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Primary 4 Science Semestral Assessment 2 (End of Year) Paper 2

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Questions

TuitionGoWhere Practice Paper - Science Primary 4

TuitionGoWhere Exam Practice (AI)

Subject: Science
Level: Primary 4
Paper: SA2 (Version 2)
Duration: 1 h 45 min
Total Marks: 100

Name: ___________________________
Class: Primary 4 _______
Date: _______________

INSTRUCTIONS TO CANDIDATES

Do not open this booklet until you are told to do so.
Follow all instructions carefully.
Answer all questions.
For Section A, shade your answers on the Optical Answer Sheet (OAS) provided.
For Section B, write your answers in the spaces provided in this booklet.
The number of marks is given in brackets [ ] at the end of each question or part question.
The total marks for this paper is 100.

SECTION A (56 marks)

For each question from 1 to 28, four options are given. One of them is the correct answer. Make your choice (1, 2, 3 or 4) and shade the correct oval on the OAS. Each question carries 2 marks.

Question 1

Which of the following is a non-living thing?

(1) Mushroom
(2) Moss
(3) Pebble
(4) Fern

[2]

Question 2

Study the classification chart below.

<image_placeholder> id: Q2-fig1 type: diagram linked_question: Q2 description: Classification chart with two main groups: Living Things and Non-Living Things. Living Things branch into Plants and Animals. Plants branch into Flowering and Non-Flowering. Animals branch into Insects, Birds, Fish, Mammals, Reptiles, Amphibians. Non-Living Things branch into Man-Made and Natural. Three items X, Y, Z are placed as: X under Flowering Plants, Y under Insects, Z under Man-Made Non-Living Things. labels: X, Y, Z values: None must_show: Clear hierarchy with branches and three items placed at different endpoints </image_placeholder>

Which of the following correctly identifies X, Y and Z?

	X	Y	Z
(1)	Rose plant	Butterfly	Plastic bottle
(2)	Pine tree	Spider	Wooden chair
(3)	Mushroom	Earthworm	Metal spoon
(4)	Fern	Grasshopper	Cotton shirt

[2]

Question 3

Which of the following groups of animals are all insects?

(1) Ant, spider, beetle
(2) Butterfly, grasshopper, mosquito
(3) Cockroach, centipede, fly
(4) Bee, scorpion, dragonfly

[2]

Question 4

Study the flowchart below.

<image_placeholder> id: Q4-fig1 type: diagram linked_question: Q4 description: Flowchart for classifying animals. Start: Does it have 6 legs? Yes -> Does it have wings? Yes -> Insect (e.g. Butterfly). No -> Insect (e.g. Ant). No (from 6 legs) -> Does it have 8 legs? Yes -> Arachnid (e.g. Spider). No -> Does it have backbone? Yes -> Vertebrate. No -> Other invertebrate. labels: Decision boxes, outcome boxes values: None must_show: Clear decision diamond shapes with Yes/No branches, final classification boxes with examples </image_placeholder>

Animal P has 8 legs and no wings. Animal Q has a backbone and 4 legs. Which groups do Animal P and Animal Q belong to?

	Animal P	Animal Q
(1)	Arachnid	Mammal
(2)	Insect	Bird
(3)	Arachnid	Vertebrate
(4)	Insect	Vertebrate

[2]

Question 5

Which of the following statements about fungi is correct?

(1) Fungi make their own food.
(2) Fungi reproduce by seeds.
(3) Fungi are non-living things.
(4) Fungi reproduce by spores.

[2]

Question 6

Study the diagram below.

<image_placeholder> id: Q6-fig1 type: diagram linked_question: Q6 description: Cross-section of a flower showing parts labelled A, B, C, D. A: Stigma (top of pistil), B: Anther (top of stamen), C: Ovary (base of pistil), D: Petal. labels: A, B, C, D values: None must_show: Clear flower cross-section with four labelled parts: stigma, anther, ovary, petal </image_placeholder>

Which part produces pollen grains?

(1) A
(2) B
(3) C
(4) D

[2]

Question 7

The table below shows the characteristics of four plants, W, X, Y and Z. A tick (✓) shows the plant has the characteristic.

Plant	Bears flowers	Bears fruits	Reproduces by spores	Grows on land
W	✓	✓		✓
X			✓	✓
Y	✓	✓
Z			✓

Which plant is most likely a water plant that reproduces by spores?

(1) W
(2) X
(3) Y
(4) Z

[2]

Question 8

Which of the following shows the correct order of stages in the life cycle of a butterfly?

