AI Generated Quiz
Primary 6 PSLE Science Diversity Quiz
Free P6 PSLE Science Diversity quiz, Kimi2.6 AI version, with questions, answers, and PSLE-focused practice for Singapore students.
These static practice materials are generated from the site's syllabus and paper-generation workflow, with source and model context shown so students and parents can evaluate the material before use.
Questions
Free quiz and exam paper access
Enter your details to view this paper
Your access is remembered on this device.
Answers
Primary 6 PSLE Science Quiz - Diversity: Answer Key
Total Marks: 40 marks
Section A: Multiple Choice (1 mark each)
| Q | Answer | Explanation |
|---|---|---|
| 1 | C | All living things breathe, grow, and reproduce. However, only plants and some bacteria can photosynthesise—animals and fungi cannot. Photosynthesis is NOT a universal characteristic of all living things. |
| 2 | C | The organism has chlorophyll (for making food) and cell walls—these are the defining features of Kingdom Plantae. Fungi have cell walls but no chlorophyll; animals have no cell walls; protists are a diverse group that may have chlorophyll but typically lack the distinctive cell wall structure of plants. |
| 3 | B | An earthworm does not have wings, does not have 6 legs, and has moist skin (it breathes through its skin). Following the key: No wings → no 6 legs → moist skin → Group D. Students often confuse this with amphibians, but the key leads to moist skin as the final distinguishing feature. |
| 4 | B | P (bird) and S (reptile) both lay eggs with hard or leathery shells on land. Q is an amphibian (soft eggs in water); R is a mammal. The key grouping is amniotic eggs adapted for land. |
| 5 | C | Producers make their own food through photosynthesis. The mangrove tree is the only producer listed—it produces glucose from sunlight. Caterpillars, small fish, and crabs are all consumers. |
| 6 | C | Kingdom Monera (bacteria) are prokaryotic—they lack a true nucleus (no nuclear membrane). This is their defining feature. Not all bacteria cause disease (many are beneficial), and they live in diverse environments, not just water. |
| 7 | B | To determine if organisms belong to the same species, scientists look at reproductive compatibility—organisms of the same species can produce fertile offspring. Flower structure and number of petals indicate related species within the same genus or family. External features like height, leaf colour, or light preference vary with environment and are unreliable for species identification. |
| 8 | C | Organism Y: has a backbone (vertebrate), wings (birds have modified forelimbs as wings), no hair/fur (birds have feathers, not hair—though the table doesn't mention feathers, the combination of wings + backbone + constant body temperature is diagnostic), and constant body temperature (warm-blooded). W is a mammal; X and Z are invertebrates. |
| 9 | B | Biodiversity provides ecosystem stability through functional redundancy—if one species is lost, others can perform similar roles (e.g., pollination, nutrient cycling). Beauty (A) and naming (C) are human conveniences, not ecological functions. D is incorrect because biodiversity does not prevent extinction; it buffers against its consequences. |
| 10 | B | Fungi are saprophytic—they secrete enzymes to break down dead organic matter and absorb the nutrients. They cannot photosynthesise (no chlorophyll), do not typically catch prey (that's carnivorous plants and some animals), and do not form food webs as producers. |
Section B: Matching and Classification
11. (a) A (mushroom) [1 mark]
The mushroom is a fungus. If students selected both A and need to identify another, accept A only—the question asks which two, but A is the only fungus shown. (Note: If B is misidentified, clarify that ferns are plants, not fungi. The answer expected is A for definite; if the diagram includes another fungus-like organism, adjust accordingly. Based on standard P6 content, only the mushroom is fungal.)
Actually reviewing: A (mushroom) is fungal. No other organism is fungal. If marking strictly, A is correct; if question implies two, there may be diagram ambiguity. Standard answer: A.
(b) B (fern) [1 mark]
Ferns are non-flowering plants that reproduce by spores (visible as sori on frond undersides), not seeds or flowers.
12. Complete table: [2 marks — ½ mark each]
| Feature | Bacteria | Fungi |
|---|---|---|
| Cell structure | (i) Prokaryotic | Eukaryotic |
| Chlorophyll present? | No | (ii) No |
| Method of nutrition | Absorption | (iii) Absorption |
| Example | (iv) E. coli / Lactobacillus / any named bacterium | Mushroom |
Teaching notes:
- Prokaryotic = no membrane-bound nucleus, DNA free in cytoplasm
- Fungi never have chlorophyll (they are heterotrophic decomposers)
- Both bacteria and fungi absorb nutrients—bacteria through cell membrane, fungi through hyphae
- Common mistake: Students confuse fungi with plants; emphasise NO chlorophyll in fungi
13. (a) [1 mark]
Habitat X producer: Algae (or water lily)
Habitat Y producer: Grass
Either answer accepted if the organism is clearly a producer (photosynthetic). Water lily is also correct.
(b) [1 mark]
Sample answer: Animals in Habitat X (pond) breathe using gills or can absorb oxygen from water, while animals in Habitat Y (grassland) breathe using lungs through nostrils/mouths.
Or: Habitat X has animals that are adapted to aquatic breathing (gills, breathing tubes), while Habitat Y animals have air-breathing adaptations (lungs, tracheae in insects).
