Primary 6 · Science · Cycles: Life Cycles
Cycles: Life Cycles questions for Primary 6 Science
8 questions to work through online, 2 of them written out the way the paper asks. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.
- Reading a life cycle
- Choosing where to intervene
- Comparing cycle types
- Reasoning about mosquito control
- Comparing durations
- Frog and butterfly compared
- Naming a stage
| Stage | Where it lives | Does it damage the crop? |
|---|---|---|
| egg | on leaf undersides | ✗ |
| larva | in the soil, on roots | ✓ |
| pupa | in the soil | ✗ |
| adult | flying above the crop | ✗ |
| Stage | Insect A (days) | Insect B (days) |
|---|---|---|
| egg | 3 | 5 |
| larva or nymph | 14 | 25 |
| pupa | 7 | none |
| adult | 30 | 20 |
Answers and explanations for all 8 questions
Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.
According to the diagram above, which stage comes immediately before the adult?
Answer: pupa
The order is egg, larva, pupa, adult, so the pupa is the stage before the adult.
Based on the table above, which stage would be easiest for a farmer to attack?
Answer: the eggs, which are on the leaf undersides
The stage doing the damage is not always the stage to attack. The eggs sit on the leaves where they can be reached, and destroying them prevents the larvae entirely.
Which of these are true of a four-stage life cycle but not a three-stage one?
Answer: A, B and C only
The pupa, the completely different young, and the different diets all belong to four-stage cycles. Starting from an egg is common to both.
Why does a health officer inspect flower pot saucers and blocked gutters rather than spraying for adult mosquitoes?
Answer: The first three stages need standing water, so removing it prevents new adults entirely.
Egg, larva and pupa all develop in standing water. Removing it breaks the cycle before any adult exists, which is more effective than killing adults one at a time.
Based on the table above, which statement is correct?
Answer: Insect A reaches adulthood sooner than insect B.
A takes 3 + 14 + 7 = 24 days to reach adulthood; B takes 5 + 25 = 30 days. A gets there first despite having an extra stage.
Which two statements apply to both a frog's and a butterfly's life cycle?
Answer: A and B only
Both start as eggs and both have young that look nothing like the adult. The pupa belongs to the butterfly and the watery young to the frog.
In the diagram above, the stage between the larva and the adult is spent inside a case without feeding. What is this stage called?
Answer: pupa
The enclosed non-feeding stage between larva and adult is the pupa.
In a three-stage life cycle, the young resembles a small wingless adult and moults as it grows. What is this stage called?
Answer: nymph
The young in a three-stage life cycle is a nymph.