From Real Exams Quiz

Primary 4 Science Life Cycles Quiz

Free P4 Science Life Cycles quiz, Nemo3 Exam version, with questions, answers, and syllabus-aligned 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.

Primary 4 Science From Real Exams Generated by NVIDIA Nemotron 3 Ultra 550B A55B Free Updated 2026-08-17

Back to Subject Browse Free Exam Papers

Questions

Primary 4 Science Quiz - Life Cycles

Name: ___________________________
Class: Primary 4 _______
Date: _______________
Score: _______ / 40

Duration: 45 minutes
Total Marks: 40

Instructions:

Answer all questions.
Write your answers in the spaces provided.
For multiple-choice questions, write the letter (A, B, C, or D) in the brackets provided.
For open-ended questions, write your answers clearly in complete sentences.
Diagrams are not drawn to scale unless stated.

Section A: Multiple-Choice Questions (10 × 1 mark = 10 marks)

For each question, choose the correct answer and write its letter in the brackets provided.

1. Which of the following animals undergoes complete metamorphosis?
A. Grasshopper
B. Cockroach
C. Butterfly
D. Chicken

[ ]

2. The diagram below shows the life cycle of a mosquito.

Diagram for Q1 (P4 Science)

Generated diagram for Q1.

Which stage comes after the larva stage?
A. Egg
B. Pupa
C. Adult
D. Nymph

[ ]

3. Study the life cycle of a frog below.

Diagram for Q3 (P4 Science)

Generated diagram for Q3.

Which statement about the frog's life cycle is correct?
A. The young frog (tadpole) looks like a small adult frog.
B. The tadpole breathes through lungs.
C. The tadpole lives in water and the adult frog lives on land.
D. There are only three stages in the life cycle of a frog.

[ ]

4. The diagram below shows the life cycle of a grasshopper.

Diagram for Q4 (P4 Science)

Generated diagram for Q4.

How many stages are there in the life cycle of a grasshopper?
A. Two
B. Three
C. Four
D. Five

[ ]

5. Which of the following is a similarity between the life cycle of a butterfly and the life cycle of a mosquito?
A. Both have a nymph stage.
B. Both have a pupa stage.
C. Both have three stages.
D. Both young stages live on land.

[ ]

6. The diagram below shows a mealworm beetle life cycle.

Diagram for Q6 (P4 Science)

Generated diagram for Q6.

At which stage does the mealworm beetle stop eating and does not move much?
A. Egg
B. Larva
C. Pupa
D. Adult

[ ]

7. Study the table below.

Animal	Type of Metamorphosis	Number of Stages
Butterfly	Complete	4
Grasshopper	Incomplete	3
Mosquito	Complete	4
Cockroach	Incomplete	3

Based on the table, which animal has the same type of metamorphosis as a butterfly?
A. Grasshopper
B. Mosquito
C. Cockroach
D. Chicken

[ ]

8. The young of a cockroach is called a nymph. How does a nymph become an adult?
A. It spins a cocoon and becomes a pupa.
B. It moults several times, growing larger each time.
C. It lays eggs which hatch into adults.
D. It grows wings suddenly overnight.

[ ]

9. Which of the following statements about incomplete metamorphosis is true?
A. There is a pupa stage.
B. The young (nymph) looks very different from the adult.
C. There are four stages: egg, larva, pupa, adult.
D. The young (nymph) resembles the adult but is smaller and wingless.

[ ]

10. A student observed an insect life cycle. The insect hatched from an egg into a worm-like larva, then became a non-feeding pupa, and finally emerged as a winged adult. This insect most likely undergoes:
A. Incomplete metamorphosis
B. Complete metamorphosis
C. No metamorphosis
D. Partial metamorphosis

[ ]

Section B: Structured Questions (5 × 2 marks = 10 marks)

Answer the following questions in the spaces provided.

11. The diagram below shows the life cycle of a butterfly.

Diagram for Q11 (P4 Science)

Generated diagram for Q11.

(a) Name the stages labelled B and C.
B: _______________________________________
C: _______________________________________

[2]

(b) State one difference between stage B and stage D in terms of how they obtain food.

