Question 1

The diagram below shows two living things. Which statement is correct?

Accepted Answer

A. One contains chlorophyll while the other does not.. The fern contains chlorophyll (it is a plant and photosynthesises) while the baby does not. Both living things reproduce, respond to stimuli, and take in both oxygen (for respiration) and carbon dioxide (plants for photosynthesis), so only option A is correct.

Question 2

Study the flowchart. [Flowchart: organisms → A? yes → bird, no → B? yes → insect, no → mammal.] Which row shows the characteristics represented by A and B? [Table options: (1) A: Has a beak, B: Has moist skin; (2) A: Has feathers, B: Has six legs; (3) A: Has 3 body parts, B: Lay eggs; (4) A: Has wings, B: Has 3 body parts.]

Accepted Answer

B. Has feathers / Has six legs. To uniquely identify a bird, 'has feathers' is the only characteristic exclusive to birds (beaks and wings also occur in other animals). After removing birds, 'has six legs' uniquely identifies insects from mammals. So A = feathers and B = six legs.

Question 3

Which of the following is correct for both the cockroach and mosquito?

Accepted Answer

B. Both their life cycles start with an egg.. Both cockroach (incomplete metamorphosis) and mosquito (complete metamorphosis) life cycles begin with the egg stage. Cockroach nymphs look like adults but mosquito larvae do not; mosquito young live in water while cockroach young live on land, so only B is true for both.

Question 4

The diagram shows four different cells. Which row classifies the cells correctly? [Table: (1) Animal: B, Plant: A,C,D; (2) Animal: A,C, Plant: B,D; (3) Animal: B,C, Plant: A,D; (4) Animal: B,C,D, Plant: A.]

Accepted Answer

C. Animal: B, C; Plant: A, D. Cells A and D have a defined rectangular outline with a cell wall (plant cells). Cell B is an irregular animal cell and Cell C is a sperm cell (animal). So animal cells = B and C; plant cells = A and D.

Question 5

Study the fruit. Below are some items provided: A electronic balance, B ruler, C beaker of water, D fan. Which of the following item(s) should be used to determine if the fruit is dispersed by wind?

Accepted Answer

C. B and D. To test wind dispersal, you need a fan (D) to provide wind and a ruler (B) to measure how far the fruit is blown. The balance is not needed and water (C) would test water dispersal.

Question 6

The diagrams below show the reproductive systems of a human and a plant. Which parts produce the female reproductive cells?

Accepted Answer

A. Q and W. Female reproductive cells (eggs/ovules) are produced in the ovary of both humans and plants. Q is the human ovary and W is the plant ovary, so the answer is Q and W.

Question 7

The diagram shows the human skeletal system. Which cell part has a similar function to the skeletal system?

Accepted Answer

B. Cell wall. The skeletal system gives the body shape and support. In a plant cell, the cell wall performs the same supportive/structural function.

Question 8

Plant T grows in a desert. It is able to store air in the leaves. Bala observed the cells of a leaf of plant T during day and night as shown. Based on Bala's observations, which statement shows how plant T is adapted for photosynthesis in a desert?

Accepted Answer

D. Plant T takes in carbon dioxide in the night and photosynthesises in the day.. The stomata are closed during the hot day to reduce water loss and open at night when it is cooler. Plant T therefore takes in and stores carbon dioxide at night, and uses the stored CO₂ together with sunlight to photosynthesise during the day.

Question 9

Ali inflated two balloons to the same size with different methods. He used an air pump to pump air into balloon A and blew air into balloon B. Which is the correct change in the composition of gases inside the balloons?

Accepted Answer

A. There is greater volume of oxygen in A than B.. Atmospheric air (balloon A) has about 21% oxygen, whereas exhaled air (balloon B) has used up some oxygen during respiration. Therefore balloon A contains a greater volume of oxygen than balloon B.

Question 10

Jane wanted to find out whether the presence of water plants affects the amount of carbon dioxide in the pond. She used the set-up shown. Which of the following set-ups should Jane use as a control for her experiment? [Options: (1) tank with fish and water plants; (2) tank with water plants only; (3) tank with fish and pond water only; (4) tank with pond water only.]

Accepted Answer

D. Tank with pond water only. The variable being tested is the presence of water plants, so the control set-up must be identical except that the water plants are absent — pond water only with nothing else added.