(1) Egg → Pupa → Larva → Adult
(2) Egg → Larva → Pupa → Adult
(3) Egg → Nymph → Adult
(4) Egg → Adult → Larva → Pupa

[2]

Question 9

The diagram below shows the life cycle of a mosquito.

<image_placeholder> id: Q9-fig1 type: diagram linked_question: Q9 description: Life cycle diagram of mosquito with four stages in a cycle: Egg → Larva → Pupa → Adult. Arrows show direction. Labels: Stage A (Egg), Stage B (Larva), Stage C (Pupa), Stage D (Adult). Stage B and C are marked as 'aquatic'. labels: Stage A, Stage B, Stage C, Stage D values: None must_show: Four-stage cycle with aquatic labels on larva and pupa, arrows showing progression </image_placeholder>

At which stage(s) does the mosquito live in water?

(1) Stage A only
(2) Stage B only
(3) Stage B and Stage C only
(4) Stage A, Stage B and Stage C

[2]

Question 10

Mei Ling observed a young grasshopper (nymph) and an adult grasshopper. Which of the following statements is true?

(1) The nymph has wings but the adult does not.
(2) The nymph and the adult have the same number of legs.
(3) The nymph looks exactly like the adult, only smaller.
(4) The nymph undergoes complete metamorphosis.

[2]

Question 11

Which of the following materials is a good conductor of heat?

(1) Wood
(2) Plastic
(3) Metal
(4) Rubber

[2]

Question 12

Study the set-up below.

<image_placeholder> id: Q12-fig1 type: experimental_setup linked_question: Q12 description: Three identical rods made of copper, wood, and plastic are fixed side by side. One end of each rod is dipped in hot water (80°C). A thumbtack is attached to the other end of each rod using wax. Initial temperature of rods: 30°C. labels: Copper rod, Wooden rod, Plastic rod, Hot water, Thumbtack, Wax values: Hot water = 80°C, Initial rod temp = 30°C must_show: Three parallel rods with one end in hot water, thumbtacks at far ends attached with wax, labels for each material </image_placeholder>

The thumbtack on the copper rod dropped first. This shows that copper is a __________.

(1) poor conductor of heat
(2) good conductor of heat
(3) poor insulator of heat
(4) good insulator of heat

[2]

Question 13

Which of the following shows the correct state of water at the given temperature?

	Temperature	State of water
(1)	0°C	Gas
(2)	25°C	Liquid
(3)	100°C	Solid
(4)	-5°C	Liquid

[2]

Question 14

Ice cubes were placed in a beaker and heated. The temperature was recorded every minute. The graph below shows the results.

<image_placeholder> id: Q14-fig1 type: graph linked_question: Q14 description: Temperature vs Time graph. X-axis: Time (min), 0 to 20. Y-axis: Temperature (°C), 0 to 100. Graph shows: flat line at 0°C from 0-5 min (melting), rising line from 5-15 min (heating water), flat line at 100°C from 15-20 min (boiling). labels: Time (min), Temperature (°C), Melting, Heating, Boiling values: Melting at 0°C for 5 min, Boiling at 100°C for 5 min must_show: Clear plateau at 0°C and 100°C, rising slope between, labelled axes with units </image_placeholder>

During which period was the water boiling?

(1) 0 to 5 minutes
(2) 5 to 15 minutes
(3) 15 to 20 minutes
(4) 0 to 20 minutes

[2]

Question 15

A metal ball fits tightly through a metal ring at room temperature. When the metal ball is heated, it cannot pass through the ring. When the metal ring is heated, the ball can pass through easily. This shows that:

(1) Metal expands when heated and contracts when cooled.
(2) Metal contracts when heated and expands when cooled.
(3) Only the metal ball expands when heated.
(4) Only the metal ring expands when heated.

[2]

Question 16

Which of the following is a source of light?

(1) Moon
(2) Mirror
(3) Sun
(4) Book

[2]

Question 17

Study the diagram below.

<image_placeholder> id: Q17-fig1 type: diagram linked_question: Q17 description: A torch shining on an opaque wooden block. A screen is placed behind the block. A sharp shadow is formed on the screen. Labels: Torch (light source), Wooden block (opaque object), Screen, Shadow. labels: Torch, Wooden block, Screen, Shadow values: None must_show: Light rays from torch blocked by block, sharp shadow on screen, straight light ray lines </image_placeholder>

A sharp shadow is formed on the screen because __________.