[1]

12. The diagram below shows the life cycle of a frog.

Diagram for Q12 (P4 Science)

Generated diagram for Q12.

(a) Name the stage labelled Y.

[1]

(b) State one difference in breathing method between stage Y and stage Z.

[1]

13. The diagram below shows the life cycle of a grasshopper.

Diagram for Q13 (P4 Science)

Generated diagram for Q13.

(a) Name the stage labelled Q.

[1]

(b) The nymph moults several times before becoming an adult. Explain why the nymph needs to moult.

[1]

14. Compare the life cycle of a mosquito and a grasshopper.

(a) State one similarity in their life cycles.

[1]

(b) State one difference in their life cycles.

[1]

15. The diagram below shows a chicken's life cycle.

Diagram for Q15 (P4 Science)

Generated diagram for Q15.

(a) How many stages are there in the life cycle of a chicken?

[1]

(b) Does the chicken undergo metamorphosis? Explain your answer.

[1]

Section C: Open-Ended Questions (5 × 4 marks = 20 marks)

Answer the following questions in the spaces provided. Show your reasoning clearly.

16. The diagram below shows the life cycle of a mealworm beetle (darkling beetle).

Diagram for Q16 (P4 Science)

Generated diagram for Q16.

(a) Name the stages labelled 2 and 3.
Stage 2: _______________________________________
Stage 3: _______________________________________

[2]

(b) At which stage (2, 3, or 4) does the beetle stop feeding? Explain why.

[2]

17. Study the two life cycles below.

Diagram for Q17 (P4 Science)

Generated diagram for Q17.

(a) Name the type of metamorphosis for each animal.
Butterfly: _______________________________________
Grasshopper: _______________________________________

[2]

(b) State two differences between the two life cycles.
Difference 1: ________________________________________________________________________
Difference 2: ________________________________________________________________________

[2]

18. A student found an unknown insect in the garden. She observed it for several weeks and recorded the following:

It hatched from an egg into a small wingless insect that looked like a tiny version of the adult.
It moulted 5 times, growing larger each time.
After the final moult, it had fully developed wings and could fly.

(a) Does this insect undergo complete or incomplete metamorphosis?

[1]

(b) Give two reasons from the observations to support your answer in (a).
Reason 1: ________________________________________________________________________
Reason 2: ________________________________________________________________________

[2]

[1]

19. The diagram below shows the life cycle of a mosquito.

Diagram for Q19 (P4 Science)

Generated diagram for Q19.

(a) Name the stages labelled X and Y.
X: _______________________________________
Y: _______________________________________

[2]

(b) Both stages X and Y live in water. State one way in which stage X is different from stage Y in terms of movement.

[1]

20. The table below shows the number of days for each stage in the life cycle of a butterfly at 25°C.

Stage	Number of Days
Egg	4
Larva (Caterpillar)	14
Pupa (Chrysalis)	10
Adult	21 (average lifespan)

(a) How many days does it take for a butterfly egg to develop into an adult butterfly?

[1]

(b) At which stage does the caterpillar stop eating and attach itself to a branch?

[1]

[2]

End of Quiz

Free quiz and exam paper access

Enter your details to view this paper

Your access is remembered on this device.

Answers

Primary 4 Science Quiz - Life Cycles (Answer Key)

Total Marks: 40

Section A: Multiple-Choice Questions (10 × 1 mark = 10 marks)

1. C
Explanation: A butterfly undergoes complete metamorphosis with four stages: egg → larva (caterpillar) → pupa (chrysalis) → adult. Grasshoppers and cockroaches undergo incomplete metamorphosis (egg → nymph → adult). Chickens do not undergo metamorphosis; they grow gradually from chick to adult.

2. B
Explanation: The mosquito life cycle (complete metamorphosis) follows the sequence: Egg → Larva → Pupa → Adult. After the larva (wriggler) stage comes the pupa (tumbler) stage.

3. C
Explanation: Frogs have a life cycle with distinct habitat changes: tadpoles are aquatic (live in water, breathe through gills) while adult frogs are amphibious (live on land and in water, breathe through lungs and skin).

