Primary 4 Science Semestral Assessment 2 (End of Year) Paper 4

TuitionGoWhere Practice Paper - Science Primary 4 (SA2 Version 4) - Answer Key

Subject: Science
Level: Primary 4
Paper: SA2 (Version 4)
Total Marks: 60

SECTION A: Multiple-Choice Questions (28 marks)

1. Answer: (2) Bacteria, yeast, mould [2]

Explanation:

• Living things need air, food, and water; they grow, reproduce, and respond to changes.
• Bacteria, yeast, and mould are all microorganisms (fungi/bacteria) — they are living.
• Mushroom and moss are living, but rock is non-living → (1) is incorrect.
• Cloud, rain, wind are non-living → (3) is incorrect.
• Sand, water, soil are non-living → (4) is incorrect.

Common mistake: Thinking mushrooms are non-living because they don't move. They are fungi — living things.

2. Answer: (2) X: Fern, Y: Fish [2]

Explanation:
From the classification chart:

• Plants → Flowering / Non-Flowering. Fern is a non-flowering plant → fits X under Plants → Non-Flowering.
• Animals → Vertebrates / Invertebrates. Fish is a vertebrate → fits Y under Animals → Vertebrates.

Check other options:

• (1) Mushroom is fungi (not a plant), Bird is vertebrate → X wrong.
• (3) Bacteria is microorganism (not plant/animal in this classification), Insect is invertebrate → X wrong.
• (4) Moss is non-flowering plant (correct for X), but Snake is vertebrate (correct for Y) — wait, moss is non-flowering plant, snake is vertebrate. But the chart shows X under Non-Flowering Plants and Y under Vertebrates. Option (4) has Moss (correct for X) and Snake (correct for Y). However, option (2) has Fern (non-flowering plant) and Fish (vertebrate). Both (2) and (4) seem correct? Let's re-examine.

Wait, the chart in the question: "Living Things branches into Plants and Animals. Plants branches into Flowering and Non-Flowering. Animals branches into Vertebrates and Invertebrates." So X is under Non-Flowering Plants, Y is under Vertebrates.

Option (2): X = Fern (non-flowering plant ✓), Y = Fish (vertebrate ✓)
Option (4): X = Moss (non-flowering plant ✓), Y = Snake (vertebrate ✓)

Both are correct? But only one answer allowed. Let's check typical exam patterns. Usually, they want the most common examples. Fern and fish are very standard examples. Moss is also non-flowering. Snake is vertebrate. Hmm.

Actually, looking at the template bank: "Fern" is explicitly mentioned as non-flowering plant. "Fish" as vertebrate. "Moss" is also non-flowering. "Snake" is vertebrate. But in the classification chart description, it says "Non-Flowering (Fern, Moss)" — both are listed. And "Vertebrates (Fish, Bird, Mammal)" — fish is listed, snake is not explicitly listed but is a vertebrate (reptile).

However, in the question's chart description for Q20, it says "Non-Flowering (Fern, Moss)" and "Vertebrates (Fish, Bird, Mammal)". So both fern and moss are non-flowering; fish is vertebrate, snake is also vertebrate but not in the listed examples.

But the question is Q2, not Q20. The chart for Q2 is described similarly. Since both (2) and (4) are factually correct, but (2) uses examples that are more commonly taught as primary examples (fern for non-flowering, fish for vertebrate), and (4) uses moss (also correct) and snake (correct but reptile, not in the typical "Fish, Bird, Mammal" trio). In many P4 textbooks, the vertebrate groups taught are Fish, Amphibian, Reptile, Bird, Mammal. But the chart only shows "Vertebrates" with examples Fish, Bird, Mammal. Snake is a reptile, not listed. So (2) is better aligned with the given chart examples.

Marking note: Accept (2) as the intended answer based on typical textbook examples shown in the chart.

3. Answer: (3) Bala and Devi only [2]

Explanation:

• Ali: Incorrect. Plants are living but cannot move from place to place (they move parts, e.g., towards light, but not locomotion).
• Bala: Correct. All living things need air, food, and water.
• Cindy: Incorrect. Not all living things lay eggs (e.g., mammals give birth, plants produce seeds/spores).
• Devi: Correct. All living things grow and respond to changes (sensitivity).

4. Answer: (4) D [2]

Explanation:

• Part D is the root.
• Function of roots: Absorb water and mineral salts from the soil, and anchor the plant.
• A = Flower (reproduction), B = Leaf (makes food), C = Stem (transport/support).

5. Answer: (2) A and C only [2]

Explanation:

• A. Reproduce by spores → True (fungi reproduce by spores, not seeds).
• B. Make their own food → False (fungi are decomposers; they feed on dead/decaying matter, no chlorophyll).
• C. Feed on dead or decaying matter → True (saprotrophic nutrition).
• D. Have green leaves → False (no leaves, no chlorophyll).

6. Answer: (3) Bat [2]

Explanation:
Follow the flowchart:

• Does it make its own food? No (bat is animal) → Does it reproduce by spores? No → Does it have feathers? No → Mammal.
• Mushroom → reproduces by spores → Fungi.
• Fern → makes own food → Plant.
• Eagle → has feathers → Bird.
• Bat → mammal (has hair, gives birth to live young, feeds milk).

7. Answer: (4) S [2]

Explanation:
From the table:

• P: Makes own food → Plant
• Q: Makes own food → Plant
• R: Reproduces by spores → Fungi
• S: Has feathers → Bird (only birds have feathers).