(1) light bends around the wooden block
(2) light passes through the wooden block
(3) light travels in straight lines and is blocked by the wooden block
(4) the wooden block reflects light to the screen

[2]

Question 18

Ahmed placed a pencil in a beaker of water. The pencil appeared bent at the water surface. This is because __________.

(1) light travels in straight lines in water
(2) light is reflected by the water
(3) light changes direction when it passes from air into water
(4) the pencil is actually bent

[2]

Question 19

Which of the following objects will not cast a shadow when light shines on it?

(1) A clear glass cup
(2) A wooden ruler
(3) A metal spoon
(4) A ceramic mug

[2]

Question 20

Study the circuit diagram below.

<image_placeholder> id: Q20-fig1 type: diagram linked_question: Q20 description: Simple series circuit: Battery (2 cells) → Switch (closed) → Bulb → Wire back to battery. All components connected in a single loop. labels: Battery, Switch, Bulb, Wires values: 2 cells in battery must_show: Complete closed loop with standard circuit symbols </image_placeholder>

What will happen to the bulb when the switch is open?

(1) The bulb will light up brightly.
(2) The bulb will light up dimly.
(4) The bulb will not light up.
(4) The bulb will flicker.

[2]

Question 21

Which of the following circuits has the bulbs arranged in parallel?

<image_placeholder> id: Q21-fig1 type: diagram linked_question: Q21 description: Four circuit diagrams labelled (1) to (4). (1) Series: Battery - Bulb - Bulb - Battery. (2) Parallel: Battery splits to two branches each with a bulb, joins back. (3) Series with switch. (4) Short circuit. labels: Circuit (1), Circuit (2), Circuit (3), Circuit (4) values: None must_show: Clear standard circuit symbols, distinct series vs parallel arrangements </image_placeholder>

(1) Circuit (1)
(2) Circuit (2)
(3) Circuit (3)
(4) Circuit (4)

[2]

Question 22

In a series circuit with two identical bulbs and one battery, one bulb is removed. What happens to the other bulb?

(1) It lights up more brightly.
(2) It lights up with the same brightness.
(3) It does not light up.
(4) It becomes dimmer.

[2]

Question 23

Which of the following materials is magnetic?

(1) Copper coin
(2) Aluminium foil
(3) Steel nail
(4) Plastic ruler

[2]

Question 24

Study the diagram below.

<image_placeholder> id: Q24-fig1 type: diagram linked_question: Q24 description: Bar magnet with North (N) and South (S) poles labelled. Iron nail placed near the North pole. Arrow shows nail being attracted to the magnet. labels: N pole, S pole, Iron nail values: None must_show: Bar magnet with clear N/S labels, iron nail near N pole, attraction arrow </image_placeholder>

The iron nail is attracted to the magnet because __________.

(1) the iron nail is a magnet
(2) the iron nail becomes a temporary magnet
(3) the iron nail is made of copper
(4) the magnet repels the iron nail

[2]

Question 25

Two magnets are placed near each other as shown.

<image_placeholder> id: Q25-fig1 type: diagram linked_question: Q25 description: Two bar magnets placed end to end. Left magnet: N on left, S on right. Right magnet: N on left, S on right. The facing poles are S (left magnet) and N (right magnet). Double-headed arrow between them labelled 'Attraction'. labels: N, S poles on both magnets values: None must_show: Clear N/S labels, facing opposite poles, attraction arrow </image_placeholder>

What will happen if the right magnet is flipped so that its South pole faces the South pole of the left magnet?

(1) They will attract.
(2) They will repel.
(3) Nothing will happen.
(4) They will stick together.

[2]

Question 26

Which of the following forces is a pull?

(1) Pushing a trolley
(2) Kicking a ball
(3) Gravity acting on an apple
(4) Pressing a doorbell

[2]

Question 27

A toy car is released from the top of a ramp. It moves down the ramp and stops on the flat floor. Which force causes the car to stop?

(1) Gravity
(2) Friction
(3) Magnetism
(4) Elastic spring force

[2]

Question 28

Study the diagram below.

<image_placeholder> id: Q28-fig1 type: diagram linked_question: Q28 description: A spring balance pulling a wooden block across three surfaces: (A) Sandpaper, (B) Wooden table, (C) Ice. Force readings shown: A = 8 N, B = 5 N, C = 1 N. labels: Surface A (Sandpaper), Surface B (Wood), Surface C (Ice), Force readings values: A = 8 N, B = 5 N, C = 1 N must_show: Spring balance pulling block on three surfaces with different force readings </image_placeholder>

On which surface is the friction between the block and the surface the greatest?

