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Primary 5 Science Semestral Assessment 2 (End of Year) Paper 2
Free P5 Science SA2 Paper 2, Nemo3 Exam version, with questions, answers, and syllabus-aligned practice for Singapore students.
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TuitionGoWhere Practice Paper - Science Primary 5 (SA2 Version 2) - Answer Key
Subject: Science
Level: Primary 5
Paper: SA2 (Version 2)
Total Marks: 100
SECTION A (56 marks)
1. (3) A, B and C only [2]
Explanation:
- A is correct: The anther is the male reproductive part that produces pollen grains.
- B is correct: After fertilisation, the ovary develops into the fruit.
- C is correct: The stigma is the sticky surface that receives pollen grains during pollination.
- D is incorrect: Petals (not sepals) attract pollinators with bright colours. Sepals protect the flower bud.
Common mistake: Confusing sepals and petals.
2. (3) Butterfly – Insect [2]
Explanation:
Following the flow chart: Butterfly has no backbone → has an exoskeleton → classified as Insect.
- Bat is a mammal (has hair, produces milk), not a bird.
- Snake is a reptile (has scales), not an amphibian.
- Earthworm has no backbone, no exoskeleton, soft body → Worm, not Mollusc (molluscs have soft bodies but usually a shell, e.g., snail).
3. (2) Fallopian tube [2]
Explanation:
Fertilisation in humans occurs in the fallopian tube (oviduct), where the sperm meets the egg. The fertilised egg then travels to the uterus for implantation and development.
4. (2) Q [2]
Explanation:
Mammals have: backbone, hair/fur, produce milk, give birth to young alive (mostly).
- P has feathers → Bird
- Q has backbone, hair, produces milk → Mammal
- R has backbone, lays eggs, no feathers/hair → Reptile/Amphibian/Fish
- S has no backbone → Invertebrate
5. (3) It is a plant cell because it has chloroplasts and a cell wall. [2]
Explanation:
Plant cells have: cell wall, chloroplasts, large central vacuole. Animal cells lack cell wall and chloroplasts, and have only small vacuoles. Both have nucleus, cell membrane, cytoplasm.
6. (1) Seed → Seedling → Adult plant → Flower → Fruit → Seed [2]
Explanation:
Correct life cycle sequence: Seed germinates into seedling → grows into adult plant → produces flowers → after pollination and fertilisation, flowers develop into fruits containing seeds → cycle repeats.
7. (2) Ovule [2]
Explanation:
After fertilisation:
- Ovary → Fruit
- Ovule → Seed
The ovule contains the female reproductive cell; after fusion with male cell, it develops into the seed.
8. (4) Bacteria – Non-flowering plant [2]
Explanation:
- Mushroom: Fungus (not a plant) – but often grouped with non-flowering plants in primary classification
- Fern: Non-flowering plant (reproduces by spores) – correct
- Moss: Non-flowering plant (reproduces by spores) – correct
- Bacteria: Microorganism, not a plant – incorrectly classified as non-flowering plant
9. (3) Evaporation [2]
Explanation:
Evaporation requires heat from the Sun to change liquid water into water vapour. Condensation releases heat, precipitation is falling water, collection is accumulation.
10. (3) A and D [2]
Explanation:
Seeds need: Water (wet cotton wool), Air (oxygen), Suitable temperature (room temperature). Light is not needed for germination.
- A: Wet, room temp, light → Germinates (has water, air, warmth)
- B: Dry → No water → No germination
- C: Cold (0°C) → Unsuitable temperature → No germination
- D: Wet, room temp, dark → Germinates (has water, air, warmth; light not needed)
11. (2) The frog is both a predator and a prey. [2]
Explanation:
- Frog eats grasshopper (predator) and is eaten by snake (prey).
- Grass obtains energy from Sun (producer), not grasshopper.
- Eagle has least energy (top of pyramid, 10% transfer).
- Snake is a consumer, not producer.
12. (1) W [2]
Explanation:
Raincoat needs: Flexible (to wear), Waterproof (to repel rain). Transparency and electrical conductivity not needed.