A is incorrect: Tadpoles look very different from adult frogs (no legs, have tail, gills).
B is incorrect: Tadpoles breathe through gills, not lungs.
D is incorrect: Frogs have more than three stages (egg, tadpole, froglet, adult).

4. B
Explanation: Grasshoppers undergo incomplete metamorphosis with three stages: Egg → Nymph → Adult. The nymph resembles a small, wingless adult.

5. B
Explanation: Both butterflies and mosquitoes undergo complete metamorphosis, which includes a pupa stage. Butterflies have a chrysalis; mosquitoes have a tumbler (pupa). Neither has a nymph stage (A is wrong). Both have four stages, not three (C is wrong). Mosquito larvae and pupae live in water (D is wrong).

6. C
Explanation: The pupa stage is a non-feeding, relatively immobile stage where the larva transforms into an adult. The mealworm (larva) eats actively, the adult beetle feeds, but the pupa does not eat or move much.

7. B
Explanation: From the table, both the butterfly and mosquito have "Complete" metamorphosis with 4 stages. Grasshopper and cockroach have incomplete metamorphosis.

8. B
Explanation: In incomplete metamorphosis, the nymph moults (sheds its exoskeleton) several times as it grows. Each moult allows the nymph to increase in size and develop wings gradually. There is no pupa stage (A is wrong). Nymphs don't lay eggs (C is wrong). Wing development is gradual, not sudden (D is wrong).

9. D
Explanation: In incomplete metamorphosis:

There is NO pupa stage (A is false).
The young (nymph) resembles the adult but is smaller and wingless (D is true).
There are three stages: egg, nymph, adult (C is false - that's complete metamorphosis).
The nymph looks similar to the adult, not very different (B is false).

10. B
Explanation: The description (egg → worm-like larva → non-feeding pupa → winged adult) matches complete metamorphosis. Incomplete metamorphosis has no larva or pupa stages.

Section B: Structured Questions (5 × 2 marks = 10 marks)

11.
(a) B: Larva / Caterpillar
C: Pupa / Chrysalis
[1 mark each, total 2 marks]

(b) Stage B (caterpillar) eats leaves by chewing, while Stage D (adult butterfly) feeds on nectar by sucking through a proboscis.
[1 mark]
Acceptable answers: Caterpillar chews solid food (leaves); butterfly sucks liquid food (nectar).

12.
(a) Y: Tadpole
[1 mark]

(b) Stage Y (tadpole) breathes through gills in water, while Stage Z (adult frog) breathes through lungs on land (and also through moist skin).
[1 mark]
Key concept: Change in respiratory organs from gills to lungs during metamorphosis.

13.
(a) Q: Nymph
[1 mark]

(b) The nymph has a hard exoskeleton that does not stretch. To grow larger, it must shed (moult) its old exoskeleton and form a new, larger one.
[1 mark]
Key concept: Arthropods have rigid exoskeletons; growth requires moulting.

14.
(a) Both life cycles begin with an egg stage.
[1 mark]
Other acceptable: Both have an adult stage; both involve growth and development.

(b) Mosquito has a pupa stage (complete metamorphosis, 4 stages) while grasshopper has no pupa stage (incomplete metamorphosis, 3 stages).
[1 mark]
Or: Mosquito young (larva) looks very different from adult; grasshopper young (nymph) resembles adult.
Or: Mosquito larvae live in water; grasshopper nymphs live on land.

15.
(a) Four stages (Egg → Chick → Young Chicken → Adult)
[1 mark]

(b) No, the chicken does not undergo metamorphosis. The young (chick) resembles the adult in body structure and only differs in size, feather covering, and maturity. It grows gradually without distinct larval or pupal stages.
[1 mark]
Key concept: Metamorphosis involves distinct, dramatic changes in form (larva/pupa). Chickens show direct development.