(1) Surface A
(2) Surface B
(3) Surface C
(4) Cannot be determined

[2]

SECTION B (44 marks)

Write your answers in the spaces provided. The number of marks is given in brackets [ ] at the end of each question or part question.

Question 29

The diagram below shows a plant.

<image_placeholder> id: Q29-fig1 type: diagram linked_question: Q29 description: Whole plant diagram with roots, stem, leaves, flowers, fruits. Labels: Part A (Roots), Part B (Stem), Part C (Leaf), Part D (Flower), Part E (Fruit). labels: A, B, C, D, E values: None must_show: Complete plant with five labelled parts: roots, stem, leaf, flower, fruit </image_placeholder>

(a) Name Part A and state its function. [1]

(b) Name Part C and state its function. [1]

Question 30

The diagram below shows the human digestive system.

<image_placeholder> id: Q30-fig1 type: diagram linked_question: Q30 description: Human digestive system with labels: A (Mouth), B (Gullet/Oesophagus), C (Stomach), D (Small Intestine), E (Large Intestine), F (Anus). Accessory organs: Liver, Pancreas shown but not labelled. labels: A, B, C, D, E, F values: None must_show: Complete digestive tract with six labelled parts, accessory organs visible </image_placeholder>

(a) In which part (A, B, C, D, E or F) is food completely digested and absorbed into the blood? [1]

(b) State the function of Part C. [1]

(d) Digestion begins in Part A. Name the digestive juice in Part A that starts digestion. [1]

Question 31

The table below shows the properties of four materials, P, Q, R and S. A tick (✓) shows the material has the property.

Material	Flexible	Waterproof	Transparent	Magnetic	Conducts electricity
P	✓	✓
Q		✓	✓
R		✓		✓	✓
S	✓

(a) Which material is most suitable for making a raincoat? Give a reason for your answer. [2]

(b) Which material is most suitable for making the core of an electromagnet? Give a reason for your answer. [2]

Question 32

John set up an experiment as shown below. He placed a metal spoon, a wooden chopstick, and a plastic ruler in a container of hot water at 90°C. He left them for 5 minutes.

<image_placeholder> id: Q32-fig1 type: experimental_setup linked_question: Q32 description: Three objects (metal spoon, wooden chopstick, plastic ruler) placed vertically in a beaker of hot water. Handles stick out. Thermometer in water reads 90°C. Timer shows 5 min. labels: Metal spoon, Wooden chopstick, Plastic ruler, Hot water (90°C), Thermometer values: Water temperature = 90°C, Time = 5 minutes must_show: Three objects in hot water, clear labels, thermometer reading </image_placeholder>

(a) After 5 minutes, which object will feel the hottest to touch? [1]

(b) Explain your answer in (a). [2]

Question 33

The diagram below shows the water cycle.

<image_placeholder> id: Q33-fig1 type: diagram linked_question: Q33 description: Water cycle diagram: Sun, evaporation from sea, condensation forming clouds, precipitation (rain), collection in rivers/sea. Labels: Process A (Evaporation), Process B (Condensation), Process C (Precipitation), Process D (Collection). labels: Process A, Process B, Process C, Process D values: None must_show: Complete water cycle with four labelled processes, sun, sea, clouds, rain, rivers </image_placeholder>

(a) Name Process A and Process B. [2]

Process A: ________________________________________________________________________

Process B: ________________________________________________________________________

(b) State the change in state of water during Process A. [1]

Question 34

A beaker contains 200 cm³ of water at 30°C. Ice cubes at 0°C are added and the mixture is stirred until all the ice melts. The final temperature of the water is 15°C.

(a) State the change in temperature of the original water. [1]

(b) Where did the heat from the original water go? [1]

Question 35

The diagram below shows a torch shining on a ball. A shadow is formed on the screen.

<image_placeholder> id: Q35-fig1 type: diagram linked_question: Q35 description: Torch on left, ball in middle, screen on right. Shadow on screen. Distance from torch to ball = 20 cm. Distance from ball to screen = 30 cm. Shadow height = 15 cm. Ball height = 10 cm. labels: Torch, Ball, Screen, Shadow values: Torch-to-ball = 20 cm, Ball-to-screen = 30 cm, Ball height = 10 cm, Shadow height = 15 cm must_show: Scale diagram with distances and heights labelled, light rays from torch past ball to screen </image_placeholder>

(a) The shadow formed is larger than the ball. Explain why. [2]

(b) If the ball is moved closer to the screen, what will happen to the size of the shadow? [1]

Question 36

The diagram below shows a simple circuit.

