Primary 3 Science Semestral Assessment 2 (End of Year) Paper 4

TuitionGoWhere Practice Paper — Science Primary 3

SA2 Answer Key — Version 4 of 5

Section A: Multiple Choice Questions (10 × 2 marks = 20 marks)

1. (c) A butterfly
Reasoning: A butterfly is an animal and a living thing. A wooden chair, plastic toy car, and metal spoon are non-living things.

2. (b) They can grow.
Reasoning: All living things grow. Not all living things can fly (e.g., plants), are green (e.g., animals), or live on land (e.g., fish).

3. (a) P
Reasoning: Object P shows all three characteristics — it moves by itself, grows, and needs water — which are key traits of living things. Q shows none. R moves but does not grow or need water (likely a toy or machine). S grows and needs water but does not move by itself (likely a plant, but P is the strongest candidate as it shows the most characteristics).

4. (c) A cloud
Reasoning: A cloud is made of water droplets and is non-living. A mushroom is a fungus (living), a goldfish is an animal (living), and a fern is a plant (living).

5. (c) Cars cannot move by themselves without fuel and a driver.
Reasoning: Living things move by themselves. A car requires an external source (fuel and a driver) to move, so it does not meet the criterion of moving independently.

6. (b) Goldfish, eagle, frog
Reasoning: All three are animals. Option (a) includes only plants and fungi. Option (c) lists fungi and bacteria. Option (d) lists only plants.

7. (c) Orchid
Reasoning: An orchid is a flowering plant. Ferns and mosses are non-flowering plants. A mushroom is a fungus, not a plant.

8. (b) A plant growing towards sunlight.
Reasoning: This is a living thing (a plant) responding to a stimulus (light). A rock rolling is caused by gravity (external force), a balloon inflating is caused by air being pumped in (external), and ice melting is a physical change (non-living).

9. (c) They are made of metal.
Reasoning: Being made of metal is not a characteristic of living things. Living things reproduce, need food and water, and respond to changes.

10. (c) Fungi and bacteria
Reasoning: Mushroom, mould, and yeast are fungi. Bacteria are a separate group of microorganisms. Together, they belong to fungi and bacteria — neither plants nor animals.

Section B: True or False (5 × 1 mark = 5 marks)

11. F
Reasoning: A teddy bear may look like it has body parts, but it cannot grow, reproduce, or respond to changes. It is non-living. Having eyes and a nose does not make something alive.

12. T
Reasoning: All living things need air, water, and food to survive. This is one of the key characteristics of living things.

13. T
Reasoning: A fern reproduces by spores and does not produce flowers. It is classified as a non-flowering plant.

14. T
Reasoning: Bacteria are living organisms. They are microscopic and cannot be seen with the naked eye alone, but they grow, reproduce, and need food and water.

15. F
Reasoning: A balloon getting bigger when inflated is due to air being pumped in from outside. This is not biological growth. The balloon does not need food, water, or air to survive, and it cannot reproduce.

Section C: Short Answer Questions (10 marks)

16. (4 marks — 1 mark each)

Marking note: Award 1 mark for each correct classification. A kitten (animal), potted plant (plant), and earthworm (animal) are living things. A wooden ruler (made from wood but no longer alive) is non-living.

17. (2 marks — 1 mark each)

Accept any two of the following:

• They can grow.
• They can reproduce.
• They need water, food, and air to survive.
• They can move by themselves.
• They respond to changes in their surroundings.

Marking note: Award 1 mark for each correct characteristic. Answers must describe a characteristic shared by ALL living things. "They can fly" or "They are green" are incorrect as they do not apply to all living things.

18. (2 marks)

Sample answer: The object might be a living thing that is very small or not moving at the moment, such as a snail resting, a seed, or a tiny insect. Some living things do not move quickly or may appear still.

Marking note: Award 2 marks for a clear explanation that identifies a living thing that could be mistaken for non-living (e.g., a seed, a snail, a small insect, a plant). Award 1 mark for a partially correct answer. Accept any reasonable explanation.

Section D: Structured / Application Questions (15 marks)

19. (7 marks total)

(a) (4 marks — 1 mark per correct row)

Marking note: Award 1 mark for each correctly completed row. A (frog) and D (goldfish) are animals. B (fern) is a plant. C (mushroom) is a fungus.

(b) (1 mark)

Accept any one of the following:

• Both need water to survive.
• Both need food to survive.
• Both can grow.
• Both can reproduce.
• Both respond to changes in their surroundings.

Marking note: Award 1 mark for any valid shared characteristic of living things.

(c) (2 marks)

Sample answer: Yes, the fern is still a plant. It has leaves (fronds), makes its own food through photosynthesis, and needs water and sunlight to grow. Not all plants need flowers to be classified as plants. Ferns are non-flowering plants that reproduce by spores.

Marking note: Award 1 mark for stating "yes" and 1 mark for a valid explanation (e.g., it has leaves/fronds, makes its own food, needs water/sunlight, or reproduces by spores).

20. (8 marks total)

(a) (4 marks — 2 marks per living thing with reason)

Living things in the table:

• Squirrel — It moves by itself, grows over time, needs water, and responds to touch. It shows all characteristics of living things. (2 marks)
• Venus flytrap — It moves by itself (closes when touched), grows over time, needs water, and responds to touch. It is a living plant. (2 marks)
• Mould on bread — It grows over time and needs water. Even though it does not move by itself or respond to touch, it shows some characteristics of living things and is a living organism (fungus). (Accept as living — included in reasoning below)

Marking note: Award 2 marks for each correctly identified living thing with a valid reason. Squirrel and Venus flytrap are the clearest answers. Mould is also living — if students identify it, accept with appropriate reasoning. Award partial marks (1 mark) for identifying a living thing without a reason or with an incomplete reason.

(b) (2 marks)

Sample answer: Mould is still a living thing because it can grow (it spreads over the bread) and it needs water and food (from the bread) to survive. It is a type of fungus. Not all living things need to move or respond to touch to be considered alive.

Marking note: Award 2 marks for mentioning that mould grows and needs water/food, and identifying it as a fungus. Award 1 mark for mentioning only one characteristic.

(c) (2 marks)

Sample answer: The rock is not a living thing. Although it is found in nature, it does not grow, does not need food, water, or air, cannot reproduce, and does not respond to changes. Being found in nature does not make something alive — only things that show the characteristics of living things are classified as living.

Marking note: Award 2 marks for clearly stating the rock is non-living and giving at least two valid reasons (e.g., does not grow, does not need food/water/air, cannot reproduce). Award 1 mark for a partially correct answer.

— End of Answer Key —

Mark Summary