Everything changes as it grows
All living things go through stages as they grow. These stages make a life cycle. It’s called a cycle because it goes around and around: the adult makes young, the young grow up, and they make young of their own.
A butterfly’s life cycle
Butterflies change a lot as they grow. This big change is called metamorphosis.
| Stage | What happens |
|---|---|
| 1. Egg | A butterfly lays tiny eggs on a leaf. |
| 2. Larva (caterpillar) | A caterpillar hatches and eats and eats and grows. |
| 3. Pupa (chrysalis) | The caterpillar makes a hard case. Inside, its body changes. |
| 4. Adult | A butterfly comes out, dries its wings and flies away. |
Then the adult butterfly lays eggs, and the cycle starts again.
A frog’s life cycle
| Stage | What happens |
|---|---|
| 1. Egg | A frog lays jelly-covered eggs in water. |
| 2. Tadpole | A tadpole hatches. It has a tail and gills and lives in water. |
| 3. Froglet | It grows legs, and its tail gets shorter. |
| 4. Adult frog | It breathes air with lungs and can live on land and in water. |
A plant’s life cycle
| Stage | What happens |
|---|---|
| 1. Seed | A seed is planted in soil. |
| 2. Sprout | Roots grow down and a tiny shoot grows up. |
| 3. Young plant | It grows more leaves and a stronger stem. |
| 4. Adult plant | It grows flowers. |
| 5. New seeds | The flowers make seeds, which can grow into new plants. |
Animals that look like their parents
Not all animals change shape. A puppy looks like a small dog. A baby elephant looks like a small elephant. These animals are born alive and simply grow bigger.
| Animal | Baby name |
|---|---|
| Dog | Puppy |
| Cat | Kitten |
| Cow | Calf |
| Horse | Foal |
| Sheep | Lamb |
| Kangaroo | Joey |
Offspring look like their parents
The young of a living thing are its offspring. Offspring are like their parents in many ways. Kittens grow into cats, not dogs. An apple seed grows into an apple tree, not a pine tree.
But offspring are not exactly the same as their parents. Puppies in the same litter can have different colours and spots.
In the real world
Farmers know the life cycle of their crops, so they plant seeds at the right time of year. Many schools raise butterflies or tadpoles so students can watch life cycles up close.
Common mistakes
- Thinking a caterpillar is a different animal. It’s a young butterfly.
- Thinking a tadpole is a fish. It’s a young frog.
Try it yourself
- Draw the four stages of a butterfly’s life cycle in a circle, with arrows.
- Plant a bean seed in a clear cup so you can watch the roots grow.
- Match baby animals to their parents: chick, calf, kitten, tadpole.
Quick recap
- A life cycle is the stages a living thing goes through as it grows.
- Butterflies go egg → larva → pupa → adult.
- Frogs go egg → tadpole → froglet → adult.
- Plants go seed → sprout → plant → flower → seeds.
- Offspring are like their parents, but not exactly the same.