<image_placeholder> id: Q36-fig1 type: diagram linked_question: Q36 description: Series circuit: Battery (3 cells) → Switch → Bulb X → Bulb Y → Wire back to battery. Ammeter placed in series. Voltmeter across Bulb X. labels: Battery (3 cells), Switch, Bulb X, Bulb Y, Ammeter, Voltmeter values: 3 cells must_show: Complete series circuit with ammeter in series, voltmeter parallel to Bulb X </image_placeholder>

(a) Both bulbs light up when the switch is closed. Are the bulbs arranged in series or parallel? [1]

(b) If Bulb X fuses (blows), what will happen to Bulb Y? Explain. [2]

Question 37

Siti wants to find out how the number of batteries affects the brightness of a bulb in a series circuit. She sets up three circuits as shown.

<image_placeholder> id: Q37-fig1 type: diagram linked_question: Q37 description: Three circuits: Circuit 1: 1 battery + 1 bulb. Circuit 2: 2 batteries + 1 bulb. Circuit 3: 3 batteries + 1 bulb. All series. Brightness observed. labels: Circuit 1, Circuit 2, Circuit 3 values: 1, 2, 3 batteries respectively must_show: Three separate series circuits with increasing number of cells, one bulb each </image_placeholder>

(a) In which circuit will the bulb be the brightest? [1]

(b) State the relationship between the number of batteries and the brightness of the bulb. [1]

(c) Siti replaces the bulb in Circuit 3 with a buzzer. The buzzer makes a louder sound than in Circuit 1. What does this tell you about the energy conversion? [2]

Question 38

The diagram below shows a magnet being used to separate a mixture of iron nails and aluminium rivets.

<image_placeholder> id: Q38-fig1 type: experimental_setup linked_question: Q38 description: Magnet lowered into a tray containing mixed iron nails (grey) and aluminium rivets (silver). Iron nails are attracted to the magnet. Aluminium rivets remain in the tray. labels: Magnet, Iron nails, Aluminium rivets, Tray values: None must_show: Magnet attracting only iron nails, aluminium rivets left behind </image_placeholder>

(a) Explain why the iron nails are attracted to the magnet but the aluminium rivets are not. [2]

(b) Siti strokes an iron nail with a magnet 50 times in the same direction. The nail becomes a magnet. What is this method of making a magnet called? [1]

Question 39

A block of mass 2 kg is pulled across a horizontal table by a force of 10 N. The friction between the block and the table is 3 N.

(a) Draw and label the forces acting on the block in the diagram below. [2]

<image_placeholder> id: Q39-fig1 type: diagram linked_question: Q39 description: Rectangle representing block on horizontal surface. Four arrows to be drawn: Applied force (10 N) to the right, Friction (3 N) to the left, Weight (down), Normal reaction (up). labels: Applied force, Friction, Weight, Normal reaction values: Applied = 10 N, Friction = 3 N, Mass = 2 kg must_show: Block with four labelled force arrows in correct directions and relative lengths </image_placeholder>

(b) Calculate the net force acting on the block. [1]

Question 40

The diagram below shows a spring being stretched by hanging a 200 g mass on it.

<image_placeholder> id: Q40-fig1 type: diagram linked_question: Q40 description: Spring hanging from support. Original length 10 cm (no mass). With 200 g mass, length stretches to 14 cm. Mass labelled 200 g. Arrow shows extension. labels: Original length, Stretched length, Mass, Extension values: Original length = 10 cm, Stretched length = 14 cm, Mass = 200 g must_show: Spring before and after with lengths labelled, mass hanging, extension arrow </image_placeholder>

(a) What is the extension of the spring? [1]

(b) If a 400 g mass is hung on the same spring, what will be the new length of the spring? Assume the spring does not exceed its elastic limit. [2]

END OF PAPER

Answers

TuitionGoWhere Practice Paper - Science Primary 4 (SA2 Version 2) - Answer Key

Subject: Science
Level: Primary 4
Paper: SA2 (Version 2)
Total Marks: 100

SECTION A (56 marks)

Question 1

Answer: (3) Pebble
Marks: 2

Explanation: Living things need air, food, and water; they grow, reproduce, and respond to changes. Mushroom (fungus), moss (non-flowering plant), and fern (non-flowering plant) are all living things. A pebble is a non-living thing — it does not grow, reproduce, or need food/water/air.