Question 11

The diagram below shows a pond habitat. Based on the diagram, which of the following is true?

Accepted Answer

B. There are seven populations in the pond habitat.. Counting the different species shown (land plants, caterpillars, butterflies, water lilies/aquatic plants, tadpoles, fish, plus another aquatic plant and consumer) gives seven distinct populations in the habitat.

Question 12

Study the food web below. In the colder months of the year, all of organism R will migrate to another location with higher temperature. Which population will be the most affected when organism R are gone?

Accepted Answer

D. T. T feeds only on R, so if R migrates away, T loses its only food source and will be most affected. Q and S have alternative food sources or are producers.

Question 13

The diagram below shows a group of organisms standing together in their habitat with their young in the centre of the group. Below are some adaptations and possible reasons stated by some students on how the organisms adapt to the environmental conditions stated above. [Table: A — Densely packed feathers / Trap air to reduce heat loss; B — Webbed feet / Swim faster from predators; C — Standing closely packed together / Reduce exposure to wind and heat loss; D — Standing with young in centre / Protect young from predators.] Which student(s) is/are correct?

Accepted Answer

B. A and C only. The environmental conditions (0 °C, 180 km/h wind) are about cold and wind, so adaptations A (trap air to reduce heat loss) and C (huddling to reduce wind exposure and heat loss) are correct. B is about predators (not the stated environmental conditions) and D's reason should be to keep the young warm, not protect from predators.

Question 14

What would be the most possible effect after large areas of forests are removed?

Accepted Answer

C. There will be more carbon dioxide in the air.. Removing forests means fewer plants to take in carbon dioxide for photosynthesis, so the amount of CO₂ in the air will increase.

Question 15

A fisherman pulls a net full of fish onto his boat. Based on the properties shown, which material is most suitable for making the net? [Table: (1) A — strong ✓, waterproof ✗, flexible ✗; (2) B — strong ✗, waterproof ✓, flexible ✗; (3) C — strong ✗, waterproof ✓, flexible ✓; (4) D — strong ✓, waterproof ✗, flexible ✓.]

Accepted Answer

D. Material D (strong and flexible). A fishing net must be strong (to hold heavy fish) and flexible (to be cast and pulled). Waterproofing is not essential. Only material D is both strong and flexible.

Question 16

Peter poured an equal amount of water into three identical measuring cylinders. Objects X, Y and Z were placed in the measuring cylinders as shown in the diagram. Which statement is correct?

Accepted Answer

C. The volume of object Y is greater than the volume of object Z.. Volume of Y = 75 − 50 = 25 cm³; volume of Z = 85 − 75 = 10 cm³. Therefore Y (25 cm³) has a greater volume than Z (10 cm³). Mass cannot be determined from volume alone, and X's volume is unknown (50 cm³ is the water + X reading).

Question 17

A container was filled with a substance M. A stopper was then used to seal the air-tight container. A 10 kg weight was placed on the stopper and the stopper moved downwards. What could be a possible reason for this observation?

Accepted Answer

D. Substance M has no definite volume.. If the stopper moves downwards in a sealed container, the substance M inside must be compressible, i.e. it has no definite volume. This is a property of gases.

Question 18

Substances A and B are heated. The graph shows the temperature of A and B over time. [Graph: Substance A starts at 0 °C, rises, then plateaus at 60 °C; Substance B starts at 40 °C, plateaus, then rises to 100 °C and plateaus.] Which row correctly identifies the states of substances A and B at 20 °C and 120 °C? [Table options listing combinations of solid/liquid/gas/not possible to tell.]

Accepted Answer

B. 20°C: A liquid, B solid; 120°C: A gas, B gas. Substance A starts at 0 °C and melts at 60 °C — so at 20 °C it is liquid (already above its melting point of 0 °C). Substance B starts at 40 °C and melts at 40 °C, then boils at 100 °C — at 20 °C it is solid. At 120 °C, A (boiling point 60 °C) is gas and B (boiling point 100 °C) is gas.

Question 19

When a bulb was blown in the circuit, one other bulb did not light up. Which bulb was blown?

Accepted Answer

A. W. The bulb that, when blown, causes one other specific bulb to go out (because they are in series on the same branch) while leaving the rest of the circuit functional is W. Bulbs in the parallel branches continue to light, but the branch containing W is broken.

