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Primary 5 Science Semestral Assessment 1 (Mid-Year) Paper 2
Free P5 Science SA1 Paper 2, Qwen3.7 Exam version, with questions, answers, and syllabus-aligned practice for Singapore students.
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Answer Key - Science Primary 5 SA1 Practice Paper (Version 2)
Topic Focus: Diversity
Section A (20 marks)
- (2) Dolphin, Seal, Platypus are all mammals. (Bat is a mammal, but Penguin is a bird. Shark is a fish. Frog is an amphibian.)
- (1) Ferns do not have flowers, reproduce by spores, and have vascular tissue. However, in the key provided: No Flowers -> B. Has Spores -> R. Ferns fit this. Mosses also have spores but lack vascular tissue (often simplified in P5 as non-vascular vs vascular). Between Fern and Moss, Fern is the standard example for spore-bearing vascular plants, but the key just says "Has Spores". Let's look at the options. A: Fern (Spores, No flower). B: Moss (Spores, No flower). C: Rose (Flower). D: Conifer (No flower, Seeds). The key distinguishes R (Spores) and S (No Spores). Both Fern and Moss have spores. Usually, P5 keys distinguish Ferns (has leaves/stems/roots) vs Mosses (no true roots/stems/leaves). If the key doesn't specify vascular tissue, both fit. However, Ferns are more commonly tested as the "spore plant" with distinct fronds. Let's assume R is Fern as it's the more complex spore plant often contrasted with flowering plants. Correction: Looking at standard P5 keys, if "Has Vascular Tissue" isn't a branch, Fern is the best fit for a plant with visible leaves/stems that isn't a flower.
- (3) Both fungi and bacteria are microorganisms. Fungi cannot make their own food (no chlorophyll). Bacteria generally cannot (except some). Neither lays eggs.
- (3) Camouflage helps it hide from predators.
- (2) Viruses are considered non-living by many definitions in primary science because they cannot reproduce independently (need a host).
- (4) Ferns have chlorophyll, reproduce by spores, and have vascular tissue (unlike mosses).
- (2) Spines reduce surface area, reducing water loss.
- (4) Webbed feet are a physical/structural feature. Hibernation and migration are behavioral. Color change can be physiological/behavioral.
- (3) Decomposers break down dead matter, recycling nutrients.
- (2) Bees get nectar; flowers get pollinated. Both benefit.
- (3) Group X has feathers and lays eggs. This describes birds. Eagle is a bird.
- (2) Mosses lack true vascular tissue and roots, so they absorb water through their surface and dry out easily in sun/wind.
- (3) Photosynthesis is a process for making food, not dispersing seeds.
- (2) Bacteria are single-celled, have no nucleus (prokaryotic), and some live in extreme environments.
- (2) Black skin absorbs heat; fat insulates.
- (2) Flowering plants produce seeds in fruits. Non-flowering include conifers (naked seeds) and spore plants.
- (3) High biodiversity increases stability and resilience.
- (3) Scales are physical; rolling is behavioral.
- (3) Spoilage is harmful.
- (1) Frogs eat insects. Fewer frogs mean fewer insects are eaten, so insect population increases.
Section B (36 marks)
21. Seed Dispersal (a)
- Seed A: Wind [1]
- Seed C: Water [1] (b) Seed B has hooks [1]. These hooks attach to the fur of animals [1], allowing the seed to be carried away. (c) It reduces competition for resources (water, sunlight, nutrients) between the parent plant and the offspring [1].
22. Classification (a)
- Group: 1B [1]
- Reason: Scorpions have 8 legs [1]. (Arachnids). (b) They give birth to live young OR they have hair/fur OR they feed their young with milk. [1] (Any one mammalian characteristic). (c) Insects have 6 legs [1], while spiders have 8 legs.
23. Population Graph (a)
- Species X: Rabbit (Prey) [0.5]
- Species Y: Fox (Predator) [0.5] (b) As the population of prey (X) increases, there is more food available for the predators (Y) [1]. This allows the predator population to increase due to better survival and reproduction [1]. (c) The population of Species X will increase rapidly at first [1] because there are no predators to eat them. However, it may later decrease due to lack of food or disease caused by overcrowding [1].
24. Microorganisms (a) Making yogurt / cheese / antibiotics / decomposing waste. [1] (b) The low temperature in the refrigerator slows down the growth and reproduction of bacteria/microorganisms [1]. This delays the spoilage of food [1]. (c) Carbon dioxide [1].
25. Leaf Structure (a) Palisade Mesophyll [1]. (b) To allow for the diffusion of gases (carbon dioxide and oxygen) within the leaf [1]. (c) Carbon dioxide [1].
26. Adaptations (a) Long eyelashes and closable nostrils prevent sand and dust from entering the eyes and nose [1] during sandstorms, protecting the camel [1]. (b) Blubber acts as an insulator [1], reducing heat loss to the cold environment. (c) Migration / Hibernation / Nocturnal activity. [1]
27. Classification Concepts (a) Scientific names are universal and avoid confusion caused by different common names in different languages/regions [1]. (b)
- Mushroom: Fungus [✓] [1]
- Fern: Non-flowering Plant [✓] [1]
- Orchid: Flowering Plant [✓] [1]
28. Food Web (a)
- Producer: Grass [1]
- Tertiary Consumer: Snake or Eagle or Fox [1]. (Grass->Grasshopper->Frog->Snake. Snake is tertiary. Grass->Rabbit->Fox. Fox is secondary. Wait. Grass(1)->Grasshopper(2)->Frog(3)->Snake(4). Snake is Tertiary. Eagle eats Snake, so Eagle is Quaternary. Fox eats Rabbit, so Fox is Secondary. So Snake or Eagle is acceptable if Eagle eats Frog directly? Diagram shows Snake->Eagle. So Snake is Tertiary. Eagle is Quaternary. Let's accept Snake.) (b) The population of grasshoppers will increase [1]. This is because frogs are their predators, and with fewer frogs, fewer grasshoppers are eaten [1]. (c) Decomposers break down dead organisms and waste, returning nutrients to the soil [1] for plants to use.
29. Experiment (a) The amount of light (or presence of light) [1]. (b) The amount of water / type of plant / size of pot / soil type. [1] (c) The plant in Pot B could not perform photosynthesis because there was no light [1]. Therefore, it could not make food (glucose) to grow and stay healthy, causing it to become yellow (lack of chlorophyll production) and weak [1].
30. Biodiversity (a) Biodiversity is the variety of living things (species) in an ecosystem [1]. (b) Deforestation / Pollution / Overhunting / Urbanization. [1] (c) Establishing nature reserves / Replanting trees / Reducing pollution / Enforcing laws against poaching. [1]