Primary 3 Science Life Cycles Quiz

Primary 3 Science Quiz - Life Cycles

Answer Key

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

1. (c) A butterfly

• A butterfly is a living thing that goes through a life cycle (egg → caterpillar → pupa → adult). Plastic toys, wooden chairs, and rubber balls are non-living things.

2. (a) Egg → Chick → Adult chicken

• The life cycle of a chicken begins with an egg. The egg hatches into a chick, which grows into an adult chicken.

3. (b) Pupa

• The life cycle of a butterfly is: Egg → Caterpillar (larva) → Pupa → Adult butterfly. The stage after caterpillar is pupa.

4. (d) plastic

• A seed needs water, air, and sunlight to grow. Plastic is not needed for seed growth.

5. (b) Frog

• A frog's life cycle includes a tadpole stage. The life cycles of grasshoppers, chickens, and lizards do not include a tadpole stage.

6. (c) Caterpillar

• The young of a butterfly is called a caterpillar (also known as a larva). A chick is the young of a chicken. A nymph is the young of a grasshopper. A tadpole is the young of a frog.

7. (c) Pupa

• The life cycle of a flowering plant includes seed, seedling, and adult plant. "Pupa" is a stage in the life cycle of a butterfly, not a plant.

8. (c) Pupa stage

• During the pupa stage, the caterpillar forms a hard casing (chrysalis) around itself. Inside, it changes into an adult butterfly.

9. (c) Cat

• Cats are mammals and give birth to live young. Hens, frogs, and grasshoppers all lay eggs.

10. (b) It begins to grow into a seedling.

• When a seed germinates, it begins to grow roots and a shoot, becoming a seedling.

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

11. True

• All living things go through a life cycle that includes birth, growth, reproduction, and death.

12. False

• A caterpillar is the young of a butterfly, not a grasshopper. The young of a grasshopper is called a nymph.

13. True

• Frogs lay their eggs in water. The eggs hatch into tadpoles, which live in water.

14. True

• A seedling is a young plant that has just started to grow from a seed. It has a root, a stem, and small leaves.

15. False

• The life cycle of a grasshopper does NOT include a pupa stage. It goes: Egg → Nymph → Adult grasshopper. Only insects like butterflies have a pupa stage.

Section C: Fill in the Blanks (2 marks each × 3 = 6 marks)

16. The life cycle of a butterfly begins as an egg. It then becomes a caterpillar, then a pupa, and finally an adult butterfly.

• (1 mark for each correct pair: egg + caterpillar = 1 mark; pupa + adult = 1 mark)

17. A frog's egg hatches into a tadpole. It slowly grows legs and loses its tail to become an adult frog.

• (1 mark each)

18. A seed germinates and grows into a seedling. With water, air, and sunlight, it grows into an adult plant.

• (1 mark each)

Section D: Structured Questions

19. (4 marks total)

(a) Stage B is the caterpillar (larva). (1 mark)

(b) During Stage C (the pupa stage), the caterpillar forms a hard casing (chrysalis) around itself. Inside the chrysalis, the caterpillar changes its body structure and develops wings, eventually becoming an adult butterfly. (2 marks)

• (1 mark for mentioning the hard casing/chrysalis; 1 mark for describing the change/transformation)

(c) It is important that the adult butterfly lays eggs because this is how the butterfly reproduces and ensures that new butterflies are born, continuing the life cycle. Without eggs, there would be no new butterflies. (1 mark)

• (Accept any valid answer about reproduction or continuing the life cycle)

20. (4 marks total)

(a) The nymph stage (Stage 2) looks most like the adult grasshopper, as it already has a similar body shape but is smaller and does not have wings yet. (1 mark)

• (Accept "young grasshopper" as well)

(b) The life cycle of a grasshopper is different from the life cycle of a chicken because the grasshopper does NOT have a pupa stage, while the chicken hatches from an egg as a chick that looks like a small chicken. (Accept any one valid difference.) (2 marks)

• (1 mark for identifying a correct difference; 1 mark for clear explanation)
• Alternative answer: A chicken hatches as a chick that looks like a small chicken, but a grasshopper hatches as a nymph that also looks like a small grasshopper but without wings.

(c) We can conclude that both chickens and grasshoppers are animals that lay eggs / begin their life cycles as eggs. (1 mark)

• (Accept any valid conclusion about both being egg-laying animals)

Mark Summary

Common Mistakes to Watch For

• Q3: Students may confuse the order of pupa and adult butterfly. Remind them: caterpillar → pupa → adult.
• Q7: Students may not know that "pupa" is not a plant stage. Reinforce that pupa belongs to insect life cycles.
• Q12: Students often confuse caterpillar (butterfly) with nymph (grasshopper). Clarify the correct young form for each animal.
• Q15: Students may think all insects have a pupa stage. Explain that butterflies and moths have a pupa stage, but grasshoppers and cockroaches do not.
• Q19(b): Students may only state "it changes" without describing what happens inside the chrysalis. Encourage detail.