Primary 5 Science Diversity Quiz

Primary 5 Science Quiz - Diversity: Answer Key

Total Marks: 40 marks

Section A: Multiple Choice (Questions 1–8)

2 marks each

1. B — Fern, moss, grass [2 marks]

Explanation: Ferns and mosses are non-flowering plants, and grass is a flowering plant. All three are plants. Mushrooms (A, C) and mould/yeast (C) are fungi, not plants. Birds (D) are animals, not plants.

Common mistake: Choosing A because fern and rose are plants but forgetting mushroom is a fungus.

2. A — Mammals and reptiles [2 marks]

Explanation: Crocodiles are reptiles (lay eggs on land, have scales). Whales are mammals (give birth to live young, feed young with milk). This difference in reproduction method is a key way to distinguish these two groups of vertebrates.

Key concept: Reproduction method (eggs vs. live birth) is a major classification criterion for vertebrates.

3. C — All invertebrates do not have bones [2 marks]

Explanation: Looking at the flowchart, invertebrates are defined as animals without backbones (no vertebral column/bones). This is the defining characteristic.

• A is incorrect: Fish are vertebrates but are cold-blooded, not warm-blooded.
• B is incorrect: While most flowering plants produce seeds, some flowering plants can reproduce vegetatively (without seeds) as well.
• D is incorrect: Some non-flowering plants like ferns reproduce by spores, but others like mosses also reproduce by spores; however, the word "only" makes this too absolute and incorrect since some non-flowering plants can reproduce in other ways.

4. A — P [2 marks]

Explanation: Fish are vertebrates (have backbone/backbone), live in water, do NOT have feathers, and LAY EGGS.

• Organism P: backbone ✓, water ✓, no feathers ✓, lays eggs ✓ — matches fish
• Organism Q: has feathers — this is a bird
• Organism R: no backbone — invertebrate (perhaps a jellyfish or shrimp)
• Organism S: no eggs — this is a mammal (like a whale or dolphin) that gives live birth

5. B — do not carry out photosynthesis [2 marks]

Explanation: Fungi are not plants because they cannot make their own food through photosynthesis. They lack chlorophyll and chloroplasts. Instead, fungi absorb nutrients from decaying matter or living hosts.

• A is incorrect: Neither plants nor fungi can move from place to place as adults.
• C is incorrect: Fungi do grow and reproduce (by spores).
• D is incorrect: Fungi do need water to survive and grow.

Key concept: The ability to photosynthesize (make own food) is a defining feature of plants that fungi lack.

6. C — Insects [2 marks]

Explanation: Insects are defined by having six legs, three body parts (head, thorax, abdomen), and usually one or two pairs of wings.

• Crustaceans (A) include crabs and shrimps with more than 6 legs and typically two body parts.
• Arachnids (B) such as spiders have 8 legs and two body parts.
• Molluscs (D) such as snails have soft bodies and no distinct jointed legs.

7. C — Some bacteria can make their own food [2 marks]

Explanation: Some bacteria are chemosynthetic — they can make their own food using chemical energy instead of sunlight. Examples include bacteria found near deep-sea vents.

• A is incorrect: Many bacteria are beneficial (e.g., in yoghurt, nitrogen-fixing bacteria in soil).
• B is incorrect: Bacteria are much smaller than plant cells; bacteria are single-celled microorganisms.
• D is incorrect: Bacteria do NOT have a true nucleus (they are prokaryotes) and do NOT have chloroplasts.

8. A — W = bird; Z = reptile [2 marks]

Explanation: Birds are warm-blooded (endothermic), meaning they maintain a constant body temperature regardless of surroundings. Reptiles are cold-blooded (ectothermic), meaning their body temperature changes with the environment.

• W and Y have constant body temperature = warm-blooded = birds or mammals
• X and Z have changing body temperature = cold-blooded = reptiles, amphibians, or fish

Since the question asks for bird and reptile, and birds are the only option with feathers (typically), W = bird and Z = reptile is correct.