14. (a) 18 cm² [1 mark]
Read directly from graph at Day 3.
(b) [1 mark]
Prediction: Mold growth would be slower / less area covered.
Explanation: The low temperature (4°C) slows down the reproduction rate of mold spores / reduces enzyme activity in the mold, so less growth occurs. Mold grows best in warm, moist conditions.
15. [2 marks — ½ mark each]
| Dispersal Method | Letter |
|---|---|
| By water | Q (coconut) |
| By animals (externally) | R (burr with hooks) |
| By wind | P (dandelion parachute) |
| By explosive mechanism | S (exploding pod) |
Teaching notes:
- P — Feathery parachute increases surface area, catches wind
- Q — Fibrous husk provides buoyancy, waterproof shell protects embryo
- R — Hooks attach to animal fur/clothing for transport
- S — Coiled spring mechanism builds tension; when dry, pod bursts open
Section C: Open-Ended Questions
16. (a) [2 marks]
The bean plant grew taller because:
- It carried out photosynthesis using chlorophyll in its leaves [1]
- The glucose produced was used for growth (cell division and elongation), and with adequate water and minerals from the soil, the plant could increase in height [1]
Marking descriptor:
- Mention of photosynthesis making food/glucose → 1 mark
- Link to growth/energy for cell processes → 1 mark
(b) [2 marks]
The lower parts of the Elodea died because:
- The lower parts were shaded by upper leaves / received less light [1]
- Without sufficient light, these parts could not photosynthesise effectively to make enough food for survival; OR oxygen depletion in lower water levels may occur [1]
Alternative acceptable answer: Lower parts are older and naturally senesce; or algae/decor growth on glass blocked light.
Marking descriptor:
- Reason for reduced photosynthesis (light blocked/old age) → 1 mark
- Consequence (insufficient food/energy, so cells die) → 1 mark
17. (a) [2 marks]
The frog population would increase initially [1]
Explanation: Without snakes (their predator), fewer frogs would be eaten. With less predation pressure, more frogs would survive to reproduce, leading to population increase [1]
Note: Accept "increase" with explanation; bonus reasoning that food shortage or disease may later cause decline is valid but not required.
(b) [2 marks]
The hawk population would decrease [1]
Explanation: Pesticide on grass → accumulated in grasshoppers → accumulated in frogs → accumulated in snakes → biomagnification in hawks. OR: Pesticide kills grasshoppers directly, reducing food for frogs, then snakes, then hawks, causing food shortage at each level [1]
Marking descriptor:
- Correct trend (decrease) → 1 mark
- Explanation of bioaccumulation/biomagnification OR disruption of food chain/food shortage → 1 mark
18. (a) [1 mark]
Nitrogen-fixing bacteria and nitrifying bacteria
(Any two of: nitrogen-fixing bacteria, nitrifying bacteria, decomposers that break down organic matter)
(b) [2 marks]
Farmers grow legumes because:
- Legume roots contain nitrogen-fixing bacteria (Rhizobium) that convert atmospheric nitrogen into ammonium compounds [1]
- These nitrogen compounds enrich the soil with nitrates that the next crop can absorb for growth, reducing need for artificial fertilisers [1]
Marking descriptor:
- Mention of nitrogen-fixing bacteria in root nodules → 1 mark
- Benefit to soil/ subsequent crops / natural fertiliser → 1 mark
19. (a) [1 mark]
Temperature (of storage environment)
(b) [1 mark]
Any two from:
- Type/brand of bread
- Amount/moisture content of bread
- Volume/size of bread slice
- Exposure to air/time before sealing
- Amount of mold spores initially present (though hard to control)
½ mark each, maximum 1 mark
(c) [2 marks]
| Setup | Prediction | Explanation |
|---|---|---|
| A (30°C) | Most mold / largest area covered [½] | Warm temperature provides optimal conditions for mold spore germination and growth; enzymes work fastest [½] |
| B (25°C) | Moderate mold growth [½] | Room temperature allows some growth but slower than at 30°C [½] |
| C (4°C) | Least mold / little to no visible mold [½] | Cold temperature slows enzyme activity / stops spore germination; mold becomes dormant [½] |
Mark for correct trend across all three (A>B>C or equivalent) → 1 mark
Mark for temperature effect on enzyme/reproduction rate → 1 mark
Note: If predictions and explanations show understanding but vary in exact wording, award marks for scientific reasoning.
20. (a) [2 marks]
Mangroves maintain high biodiversity because:
- They provide many different habitats/microhabitats (roots in water, canopy, mudflats) supporting varied niches [1]
- They are productive ecosystems with high nutrient cycling; fallen leaves decompose to feed detritivores, supporting complex food webs [1]
Alternative: Mangroves protect coastlines, reducing erosion and maintaining water quality that aquatic organisms need.
(b) [2 marks]
Any two valid impacts (1 mark each):
- Habitat destruction/fragmentation — construction destroys nesting/breeding sites
- Noise/light pollution — disrupts bird migration patterns and animal behaviour
- Water pollution — runoff from construction sites pollutes water, affecting aquatic organisms
- Reduced food availability — removal of vegetation reduces food sources
- Increased human disturbance — recreation, litter, direct harm to wildlife
END OF ANSWER KEY