Question 1

A plant closes its leaves when touched. This shows that the plant is a living thing because it can ____.

Accepted Answer

B. respond. Closing leaves when touched is a reaction to a stimulus (touch), which is the characteristic of responding to changes in the surroundings.

Question 2

Which one of the following statements is true for ALL mammals?

Accepted Answer

D. They have hair as outer covering.. A defining characteristic of all mammals is that they have hair (or fur) as their outer body covering. Not all mammals have tails, live on land, or have wings.

Question 3

The diagram shows a plant. Which part, (1), (2), (3) or (4), obtains water for the plant?

Accepted Answer

D. Part (4) — roots. Roots absorb water and mineral salts from the soil for the plant.

Question 4

Which one of the following shows the correct order when food moves through some parts of the digestive system?

Accepted Answer

C. stomach → small intestine → large intestine. Food moves from the stomach to the small intestine (where nutrients are absorbed) and then to the large intestine (where water is absorbed).

Question 5

The diagram below shows the life cycle of an animal. Which animal is likely to have the life cycle as shown above?

Accepted Answer

C. butterfly. The life cycle shown has four stages: egg → larva → pupa → adult. This is complete metamorphosis, which a butterfly undergoes. A cockroach has no pupa stage.

Question 6

Which one of the following can be attracted by a magnet?

Accepted Answer

A. iron ball. Magnets attract magnetic materials such as iron. Paper, plastic and wood are non-magnetic.

Question 7

Which one of the following objects can be bent easily without breaking?

Accepted Answer

B. carpet. A carpet is flexible and can be bent or rolled easily without breaking. A metal ruler/spoon is hard to bend and a glass window is brittle.

Question 8

Which one of the following is a source of light?

Accepted Answer

D. flame. A flame produces its own light. An apple and a leaf only reflect light, and the moon reflects sunlight rather than producing its own light.

Question 9

Which one of the following is NOT a source of heat?

Accepted Answer

B. A sweater. A sweater does not produce heat; it only traps heat from the body. The Sun, a lighted bulb, and a candle flame all produce heat.

Question 10

Which one of the following substances has a definite shape?

Accepted Answer

B. door. Only solids have a definite shape. A door is a solid; oil and water are liquids and oxygen is a gas.

Question 11

The diagram below shows the life cycle of animal X. Which of the following characteristics of living things are shown in the life cycle of animal X in the diagram above? A. Living things can grow. B. Living things can reproduce. C. Living things need air, food and water. D. Living things respond to changes in the surroundings.

Accepted Answer

A. A and B only. A life cycle shows the animal growing from young to adult (grow) and producing more of its kind (reproduce). The diagram does not show the need for air/food/water nor a response to stimuli.

Question 12

Anu saw two plants, G and H, in the school garden. Which of the following statements about the two plants is/are correct? A. Both plants have flowers. B. Only plant G can make food. C. Leaves of both plants can make food using sunlight.

Accepted Answer

B. C only. Both plants have green leaves, so both can make food using sunlight through photosynthesis. Only plant G clearly shows flowers; plant H does not, so statement A is wrong. Statement B is wrong because plant H can also make food.

Question 13

Study the classification chart below. Group A contains hamster, sheep, dolphin. Group B contains fish, crocodile, bee. Which one of the following shows how the above animals have been grouped?

Accepted Answer

C. Group A: Give birth to young alive / Group B: Lay eggs. Hamster, sheep and dolphin are mammals that give birth to live young. Fish, crocodile and bee all lay eggs.

Question 14

Which of the following are common characteristics of fern and fungi? A. They do not bear flowers. B. They make their own food. C. They reproduce by spores. D. They get food from living things they grow on.

Accepted Answer

B. A and C only. Both ferns and fungi do not bear flowers and both reproduce by spores. Only ferns make their own food; fungi do not. Only fungi feed on other living/dead things.

Question 15

The diagram below shows parts, X, Y and Z, of a plant. Which one of the following shows the correct functions of plant parts, X, Y and Z?

Accepted Answer

B. X: Make food for plant / Y: Holds up the leaves / Z: Anchor plant firmly to ground. X is a leaf (makes food), Y is the stem (holds up leaves and transports water), and Z is the roots (anchor the plant firmly to the ground and absorb water).

Question 16

Which one of the following shows the incorrect function of the human systems?

Accepted Answer

C. Circulatory System — Removes undigested food from the body.. The circulatory system transports blood, oxygen and nutrients around the body; it does not remove undigested food. Removing undigested food is done by the digestive system.

Question 17

The diagram below represents the digestive system. Which one of the following graphs shows the correct amount of undigested food leaving each part of the digestive system?

Accepted Answer

C. Bars: A high, B equally high, C slightly lower, D lower, E none (zero). As food moves along the digestive tract, more of it gets digested or absorbed. By the end of the large intestine (E), undigested food has been passed out, so the amount leaving E should be zero/almost none, decreasing in steps along A→B→C→D→E.

Question 18

Which of the following correctly represents the life cycle of a mosquito?

Accepted Answer

B. egg → larva → pupa → mosquito → egg. A mosquito undergoes complete metamorphosis: egg → larva → pupa → adult mosquito.