- W: Flexible ✓, Waterproof ✓ → Suitable
- X: Not flexible, Transparent → Not suitable
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TuitionGoWhere Practice Paper - Science Primary 5 (SA2 Version 2) - Answer Key
SECTION A (56 marks)
| Question | Answer | Explanation |
|---|---|---|
| 1 | (3) A, B and C only | A: Anther produces pollen grains. B: Ovary develops into fruit after fertilisation. C: Stigma receives pollen during pollination. D is incorrect: Petals (not sepals) attract pollinators with bright colours. |
| 2 | (3) Butterfly – Insect | Butterfly has no backbone but has an exoskeleton → Insect. Bat is a mammal (hair, milk). Snake is a reptile (scales). Earthworm has no backbone, no exoskeleton, soft body → Worm (not mollusc). |
| 3 | (2) Fallopian tube | Fertilisation (fusion of sperm and egg) usually occurs in the fallopian tube. |
| 4 | (2) Q | Mammals have hair/fur and produce milk. Only Q has both characteristics. P is a bird (feathers). R could be reptile/amphibian/fish. S is an invertebrate. |
| 5 | (3) It is a plant cell because it has chloroplasts and a cell wall. | Plant cells have cell walls and chloroplasts; animal cells do not. Both have cell membranes and nuclei. Large central vacuole is also a plant cell feature. |
| 6 | (1) Seed → Seedling → Adult plant → Flower → Fruit → Seed | Correct life cycle sequence for flowering plants. |
| 7 | (2) Ovule | After fertilisation, the ovule develops into the seed. The ovary develops into the fruit. |
| 8 | (1) Mushroom – Non-flowering plant | Mushrooms are fungi, not plants. Ferns and mosses are non-flowering plants. Bacteria are micro-organisms (neither plants nor animals). |
| 9 | (3) Evaporation | Evaporation requires heat from the Sun to change liquid water into water vapour. Condensation releases heat. |
| 10 | (3) A and D | Seeds need water (wet), air, and suitable temperature (room temp) to germinate. Light is not required for germination. A (wet, room temp, light) and D (wet, room temp, dark) both meet the conditions. B is dry. C is too cold. |
| 11 | (2) The frog is both a predator and a prey. | Frog eats grasshopper (predator) and is eaten by snake (prey). Grass is a producer (makes own food). Energy decreases up the chain (eagle has least). Snake is a consumer. |
| 12 | (1) W | Raincoat needs to be flexible and waterproof. W has both properties. X is transparent (not needed). Y is not waterproof. Z is not flexible. |
| 13 | (2) All three bulbs will light up with equal brightness. | In a series circuit with a closed switch, current flows through all bulbs. Same current through each → equal brightness (assuming identical bulbs). |
| 14 | (2) It stores water in its stem. | This is a structural (physical) adaptation. Deep roots (1) is also structural but storing water in stem is the classic cactus adaptation. Opening stomata at night (3) is physiological. Shedding leaves (4) is behavioural/structural but less specific to cacti. |
| 15 | (3) Large intestine | The large intestine's main function is absorption of water and minerals from undigested food. |
| 16 | (3) The population of grass will increase. | Grasshoppers eat grass. Fewer grasshoppers → less grass eaten → grass population increases. Snakes eat mice/frogs (not directly grasshoppers in this web). Mice eat seeds (competition with grasshoppers? but grass is more direct). Hawks eat snakes/mice. |
| 17 | (3) Alveoli | Gaseous exchange (oxygen and carbon dioxide) occurs across the thin walls of the alveoli and surrounding capillaries. |
| 18 | (1) Nose → Trachea → Bronchi → Bronchioles → Alveoli | Correct anatomical path of inhaled air. |
| 19 | (2) The North pole of the magnet repels the North pole of the compass. | Like poles repel. Compass North points away from magnet North → repulsion. |
| 20 | (3) C | Object C rests at the bottom → density > water. Object D also sinks but "tilted" suggests it might be less dense than C or shaped differently. Object B suspended → density ≈ water. Object A floats → density < water. C is fully submerged and resting, indicating highest density among the sinking objects. |
| 21 | (1) Egg | The egg stage does not feed. Larva feeds actively. Pupa does not feed (but egg is the earliest non-feeding stage). Adult feeds on nectar/blood. |
| 22 | (3) Chloroplast | Chloroplasts (for photosynthesis) are found in plant cells, not animal cells. Nucleus, cell membrane, cytoplasm are in both. |
| 23 | (1) X – Reptiles, Y – Birds, Z – Mammals | X: scales, lay eggs, cold-blooded → Reptiles. Y: feathers, lay eggs, warm-blooded → Birds. Z: hair/fur, live birth, milk, warm-blooded → Mammals. |
| 24 | (2) It remains lit with the same brightness. | In a parallel circuit, each bulb has its own path to the battery. If one fuses (open circuit), the other path is unaffected. Voltage across remaining bulb unchanged → same brightness. |
| 25 | (2) A bird migrating to a warmer country during winter | Behavioural adaptation: action/behaviour for survival. (1) Thick fur = structural. (3) Webbed feet = structural. (4) Camouflage colour = structural. |
| 26 | (2) Solid → Liquid → Gas | Melting (solid to liquid) then boiling (liquid to gas) as heat is added. |
| 27 | (3) The shadow becomes larger. | Moving object closer to light source increases the angle of light blocked → larger shadow on screen. |
| 28 | (4) To reduce friction between moving parts | Lubricants (oil/grease) fill gaps between surfaces, reducing contact and friction. |
SECTION B (44 marks)
29. [4 marks]
a) The plant makes food in the leaves during photosynthesis. The food (sugar) is transported by the phloem (food-carrying tubes) in the stem to all parts of the plant, including the roots, for growth and storage. [2]