Bird characteristics: feathers, beak, lays eggs, wings (mostly), lungs.

8. Answer: (3) Bacteria reproduce by binary fission. [2]

Explanation:

• (1) False: Many bacteria are beneficial (e.g., in digestion, decomposition, yoghurt making).
• (2) False: Bacteria are microscopic; need a microscope to see.
• (3) True: Binary fission is asexual reproduction where one cell splits into two identical cells.
• (4) False: Bacteria do not photosynthesize (except cyanobacteria, but generally taught as not making own food in P4).

9. Answer: (2) Gills [2]

Explanation:

• Spores are produced in the gills (located on the underside of the cap).
• Cap protects gills; stalk supports cap; mycelium absorbs nutrients (hidden in soil).

10. Answer: (2) Frog, lizard, eagle [2]

Explanation:
Vertebrates have a backbone.

• (1) Earthworm, snail, spider → all invertebrates (no backbone).
• (2) Frog (amphibian), lizard (reptile), eagle (bird) → all vertebrates. ✓
• (3) Beetle, butterfly, grasshopper → insects (invertebrates).
• (4) Jellyfish, starfish, octopus → invertebrates.

11. Answer: (3) Group X: Flowering plants; Group Y: Flowering plants [2]

Explanation:

• Rose, hibiscus, bougainvillea → all flowering plants (produce flowers).
• Mango, apple, durian trees → all flowering plants (fruit trees flower before fruiting).
• Non-flowering plants: fern, moss, algae (reproduce by spores).

12. Answer: (2) Larva [2]

Explanation:

• Larva (caterpillar) is the feeding stage — eats leaves voraciously, causing most damage to plants.
• Egg: dormant. Pupa: inactive, no feeding. Adult: feeds on nectar, not leaves.

13. Answer: (2) Fern [2]

Explanation:

• Fern reproduces by spores (on underside of fronds), no flowers → non-flowering plant.
• Balsam, sunflower, morning glory → all produce flowers → flowering plants.

14. Answer: (1) W [2]

Explanation:
Greenhouse roof needs to:

• Allow light to pass through (for photosynthesis) → W and Y.
• Waterproof (keep rain out) → W, X, Z.
• Not flexible (rigid structure) → W, Z.
  Only W satisfies all three: allows light, not flexible, waterproof.

SECTION B: Open-Ended Questions (32 marks)

15. [3]

(a) Both reproduce by spores (fern: spores on fronds; mushroom: spores on gills).
Or: Both are living things / Both grow / Both respond to changes.
Accept any valid similarity. [1]

(b) The bird is an animal (has feathers, breathes with lungs, lays eggs with hard shells), while the fern and mushroom are plants/fungi (fern = plant, mushroom = fungus).
Or: Bird moves from place to place (locomotion), fern and mushroom are stationary.
Or: Bird breathes with lungs, fern and mushroom do not have lungs.
Accept any valid difference. [1]

(c) [1]

Note: Mushroom is a fungus, not a plant. Bird is an animal. Both are non-plants.

16. [4]

(a) C [1]
Reasoning: Mammal that lays eggs → Does it lay eggs? Yes → Does it have feathers? No → C. (This is the platypus/echidna path — monotremes).

(b) A [1]
Reasoning: Bird → Lays eggs? Yes → Has feathers? Yes → A.

(c) Platypus or Echidna (spiny anteater) [1]
These are the only egg-laying mammals (monotremes).

(d) Dog, cat, human, whale, bat, etc. (any placental or marsupial mammal) [1]
Does it lay eggs? No → Has hair? Yes → D.

17. [3]

(a) Flower [1]

(b) Makes food for the plant through photosynthesis (traps light using chlorophyll). [1]

(c) The stem (R) transports water and food between roots and leaves. If cut, water/minerals from roots cannot reach leaves, and food from leaves cannot reach roots → plant dies. [1]

18. [4]

(a) Plant [1]
Reason: It is green (has chlorophyll) and grows on damp soil — typical of non-flowering plants like moss/algae. Fungi are not green (no chlorophyll).

(b) It contains chlorophyll (green) and can make its own food (photosynthesis), whereas fungi cannot make their own food (no chlorophyll, feed on decaying matter). [1]

(c) Moss (or algae, liverwort) [1]
Green, spore-reproducing, non-flowering, damp soil → moss.

(d) Moss does not have flowers / reproduces by spores, while flowering plants produce flowers and seeds.
Or: Moss has no true roots/stems/leaves (has rhizoids, simple structures), flowering plants have true roots, stems, leaves. [1]

19. [4]

(a) Bat [1]
Only mammal: has hair, breathes with lungs, gives birth to live young, feeds young with milk.

(b) Guppy and Snake (both have scales) [1]

(c) Both lay eggs (oviparous). [1]

(d) Bat has hair/fur and gives birth to live young (mammal characteristics); Penguin has feathers and lays eggs (bird characteristics). Wings are not the defining feature — body covering and reproduction method are. [1]

20. [4]

(a) Algae or Liverwort or Moss (any non-flowering plant not already listed) [1]
Chart already has Fern, Moss → accept Algae or Liverwort.

(b) Spider or Snail or Jellyfish or Earthworm (any invertebrate not already listed) [1]
Chart already has Insect, Worm → accept Spider, Snail, Jellyfish, etc.

(c) Produce flowers (and seeds enclosed in fruits) for reproduction. [1]

(d) Have a backbone (vertebral column) / internal skeleton made of bones. [1]

END OF ANSWER KEY