stella carried out an experiment to find out which rubber ball, P, Q or R, travelled the furthest distance when it was rolled down the same ramp as shown below. The rubber balls were identical in size but of different masses. For each ball, she repeated the experiment three times. She recorded the distance travelled by each ball in the table below. However, she did not carry out a fair test when conducting the experiment with ball R. Based on the results of the above experiment, which of the following statements is/are most likely to be true?
A The amount of gravitational force acting on ball Q was the least.
B The way she released ball R was not the same for all the three tries.
C Ball R was released at different positions on the ramp at each repeated experiment.

Accepted Answer

C. B and C only. Ball Q travelled the furthest on average (182.3 cm) implying greater mass → MORE gravitational force, not less, so A is false. Ball R's distances vary wildly (90, 125, 680) — this inconsistency means the experiment with R was not fair. Both releasing the ball with different force/method (B) and starting from different heights on the ramp (C) would explain the inconsistent results — both statements are likely true.

Question 23

A light sensor is used to count the number of wooden blocks on a moving belt in a factory as shown in the set-up below. The belt moves at a constant speed. The workers plotted the results in the graph shown below. Based on the graph above, how many wooden blocks were counted in five seconds?

Accepted Answer

B. 3. Each time a wooden block passes between the light source and the sensor it blocks the light → drop in light intensity. Each high-to-low dip corresponds to one block. Counting the dips within the first 5 seconds of the graph gives 3 wooden blocks.

Question 24

The diagram below shows a lamp post. The distance from A to B is identical to the distance from B to C. David walked under the lighted lamp post from B to C, then C to A passing B again. He increased his speed while walking from B to A. Which one of the diagrams below shows the changes in the length of the boy's shadow over the period of time?

Accepted Answer

D. Up then down then up (slower then faster). Under the lamp at B the shadow is shortest. Walking from B to C the shadow lengthens (rises). At C the boy turns and walks back from C to A. Walking from C to B the shadow shortens (falls). At B the shadow is short again, then walking faster from B to A the shadow lengthens again, and because he is moving faster, the rise is steeper. The graph that goes up, then down to a minimum at B, then up again steeply is correct.

Question 25

Emma carried out an experiment with the two set-ups X and Y as shown below. She used identical containers and burners for the two set-ups. In set-up X, she placed a blob of wax on a surface which was placed 5 cm above the base of the container. In set-up Y, she placed the same amount of wax on an identical surface. The surface was raised 15 cm above the base of the container. She recorded her observation in the table. Based on the results of the experiment, Emma attempted to prepare fried ice cream. She prepared the flour dough using a mixture of water, baking soda and flour. She coated the identical ice creams with different amounts of flour dough as shown. Then they were deep fried using the same amount of heat for ten seconds until golden brown. Emma observed that one of the ice creams melted after ten seconds. Which one of the following is correct?

Accepted Answer

B. Ice cream A melted. There was less air in the dough. Thus, the ice cream gained heat faster.. The wax experiment showed that a thicker air layer (15 cm) took longer to transfer heat — air is a poor conductor. Applied to fried ice cream: the dough with MORE air bubbles around it (more insulating air pockets) protects the ice cream best, while the one with LESS air (denser dough) lets heat through faster and melts first. Ice cream A has thinner dough with fewer air bubbles, so it melted first because there was less insulating air. Option B captures this correctly.

Question 26

Alison prepared the set-up shown below using the same amount of wax to hold the identical thumbtacks on the materials A and B respectively. The materials are of identical length. The thumbtacks were placed at equal distance away from the heat source. Alison observed the thumbtack on material B drop off first. Next, she wrapped a piece of paper round materials A and B as shown below and put over a heat source. She observed the piece of paper after three minutes. Which of the following provides the correct observation and explanation?

Accepted Answer

B. The paper on material A would burn. Material A conducted heat away from the paper more slowly.. The thumbtack on B dropped off first → B is the BETTER heat conductor. In the paper-wrap experiment, the better conductor (B) conducts heat AWAY from the paper quickly so the paper above B does NOT burn, while the poorer conductor (A) lets heat build up in the paper so the paper above A burns first. Therefore paper on A burns because A conducts heat away more slowly.

Question 27

Linda designed a model as shown below. The cup is fixed onto a wooden rod which can move at pivot A. Water from a tank is dripped into the cup. When the cup is filled up with water, it moved down, causing the other end of the rod to hit against the wooden block. Which of the following should Linda change to enable her model to produce a louder sound?
A increase the size of the hole
B increase the size of the wooden ball
C change the wooden ball to a metal ball
D increase the height of the tank above the wooden container

Accepted Answer

C. A and D only. A louder sound from the hammering action comes from greater force/energy delivered. Increasing the hole size (A) lets water in faster, filling the cup quicker so it falls harder — louder. Increasing the height of the tank (D) increases the speed/pressure of water entering the cup, again increasing force when it tips — louder. Changing the wooden ball or its size (B, C) does not affect the rod–block strike at all (the ball is not involved in the sound mechanism described). So A and D only.

Question 28

Trina conducted an experiment using springs X and Y. She hung different numbers of weights one at a time and recorded the length of the springs. Her results were shown in the graph. The two springs, X and Y, were used to make the two dish racks, which hold identical number of plates as shown. When Trina removed three plates from the top of dish rack 1, the metal disc moved up from P to Q. She also removed three plates from dish rack 2. Based on the graph and the information provided, which of the following statement(s) is / are true when three plates were removed from the two dish racks?
A The metal discs on both racks have gravitational potential energy and elastic potential energy.
B The metal disc on dish rack 1 will have less gravitational potential energy than the metal disc in dish rack 2.
C The metal discs for both racks moved up because the stretched springs exerted a pulling force on the metal discs.
D The metal disc moved up as the weight of the plates is greater than the elastic spring force acting on the metal discs.

Accepted Answer

C. B and C only. Removing plates reduces the load, allowing the stretched springs to contract, pulling the metal disc upward — so C is true. Spring Y is stiffer, so for the same reduction in load, spring Y contracts less than spring X, meaning the metal disc in dish rack 1 (spring X) rises HIGHER than that in dish rack 2 (spring Y); but the dish rack 1 disc starts lower, so after lifting it is still lower than dish rack 2's disc — so its gravitational PE is less than dish rack 2's, making B true. A is false because once the spring contracts it is no longer stretched, so no elastic PE remains. D is wrong because the disc moves up when the spring force EXCEEDS the weight of plates.

P6 Science SA2 2020 — Raffles Girls

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