Question 2

Answer: (1) X: Rose plant, Y: Butterfly, Z: Plastic bottle
Marks: 2

Explanation:

X is under Flowering Plants → Rose plant is a flowering plant. Pine tree is non-flowering (gymnosperm). Mushroom is a fungus (not a plant). Fern is a non-flowering plant.
Y is under Insects → Butterfly is an insect (6 legs, 3 body parts). Spider is an arachnid (8 legs). Earthworm is an annelid. Grasshopper is an insect but X would be wrong.
Z is under Man-Made Non-Living Things → Plastic bottle is man-made. Wooden chair is man-made but Y is wrong. Metal spoon is man-made but X,Y wrong. Cotton shirt is man-made but X,Y wrong.
Only option (1) fits all three positions correctly.

Question 3

Answer: (2) Butterfly, grasshopper, mosquito
Marks: 2

Explanation: Insects have 6 legs, 3 body parts (head, thorax, abdomen), and usually 2 pairs of wings as adults.

(1) Spider is an arachnid (8 legs).
(2) All three are insects. ✓
(3) Centipede is a myriapod (many legs).
(4) Scorpion is an arachnid (8 legs).

Question 4

Answer: (3) Animal P: Arachnid, Animal Q: Vertebrate
Marks: 2

Explanation:

Animal P has 8 legs → follows "No" to 6 legs, then "Yes" to 8 legs → Arachnid (e.g. Spider).
Animal Q has a backbone → follows "No" to 6 legs, "No" to 8 legs, "Yes" to backbone → Vertebrate.
Option (3) matches. Note: "Mammal" is a subgroup of vertebrates; the flowchart only identifies "Vertebrate" at that level.

Question 5

Answer: (4) Fungi reproduce by spores.
Marks: 2

Explanation:

(1) Fungi cannot make their own food; they are decomposers (saprotrophs) that absorb nutrients from dead/decaying matter.
(2) Fungi reproduce by spores, not seeds. Seeds are produced by flowering plants and gymnosperms.
(3) Fungi are living things (they grow, reproduce, respire).
(4) Correct — fungi (mould, yeast, mushrooms) reproduce by releasing spores.

Question 6

Answer: (2) B
Marks: 2

Explanation:

A = Stigma (receives pollen)
B = Anther (produces and contains pollen grains) ✓
C = Ovary (contains ovules, develops into fruit)
D = Petal (attracts pollinators)
The anther is the male reproductive part that produces pollen.

Question 7

Answer: (4) Z
Marks: 2

Explanation:

Water plant → does not grow on land (no tick for "Grows on land")
Reproduces by spores → tick for "Reproduces by spores"
Plant Z: No flowers, no fruits, reproduces by spores, does not grow on land → fits water plant (e.g. water fern) that reproduces by spores.
W: Land flowering plant. X: Land non-flowering (spores). Y: Water flowering plant (no "grows on land" but has flowers/fruits).

Question 8

Answer: (2) Egg → Larva → Pupa → Adult
Marks: 2

Explanation: Butterfly undergoes complete metamorphosis with four distinct stages:

Egg
Larva (caterpillar) — feeding stage
Pupa (chrysalis) — transformation stage
Adult (butterfly) — reproductive stage
Option (1) has wrong order. Option (3) is incomplete metamorphosis (grasshopper). Option (4) is illogical.

Question 9

Answer: (3) Stage B and Stage C only
Marks: 2

Explanation: Mosquito life cycle: Egg (laid on water surface) → Larva (aquatic, "wriggler") → Pupa (aquatic, "tumbler") → Adult (flies away).

Stage A (Egg) is on water surface, not "in water" living actively.
Stage B (Larva) and Stage C (Pupa) live in water (aquatic stages).
Stage D (Adult) is terrestrial/flying.

Question 10

Answer: (2) The nymph and the adult have the same number of legs.
Marks: 2

Explanation: Grasshopper undergoes incomplete metamorphosis: Egg → Nymph → Adult.

Nymphs resemble adults but are smaller, lack wings, and have underdeveloped reproductive organs.
Both nymph and adult have 6 legs (insect characteristic).
(1) False: Nymph has no wings; adult has wings.
(3) False: Nymph lacks wings, different proportions.
(4) False: Grasshopper has incomplete metamorphosis (no pupal stage).