Section C: Open-Ended Questions (5 × 4 marks = 20 marks)

16.
(a) Stage 2: Larva / Mealworm
Stage 3: Pupa
[1 mark each, total 2 marks]

(b) Stage 3 (Pupa). The pupa is a non-feeding, resting stage where the larva's body is reorganised into the adult form. It does not have functional mouthparts for feeding.
[2 marks]
Mark breakdown: 1 mark for identifying Stage 3, 1 mark for correct explanation (non-feeding/resting stage, body reorganisation, no mouthparts).

17.
(a) Butterfly: Complete metamorphosis
Grasshopper: Incomplete metamorphosis
[1 mark each, total 2 marks]

(b) Difference 1: Butterfly has four stages (egg, larva, pupa, adult); grasshopper has three stages (egg, nymph, adult).
Difference 2: Butterfly has a pupa stage; grasshopper has no pupa stage.
[1 mark each, total 2 marks]
Other acceptable differences: Butterfly larva (caterpillar) looks very different from adult; grasshopper nymph resembles adult. Butterfly larva has prolegs; grasshopper nymph has jointed legs like adult. Butterfly pupa is immobile; grasshopper nymph is active.

18.
(a) Incomplete metamorphosis
[1 mark]

(b) Reason 1: The young (nymph) looks like a small, wingless version of the adult (resembles adult).
Reason 2: It moults several times to grow and develop wings gradually, without a pupa stage.
[1 mark each, total 2 marks]
Key evidence from observations: "looked like a tiny version of the adult" and "moulted 5 times... after final moult, had fully developed wings" — no mention of larva or pupa.

19.
(a) X: Larva / Wriggler
Y: Pupa / Tumbler
[1 mark each, total 2 marks]

(b) Stage X (larva/wriggler) moves actively by wriggling/swimming in water, while Stage Y (pupa/tumbler) moves by tumbling/rolling when disturbed but is mostly inactive at the water surface.
[1 mark]
Key concept: Larva is actively feeding and moving; pupa is a transitional, mostly non-feeding stage with limited movement.

(c) Mosquitoes lay their eggs in stagnant water. The larvae and pupae develop in water. Removing stagnant water removes their breeding sites, preventing them from completing their life cycle.
[1 mark]
Application of knowledge: Source reduction is key to mosquito control.

20.
(a) 4 + 14 + 10 = 28 days
[1 mark]
Working: Egg (4 days) + Larva (14 days) + Pupa (10 days) = 28 days to reach adult stage.

(b) Pupa stage (Chrysalis)
[1 mark]
At the end of the larva stage, the caterpillar stops eating, attaches to a branch (or leaf), and forms a chrysalis (pupa).

(c) The caterpillar has a soft body but a relatively inflexible cuticle (skin). As it eats and grows rapidly, its skin becomes too tight. It must moult (shed its old skin) to allow its body to expand and grow larger.
[2 marks]
Mark breakdown: 1 mark for identifying growth/size increase, 1 mark for explaining the constraint of the exoskeleton/cuticle requiring moulting.

Common Mistakes & Marking Notes

Confusing "larva" and "nymph": Larva = worm-like young in complete metamorphosis (caterpillar, maggot, wriggler). Nymph = young resembling adult in incomplete metamorphosis.
Forgetting the pupa stage in complete metamorphosis: Always 4 stages: Egg, Larva, Pupa, Adult.
Thinking frogs have "incomplete metamorphosis": Frogs have a unique amphibian metamorphosis (not classified as complete/incomplete like insects). Tadpole → Frog involves dramatic change.
Chicken life cycle: No metamorphosis. Gradual growth only.
Moulting reason: Must mention rigid exoskeleton/cuticle that doesn't stretch.
Mosquito breeding: Stagnant water needed for egg, larva, pupa stages — all aquatic.
Reading diagrams: Pay attention to labels, arrows, and stage characteristics (wings, legs, habitat, feeding).
Calculation questions: Show working (e.g., 4+14+10=28).
Comparison questions: State the feature for BOTH animals (e.g., "Butterfly has pupa; grasshopper has no pupa").
Command words: "State" = short answer; "Explain" = give reason; "Compare" = give similarity AND difference.

Total: 40 marks