Section B: Fill in the Blanks and Short Answer (Questions 9–14)

9. [4 marks: 1 mark for each correct pair of answers]

(a) Living things can be grouped into Plants and Animals. [Given]

(b) Animals can be further grouped into those with backbones, called vertebrates, and those without backbones, called invertebrates.

(c) Vertebrates include mammals, birds, fish, reptiles, and amphibians. [Either order]

(d) Plants that produce seeds are called flowering plants, while those that do not produce seeds are called non-flowering plants. [Accept: seed-producing / non-seed-producing]

10. (a) Q (1 mark); Reason: It has needle-like leaves, which is characteristic of conifers/pine trees, a type of non-flowering plant. (1 mark) [2 marks total]

Explanation: Non-flowering plants like conifers (pine, fir, spruce) have needle-like or scale-like leaves instead of broad leaves. Leaf P has net-like veins typical of dicot flowering plants. Leaf R is compound, common in some flowering plants like peas or mimosa. Leaf S has parallel veins typical of monocot flowering plants like grasses or lilies.

(b) Explanation: Scientists use leaf shape and vein patterns because these features are consistent within plant groups and help identify whether a plant is a flowering or non-flowering plant. (1 mark) For example, broad leaves with net-like veins usually indicate flowering plants (dicots), while needle-like leaves usually indicate non-flowering conifers. These features are observable and reliable for classification. (1 mark) [2 marks total]

11. (a) W (frog) [1 mark]

(b) A bat is classified as a mammal because it has fur/hair on its body and gives birth to live young (rather than laying eggs). (1 mark for each correct feature, max 2 marks) [2 marks total]

Explanation: Although bats have wings and can fly like birds, they possess mammal characteristics: fur/hair, live birth, and females feed their young with milk. Birds have feathers, lay eggs, and do not have fur.

(c) Any two of: [2 marks total — 1 mark each]

• Layer of fat (blubber) under the skin insulates against cold
• Thick, waterproof feathers provide insulation and keep out water
• Streamlined body reduces heat loss and helps swimming
• Darker feathers on back absorb heat from sunlight
• Huddling together in groups to share body heat

12. (a) Any one of: [1 mark]

• Making yoghurt / cheese from milk
• Breaking down waste in composting / decomposition
• Nitrogen fixation in soil for plant growth
• Making medicine (antibiotics like penicillin)
• Sewage treatment

(b) Any one of: [1 mark]

• Causing diseases (food poisoning, sore throats, etc.)
• Making food rot / spoil
• Causing tooth decay

(c) Yeast is a fungus that ferments the sugars in bread dough. (1 mark) This process produces carbon dioxide gas, which makes the bread rise and become soft and fluffy. (1 mark) [2 marks total]

Explanation: Fermentation is a process where yeast breaks down sugar without using oxygen, producing carbon dioxide and a small amount of alcohol (which evaporates during baking). The CO₂ creates air pockets in the dough.

13. (a) Organism D (1 mark); Explanation: It has no nucleus (prokaryotic cell structure), which is the defining feature of bacteria. All other organisms have a nucleus. Additionally, it is unicellular and can move. (1 mark) [2 marks total]

Key concept: Bacteria are prokaryotes — they lack a membrane-bound nucleus and other organelles.

(b) B and C [1 mark — both required]

(c) Organisms that make their own food (producers/autotrophs) are important because they convert energy from sunlight into food through photosynthesis. (1 mark) This food then provides energy for all other organisms in the ecosystem (consumers) that cannot make their own food. They are the base of the food chain. (1 mark) [2 marks total]

14. (a) Different types of plants support more different types of animals (providing various foods and habitats). (1 mark) If one plant type fails due to disease or weather, other plants can still support the ecosystem, making it more resilient. (1 mark) [2 marks total]

(b) Threat: Any one of — deforestation, pollution, overharvesting, urban development, climate change (1 mark)

Solution: Matching solution — reforestation, protected reserves/national parks, sustainable harvesting, reducing pollution, habitat corridors (1 mark) [2 marks total]

Section C: Application and Reasoning (Questions 15–20)

15. (a) L (1 mark); Reason: It is the only specimen that can make its own food (has the characteristic of a plant/producer). (1 mark)

(b) Specimen M has feathers while Specimen J does not have feathers (J has wings but no feathers). (1 mark) Having feathers is a defining characteristic of birds, so M is a bird and J is likely an insect. (1 mark) [2 marks total]

Alternatively: J could also be accepted as a bat (mammal) if student explains about mammal features vs bird features.