Question 11

Answer: (3) Metal
Marks: 2

Explanation: Metals are good conductors of heat (and electricity). Wood, plastic, and rubber are poor conductors (good insulators) of heat.

Question 12

Answer: (2) good conductor of heat
Marks: 2

Explanation: The thumbtack on the copper rod dropped first because heat traveled fastest through the copper rod, melting the wax first. This shows copper conducts heat well → good conductor of heat.
Note: "Poor insulator" (3) is technically true but "good conductor" (2) is the direct, standard description for metals in primary science.

Question 13

Answer: (2) 25°C → Liquid
Marks: 2

Explanation:

(1) 0°C → Freezing/melting point; water is solid (ice) or liquid, not gas.
(2) 25°C → Room temperature; water is liquid. ✓
(3) 100°C → Boiling point; water is gas (steam) or liquid, not solid.
(4) -5°C → Below freezing; water is solid (ice).

Question 14

Answer: (3) 15 to 20 minutes
Marks: 2

Explanation: The graph shows:

0–5 min: Temperature constant at 0°C → Melting (solid to liquid)
5–15 min: Temperature rises from 0°C to 100°C → Heating liquid water
15–20 min: Temperature constant at 100

<stage3_exam_answers_md>

TuitionGoWhere Practice Paper - Science Primary 4 (SA2 Version 2) - Answer Key

Subject: Science
Level: Primary 4
Paper: SA2 (Version 2)
Total Marks: 100

SECTION A (56 marks)

Question	Answer	Explanation
1	(3) Pebble	Mushroom, moss, and fern are living things (fungi/plants). Pebble is a non-living thing.
2	(1) Rose plant, Butterfly, Plastic bottle	X is under Flowering Plants → Rose plant. Y is under Insects → Butterfly. Z is under Man-Made Non-Living Things → Plastic bottle.
3	(2) Butterfly, grasshopper, mosquito	All three are insects (6 legs, 3 body parts). Spider (arachnid), centipede (myriapod), scorpion (arachnid) are not insects.
4	(3) Arachnid, Vertebrate	Animal P has 8 legs → Arachnid. Animal Q has a backbone → Vertebrate.
5	(4) Fungi reproduce by spores	Fungi are living things, do not make their own food (decomposers), and reproduce by spores, not seeds.
6	(2) B	Part B is the anther, which produces pollen grains.
7	(4) Z	Water plant = does not grow on land (no tick). Reproduces by spores = tick in spore column. Only Z fits.
8	(2) Egg → Larva → Pupa → Adult	Butterfly undergoes complete metamorphosis: egg, larva (caterpillar), pupa (chrysalis), adult.
9	(3) Stage B and Stage C only	Mosquito larva and pupa are aquatic stages. Egg is laid on water surface but not "living in water" in the same way. Adult is terrestrial/flying.
10	(2) The nymph and the adult have the same number of legs	Grasshoppers undergo incomplete metamorphosis. Nymphs resemble adults but lack wings. Both have 6 legs.
11	(3) Metal	Metals are good conductors of heat. Wood, plastic, rubber are poor conductors (insulators).
12	(2) good conductor of heat	Thumbtack dropped first on copper rod → heat traveled fastest through copper → copper is a good conductor of heat.
13	(2) 25°C, Liquid	Water is liquid at room temperature (25°C). At 0°C it freezes (solid), at 100°C it boils (gas), at -5°C it is solid (ice).
14	(3) 15 to 20 minutes	Graph shows plateau at 100°C from 15-20 min → boiling (change of state from liquid to gas at constant temperature).
15	(1) Metal expands when heated and contracts when cooled	Heated ball expands (cannot pass through ring). Heated ring expands (hole gets larger, ball passes through).
16	(3) Sun	Sun produces its own light. Moon reflects sunlight. Mirror reflects light. Book reflects light.
17	(3) light travels in straight lines and is blocked by the wooden block	Shadows form because light travels in straight lines and opaque objects block light.
18	(3) light changes direction when it passes from air into water	Refraction: light bends when passing between media of different optical densities (air to water).
19	(1) A clear glass cup	Transparent objects allow most light to pass through, so they do not cast a distinct shadow. Opaque objects (wood, metal, ceramic) cast shadows.
20	(3) The bulb will not light up	Open switch breaks the circuit → incomplete circuit → no current flows → bulb does not light.
21	(2) Circuit (2)	Circuit (2) shows parallel arrangement: current splits across two branches each with a bulb.
22	(3) It does not light up	Series circuit: removing one bulb breaks the single path → open circuit → no current → other bulb goes out.
23	(3) Steel nail	Steel contains iron, which is magnetic. Copper, aluminium, plastic are non-magnetic.
24	(2) the iron nail becomes a temporary magnet	Magnetic induction: the magnet's field induces temporary magnetism in the iron nail, causing attraction.
25	(2) They will repel	Like poles (S-S) repel. Opposite poles (S-N) attract.
26	(3) Gravity acting on an apple	Gravity pulls objects toward Earth's centre. Pushing, kicking, pressing are push forces.
27	(2) Friction	Friction between wheels/floor opposes motion, causing the car to stop. Gravity pulls it down the ramp.
28	(1) Surface A	Greatest force needed (8 N) to pull block → greatest friction. Sandpaper is roughest surface.