Question 20

The diagram shows a motorcyclist getting ready to stop at a traffic light that has turned red. Which statement explains why the motorcyclist is able to see the red light?

Accepted Answer

A. The traffic light gives out light.. A traffic light is a luminous object — it produces its own light. That light travels into the motorcyclist's eyes, allowing him to see it.

Question 21

The diagram shows four objects of the same height. The four objects are placed at different positions between a light source and a screen. Which of the following shows the shadows formed on the screen?

Accepted Answer

B. (2). Objects closer to the light source cast larger shadows on the screen, while objects further from the light (closer to the screen) cast smaller shadows of about their actual size. Option 2 correctly shows the small objects (those closer to the screen) appearing close to actual size, and objects further away appearing larger.

Question 22

An experiment of four identical beakers containing different amounts of water at different temperatures were placed on the hot plate and then heated up at the same time. Based on the experiment, which statement is false?

Accepted Answer

C. Beaker B has more heat than beaker D at the start of the experiment.. Beaker B (200 cm³ at 20 °C) has less water at the same temperature as Beaker D (500 cm³ at 20 °C). The beaker with more water at the same temperature contains more heat, so D actually has more heat than B. Statement C is therefore false.

Question 23

A spring was pulled to position A and then released. The spring moved from A to B and came to a stop at C. Which row describes the energy of the spring at A, B and C?

Accepted Answer

D. Kinetic: B; Elastic potential: A,B. At A the spring is stretched (elastic potential energy, no movement). At B it is moving (kinetic energy) and still partly stretched (elastic potential energy). At C it is compressed and stationary (elastic potential energy only). So kinetic = B; elastic potential = A and B (and C). The best matching option is D (kinetic at B; elastic potential at A and B).

Question 24

Michelle set up an experiment with four rods of the same size but made from different materials, W, X, Y and Z. She placed the same amount of wax on the tip of each rod and poured boiling water into the container. She measured and recorded the time taken for the wax on the rods to melt. Her results are plotted in the graph below. [Bar graph: Y takes the longest time, then W, then Z, then X (shortest).] Which material is the most suitable for making boxes to keep food warm for the longest time?

Accepted Answer

C. Y. The longest time for the wax to melt means the material is the poorest conductor of heat (best insulator). Y took the longest time, so it is the best insulator and most suitable for making boxes to keep food warm.

Question 25

Li Wen had two similar metal bars PQ and RS. She arranged the two bars in four different ways and the diagrams below show her observations. [Diagrams: (1) PQ horizontal, RS vertical hanging below from end of PQ near Q — weaker force; (2) RS vertical, with Q at the bottom (PQ attached to RS at end S) — stronger force; (3) P end of bar attracted from a distance to R end of RS — stronger force; (4) end P of bar Q-P attracted to a shaded end S of R-S bar — stronger force.] Which of the following best describes the two bars?

Accepted Answer

B. PQ magnet, RS magnetic material. The differences in attraction (stronger when one end of PQ is presented) show PQ has defined poles — a magnet. RS is attracted equally from any end, indicating it is a magnetic material (induced magnet). Therefore PQ is the magnet and RS is the magnetic material.

Question 26

Which of following is not an example of a force?

Accepted Answer

C. a roof blocking the sunlight. Bouncing a ball, inflating a balloon, and switching on a torch all involve a push or a pull (force). A roof blocking sunlight involves the absorption/blocking of light, not a force acting on the light.

Question 27

Two magnets, C and D, were placed close together with their North poles as shown. When D was released, it moved along the surface of the floor. Which row shows the direction of the magnetic force acting on C and the direction of frictional force acting on D?

Accepted Answer

B. Magnetic force on C: ←; Friction on D: ←. Like poles repel, so the magnetic force on C from D pushes C to the left (←). When D moves to the right (away from C), frictional force always opposes motion, so friction on D acts to the left (←).

Question 28

In which circuit would bulb P be the brightest?

Accepted Answer

D. (4). Bulb P is brightest when it receives the greatest share of voltage/current. In circuit 4, the single bulb P is in a parallel branch directly across the cell, so it receives the full battery voltage with the least resistance compared to the other circuits.

P6 Science SA2 2025 — Nan Hua

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