(c) Amphibian (1 mark) [Accept: frog/toad/newt/salamander group]

Explanation: Specimen K can move, cannot make its own food, lacks wings and feathers, but has moist skin. These are key characteristics of amphibians like frogs.

16. (a) T (1 mark); Explanation: Following the key: Start at "Does the plant have flowers?" → No. Then "Does the plant have cones?" → No. This leads to T, which has neither flowers nor cones. Ferns are non-flowering plants that do not produce cones (unlike conifers); they reproduce using spores. (1 mark) [2 marks total]

(b) Leaf shape: Plant P has broad leaves while Plant Q does not (has narrow/non-broad leaves). (1 mark)

(c) Pine trees are non-flowering plants because they do not produce flowers or fruits. (1 mark) Their seeds develop on the scales of cones rather than inside fruits. The cone is not a flower — it is a reproductive structure unique to conifers/gymnosperms. (1 mark) [2 marks total]

17. (a) Seagrass is classified as a plant because it has true roots, stems, and leaves — the structural organization of a plant. (1 mark) Seaweed lacks these true structures; it is simpler in body organization and belongs to the algae/protists group. (1 mark) [2 marks total]

(b) Seaweed (1 mark); Explanation: The organism has no true roots, stems, or leaves, which matches the description of seaweed in the table. Seagrass would have all three structures. (1 mark) [2 marks total]

18. (a) They all have a hard outer skeleton (exoskeleton). (1 mark)

(b) Crustaceans (1 mark)

(c) The exoskeleton provides protection from predators and physical damage. (1 mark) It also helps prevent water loss from the body, which is important for survival on land. (1 mark) [2 marks total]

Alternative acceptable answer: The exoskeleton provides support and a framework for muscles to attach to, enabling movement.

19. (a) Flowering plant: Water lily (accept if student names any plant with visible flowers: water lily) (1 mark)

Non-flowering plant: Algae (accept: duckweed if student considers it non-flowering, but duckweed is actually a flowering plant; algae is the clearest correct answer) (1 mark) [2 marks total]

Note: Duckweed does flower but flowers are tiny and often overlooked; algae is the safest correct answer for non-flowering.

(b) Similarities: Any two of — all have backbones/are vertebrates; all can swim in water; all are animals/consumers; all breathe oxygen (2 marks — 1 mark each)

Difference in breathing: Fish breathe using gills; frog breathes using lungs and moist skin (or just lungs/skin); turtle breathes using lungs. (1 mark for any accurate difference stated) [3 marks total]

(c) Different types of plants provide different food sources and habitats for different organisms. (1 mark) If one type of plant is affected by disease or environmental change, the other types can continue to support the ecosystem, making it more stable and resilient. (1 mark) [2 marks total]

20. (a) [5 marks — 1 mark each]

Key reasoning:

• Fern has vascular tissues (xylem/phloem) and reproduces by spores — non-flowering but vascular
• Moss lacks true vascular tissues — non-vascular plant
• Cactus produces flowers (though may be brief) — flowering plant
• Mushroom is a fungus, not a plant
• Bacterium is a single-celled microorganism/prokaryote

(b) The mushroom is not a plant because it cannot carry out photosynthesis (has no chlorophyll/chloroplasts). (1 mark) It absorbs nutrients from decaying matter as a decomposer, rather than making its own food like plants do. (1 mark) [2 marks total]

(c) The thick, fleshy stem stores water for long periods. (1 mark) This helps the cactus survive in dry/desert conditions where rainfall is scarce and irregular. (1 mark) [2 marks total]

Alternative: The thick waxy covering on the stem also reduces water loss through evaporation.

TOTAL: 40 MARKS

Marking notes:

• Accept equivalent scientifically accurate phrasing
• Do not penalize spelling errors unless they change the meaning
• For "explain" questions, award marks only if reasoning is provided, not just identification