SECTION B (44 marks)

Question 29

(a) Part A: Roots
Function: Absorb water and mineral salts from the soil / Anchor the plant firmly to the ground. [1]

(b) Part C: Leaf
Function: Make food for the plant through photosynthesis / Gaseous exchange. [1]

(c) Part C (leaves) will turn yellow / wither / die.
Explanation: Without light, the plant cannot photosynthesise to make food. The chlorophyll breaks down, causing leaves to turn yellow and eventually die. [2]

Question 30

(a) Part D (Small Intestine) [1]

(b) Function of Part C (Stomach): Churns food and mixes it with digestive juices / Begins digestion of proteins / Kills bacteria in food. [1]

(c) Water is absorbed from the undigested food. The remaining undigested food is passed out of the body as faeces through Part F (Anus). [1]

Question 31

The diagram shows the life cycle of a mealworm beetle (or darkling beetle).

(a) Stage X: Pupa [1]

(b) The mealworm beetle undergoes complete metamorphosis. [1]

(c) Difference: The larva (mealworm) looks very different from the adult (beetle) — it has no wings, no hard wing covers, and a worm-like body. The nymph of a grasshopper resembles the adult but is smaller and lacks wings. [2]

Question 32

(a) Process A: Melting
Process B: Boiling / Evaporation [2]

(b) At 0°C: Solid and Liquid (ice and water coexist during melting).
At 100°C: Liquid and Gas (water and steam coexist during boiling). [2]

(c) The temperature remains constant during a change of state because heat energy is used to overcome forces of attraction between particles, not to increase kinetic energy. [1]

Question 33

(a) Material: Metal / Copper / Aluminium (any good conductor of heat) [1]

(b) Reason: Metal is a good conductor of heat. It conducts heat away from the food quickly, cooling it faster. [1]

(c) Wood / Plastic / Rubber / Ceramic (any poor conductor/insulator) [1]

Question 34

(a) Light travels in straight lines. [1]

(b) A shadow is formed on the screen because the opaque cardboard blocks the light from the torch. [1]

(c) The shadow will become larger / bigger.
Reason: When the object is moved closer to the light source, it blocks more light rays, forming a larger shadow on the screen. [2]

Question 35

(a) Bulb arrangement: Parallel [1]

(b) The other bulbs will continue to light up with the same brightness. [1]

(c) Advantage: If one bulb fuses/blows, the other bulbs will still light up. / Each bulb can be controlled independently with its own switch. / All bulbs receive the full voltage of the battery and shine at maximum brightness. (Any one) [1]

Question 36

(a) Repel [1]

(b) Like poles face each other (North-North or South-South). [1]

(c) Method: Stroke the steel rod with a magnet in one direction repeatedly (stroking method). / Place the steel rod inside a solenoid and pass direct current through it (electrical method). (Any one) [1]

Question 37

(a) Force: Friction [1]

(b) The frictional force between the tyres and the road opposes the motion of the bicycle, causing it to slow down and stop. [1]

(c) Two ways:

Apply lubricant (oil/grease) to the axles/chain to reduce friction.
Use smoother tyres / Pump tyres to correct pressure / Use ball bearings in wheels. (Any two) [2]

Question 38

(a) Gravitational force acting on the ball: Weight / Gravity [1]

(b) The stretched elastic band exerts an elastic spring force on the ball, pushing it upward/forward. [1]

(c) Use a thicker / stronger elastic band. / Stretch the elastic band more before releasing. / Use a lighter ball. (Any one) [1]

END OF ANSWER KEY