Question 19

The table below shows the number of days animal Z spends at each stage of its life cycle. Stages: Eggs 5 days, Adult 30 days, Pupa 10 days, Larva 15 days. How many days does it take for animal Z to first turn into an adult after the eggs were hatched?

Accepted Answer

A. 25. After eggs have hatched, the animal must complete the larva (15 days) and pupa (10 days) stages before becoming an adult: 15 + 10 = 25 days.

Question 20

Sarah set up an experiment as shown below. Which of the following changes should she make in order to observe a larger shadow on the screen? A. Move the torch nearer to the object. B. Move the screen away from the object. C. Move the torch further away from the object. D. Move both the object and screen away from the torch by 5 cm.

Accepted Answer

B. A and B only. To make a larger shadow, you can move the light source closer to the object (A) or move the screen further from the object (B). Moving the torch further away (C) makes the shadow smaller; moving both object and screen the same distance from the torch keeps relative distances similar (D).

Question 21

Jackson set up an experiment as shown below. The torch was switched on and the sensor recorded the amount of light that passed through the material. He repeated the experiment using different materials and the results of his experiment are shown in the table below. Material A: 750, Material B: 600, Material C: 920, Material D: 230. Which material should Jackson use for his room curtains if he wanted to sleep in a darker room during the day?

Accepted Answer

D. D. The lower the light reading, the less light passes through. Material D has the lowest reading (230 units), so it blocks the most light and is most suitable for darkening the room.

Question 22

Jason heated a beaker of water until it reached 100 °C. The beaker of water was then immediately left on a table to cool to room temperature. Which one of the following graphs correctly shows the changes in the temperature of the substances in the beaker?

Accepted Answer

D. Temperature rises from room temperature to 100 °C then decreases back to room temperature. The water starts at room temperature, is heated up to 100 °C, then cools back down toward room temperature. The graph must show a rise to 100 °C followed by a gradual decrease to room temperature.

Question 23

May was unable to separate two bowls that were stuck to each other. Which of the following actions should May take to separate the two bowls? A. Pour hot water into bowl A. B. Add some ice cubes into bowl A. C. Wrap a towel that is soaked in ice water around bowl B. D. Wrap a towel that is soaked in hot water around bowl B.

Accepted Answer

C. B and C only. The inner bowl (A) should contract (cool with ice cubes) and the outer bowl (B) should expand (warm with hot water). The combination given as B and D is incorrect because warming bowl B and cooling bowl A together is needed; here the correct given combination is bowl A cooled and bowl B warmed. Among the options, only adding ice to bowl A (B) combined with hot water on bowl B (D) achieves this — option D 'B and D only' would actually be most correct. However, based on the provided choices the matched pair is option (4): B and D only.

Question 24

The diagram below shows 2 different objects, X and Y, being placed into a beaker filled with the same amount of water. After the objects were placed into the beakers of water, it was observed that the water level in both beakers were identical. Based on the set-ups above, which one of the following conclusions about objects X and Y is correct?

Accepted Answer

C. X and Y have the same volume.. When objects are placed in water, the rise in water level depends on the volume of the object. Since both beakers rise to the same level, the objects displace the same amount of water and therefore have the same volume.

Question 25

Ashton pushed the plunger into an empty container as shown below (200 cm³ of air). What would happen to the mass and volume of air inside the container after Ashton pushed the plunger in?

Accepted Answer

C. Mass remains the same / Volume decreases. Air is compressed when the plunger is pushed in, so its volume decreases. No air enters or leaves the sealed container, so the mass of air stays the same.

Question 26

Si Ling listed the properties of 4 materials, J, K, L and M, in the table below. Material J: tears easily No, waterproof Yes, flexible No. Material K: tears easily No, waterproof Yes, flexible Yes. Material L: tears easily Yes, waterproof Yes, flexible Yes. Material M: tears easily No, waterproof No, flexible Yes. Which one of the materials is most suitable for making a swimming cap?

Accepted Answer

B. Material K. A swimming cap must be waterproof, flexible (to fit on the head) and not tear easily. Material K is waterproof, flexible and does not tear easily.

Question 27

Five bar magnets with their ends marked from A to J can be arranged as shown below without any repulsion. Which one of the following diagrams shows a possible arrangement of two of the above magnets?

Accepted Answer

D. Magnet with ends E-F placed end-to-end horizontally with magnet J-I. Since the original arrangement shows no repulsion, the touching poles in each pair must be opposite. By tracking the polarities in the original chain, F and J are opposite poles when E-F is paired with J-I, so they attract.

Question 28

The diagram below shows a beam balance with objects S and T hung at both ends. Both objects are of the same mass. The diagram below shows what happens when an object, X, is placed below object S. Based on the observations above, which one of the following best describes objects S and X?

Accepted Answer

A. S: Magnet / X: Steel block. S tilts downward toward X, showing that X attracts S. If S is a magnet and X is a steel block, the magnet attracts the steel below and is pulled downward. (B) is also possible if poles attract; (A) is the simpler, certain answer.

P4 Science SA2 2020 — Nanyang

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