b) The roots absorb water and mineral salts from the soil. These are transported by the xylem (water-carrying tubes) in the stem to the leaves for photosynthesis. [2]
30. [3 marks]
a) Process A: Evaporation [1] b) Process B: Condensation [1] c) The water cycle ensures a continuous supply of fresh water on Earth. It distributes water across the globe, supports life, and regulates climate. [1]
31. [3 marks]
a) Organism X is a decomposer (or bacterium/fungus). [1] b) Decomposers break down dead organisms and waste matter into simpler substances (nutrients/mineral salts), which are returned to the soil/environment for plants to reuse. This recycles nutrients in the ecosystem. [2]
32. [4 marks]
a) Set-up A (with carbon dioxide): The limewater remains clear / colourless (or turns chalky slower if plant respires). Correction: In light, plant photosynthesises, using up CO₂. Limewater stays clear. [1] b) Set-up B (without carbon dioxide): The limewater turns chalky / milky (white precipitate). Correction: In light, no CO₂ for photosynthesis. Plant respires, releasing CO₂. Limewater turns chalky. [1] c) The experiment shows that carbon dioxide is necessary for photosynthesis. Without CO₂ (Set-up B), photosynthesis cannot occur (only respiration occurs, releasing CO₂). With CO₂ (Set-up A), photosynthesis occurs (using up CO₂). [2]
33. [3 marks]
a) The bulb in Circuit A (series) is brighter than each bulb in Circuit B (parallel). [1] b) In Circuit A (series), the two batteries provide higher voltage (3V + 3V = 6V equivalent) across the single bulb. In Circuit B (parallel), the voltage across each bulb is the same as one battery (3V). Higher voltage → more current → brighter bulb. [2]
34. [4 marks]
a) Material Y [1] b) The cooking pot must conduct heat well (good conductor of heat) to cook food evenly. The handle must be a poor conductor of heat (insulator) so it stays cool and safe to hold. Material Y conducts heat (suitable for pot) but the handle should be made of a material that does not conduct heat well (like plastic/wood). Wait, table shows Y conducts electricity, not necessarily heat. Usually good electrical conductors are good heat conductors. But the question asks based on table. Table: Y conducts electricity. Z conducts electricity and waterproof. W flexible, waterproof. X waterproof, transparent. Re-evaluating typical PSLE question: "Good conductor of heat" often linked to "conducts electricity" for metals. Pot = metal (conducts heat/electricity). Handle = insulator (does not conduct). b) Material Y conducts electricity (indicating it is a metal, which is a good conductor of heat), making it suitable for the pot body to transfer heat quickly. The handle should be made of a material that does not conduct electricity/heat (like plastic or wood) to prevent burns. [3]
35. [3 marks]
a) The stomach [1] b) The stomach secretes gastric juices containing enzymes (like pepsin) and hydrochloric acid. The enzymes break down proteins into simpler substances. The acid kills bacteria and provides an acidic medium for enzymes to work. [2]
36. [4 marks]
a) Repulsion is the only sure test for a magnet. [1] b) Attraction occurs between a magnet and a magnetic material (like iron/steel) AND between unlike poles of two magnets. Repulsion only occurs between like poles of two magnets. Therefore, if repulsion happens, the object must be a magnet. [2] c) Bring the object close to a known magnet's North pole. If it repels, it is a magnet (its North pole). If it attracts, test with the South pole. If it repels the South pole, it is a magnet (its South pole). If it attracts both poles, it is a magnetic material (not a magnet). [1]
37. [4 marks]
a) The circulatory system (heart, blood, blood vessels). [1] b) The heart pumps deoxygenated blood to the lungs to pick up oxygen. The oxygenated blood travels through the blood vessels to reach all parts of the body. At the capillaries, oxygen is exchanged with cells for respiration to release energy. [3]
38. [4 marks]
a) The water level in the measuring cylinder rises (or volume of water displaced increases). [1] b) The stone has a fixed volume. When submerged, it occupies space in the water, pushing the water out of the way (displacing it). The volume of water displaced equals the volume of the stone. [2] c) The mass of the stone remains the same. Mass is the amount of matter in an object and does not change with location or immersion in water. [1]
39. [4 marks]
a) Evaporation [1] b) Evaporation occurs at any temperature (below boiling point) and only at the surface of the liquid. Boiling occurs at a fixed temperature (100°C for water) and throughout the liquid (bubbles form). [2] c) Wind increases the rate of evaporation by blowing away the water vapour near the wet clothes, reducing the humidity around them, allowing more water molecules to escape into the air. [1]
40. [4 marks]
a) The length of the spring (or extension of the spring). [1] b) As the mass of the load increases, the length of the spring increases (spring stretches more). [1] c) The gravitational force (weight) pulling down on the load increases with mass. This stretches the spring further until the elastic spring force balances the weight. [2]
41. [4 marks]
a) The plant grows towards the light. / The shoot bends towards the light source. [1] b) Phototropism (directional growth response to light). [1] c) Auxins (plant hormones) accumulate on the shaded side of the stem. They stimulate cell elongation on that side, causing the stem to bend towards the light. [2]
Total: 100 marks
End of Answer Key