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Primary 5 Science Weighted Assessment 3 (Term 3) Paper 2
Free P5 Science WA3 Paper 2, Qwen3.7 Exam version, with questions, answers, and syllabus-aligned practice for Singapore students.
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TuitionGoWhere Practice Paper - Science Primary 5 (WA3 Version 2)
Answer Key and Marking Scheme
Section A (20 marks)
- (1) Bat, Whale, and Dolphin are all mammals. They give birth to live young and feed them with milk. Penguins are birds; Sharks are fish; Frogs are amphibians.
- (3) Plant Y. Ferns do not have flowers (Go to B) and have spores on the underside of leaves (Yes).
- (2) Feathers are unique to birds. Other animals lay eggs (reptiles, amphibians), have four limbs (mammals, reptiles), or use lungs (mammals, reptiles).
- (2) If frogs decrease, there are fewer predators for grasshoppers, so the grasshopper population will increase.
- (2) Thick, waxy skin reduces water loss through transpiration, which is crucial in a dry desert.
- (3) Plant C. Mosses have chlorophyll (Yes), reproduce by spores (Yes), but do not have true roots, stems, or leaves (No). Plant D is likely a fern.
- (3) Fat acts as an insulator to keep the bear warm in freezing temperatures.
- (3) Fungi are decomposers or saprophytes; they do not photosynthesize.
- (3) C (Streamlined body). This shape reduces drag (water resistance).
- (3) Webbed feet are a physical (structural) feature. Hibernation and migration are behavioral; color change can be physiological/behavioral.
- (2) Mutualism. Both the tree (protected from insects) and the bird (gets food/shelter) benefit.
- (1) Spider (Arachnid), Snail (Mollusc), Earthworm (Annelid) are all invertebrates.
- (2) Long roots reach deep water tables in arid regions.
- (2) Housefly. It is an insect (invertebrate). Goldfish, Penguin, and Toad are vertebrates.
- (3) Thorns deter animals from eating the plant.
- (3) Not all living things move from place to place (e.g., plants).
- (3) Amphibian. Cold-blooded, soft-shelled eggs, dual habitat, dual breathing.
- (2) Mimicry is a behavioral/structural adaptation to avoid predation.
- (2) Grass (Producer) and Rabbit (Consumer).
- (2) Decomposers recycle nutrients by breaking down dead organic matter.
Section B (36 marks)
21. (a) Leaf B (Needle-like). [1] Reason: Needle-like leaves have a smaller surface area, which reduces water loss through transpiration. This is important in cold environments where water may be frozen and unavailable. [1] (b) Thick/Fleshy skin OR Spines instead of leaves. [1] (Accept: Reduced surface area). (c) To make food for the plant through photosynthesis. [1]
22. (a) Snake OR Bird OR Fox. [1] (Any animal that eats another and is eaten by another). (b) The population of grasshoppers will increase. [1] Reason: Frogs are predators of grasshoppers. With fewer frogs, fewer grasshoppers are eaten, allowing their numbers to grow. [1] (c) Grass. [1]
23. (a) [3 marks, 0.5 each] P: Reptile Q: Mammal R: Bird S: Amphibian T: Fish (b) Animal: S [1] Reason: It has moist skin and breathes through lungs and skin, which are characteristic of amphibians. It also lays eggs. [1]
24. (a) To prevent evaporation of water directly from the surface of the water in the test tube. [1] This ensures that any water loss is due to the plant, not the environment. (b) Test Tube: A [1] Explanation: Test tube A has more leaves (10 leaves) than Test tube B (2 leaves). More leaves mean a larger total surface area for stomata, leading to a higher rate of transpiration (water loss). [1] (c) Transpiration. [1]
25. (a) To obtain oxygen for respiration because the muddy soil lacks sufficient oxygen. [1] (b) The glands remove excess salt from the plant, preventing salt toxicity. [1] (c) Flexible stems to bend with the wind without breaking OR Strong roots to anchor the plant. [1]
26. (a) Sexual reproduction. [1] (Involves fusion of male and female gametes/eggs). (b) Larva (or Caterpillar). [1] (c) It is the stage where the body undergoes metamorphosis (major changes) to transform from a larva into an adult. [1] The pupa is protected while these changes occur. [1]
27. (a) No. [1] Explanation: The key distinguishes between Housefly (2 pairs of wings) and Mosquito (1 pair of wings). A bee has 2 pairs of wings, so it would be identified as a Housefly, which is incorrect. The key does not have a specific branch for bees. [1] (b) [2 marks for correct logic] Start -> Has wings? Yes -> Has 6 legs? Yes -> Bee No (Has 8 legs) -> Scorpion (Note: Accept any logical flowchart that correctly separates them based on legs/wings).
28. (a) The populations show a cyclical pattern. [1] When the rabbit population increases, the fox population increases later. When the rabbit population decreases, the fox population decreases later. [1] (b) Foxes feed on rabbits. [1] When the rabbit population decreases, there is less food available for the foxes, causing some foxes to starve or leave, leading to a decrease in their population. [1]
29. (a) Criterion: Natural vs. Man-made OR Conductor vs. Insulator OR Biodegradable vs. Non-biodegradable. [1] (b) Example using Natural vs. Man-made: [2] Group 1 (Natural): Wooden chair, Cotton shirt Group 2 (Man-made/Synthetic): Gold ring (processed), Plastic bottle (Note: Marks depend on consistency with the chosen criterion).
30. (a) [2 marks]
- Plant cells have a cell wall; animal cells do not.
- Plant cells have chloroplasts; animal cells do not. (Alternative: Plant cells have a large central vacuole; animal cells have small/temporary vacuoles). (b) Chloroplast. [1] (c) Animal cells do not perform photosynthesis because animals are consumers and obtain food by eating other organisms. [1]
31. (a) Liquid C (56C). [1] It has the lowest boiling point. (b) Liquid (or Gas/Vapor if strictly at boiling, but at 80 it is liquid). [1] Water boils at 100C, so at 80C it is still a liquid.
32. (a) No. [1] Reason: The switch is open, so the circuit is incomplete. Electricity cannot flow. [1] (b) The brightness will decrease (dimmer). [1] Adding bulbs in series increases resistance, reducing current.
33. (a) A: Trachea (Windpipe) [1] B: Lungs [1] (b) The diaphragm moves down (contracts/flattens). [1] This increases the volume of the chest cavity, drawing air in.
34. (a) Radicle (or Root embryo). [1] (b) Water softens the seed coat and activates enzymes that break down stored food for the growing embryo. [1]
35. (a) At the poles (North and South poles). [1] (b) The magnetic field is strongest at the poles. [1]
36. (a) The fulcrum is the pivot point around which the lever turns. [1] (b) It becomes easier. [1] Explanation: Moving the load closer to the fulcrum decreases the load distance. According to the principle of moments, less effort is required to lift the load when the load arm is shorter. [1]
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