Life Cycles: Butterflies and Frogs
- Biology
- Ages 8–11 · Grades 3–5
What you’ll find out
- Every living thing has a life cycle: it begins life, grows, reproduces and dies.
- A butterfly passes through four stages: egg, caterpillar (larva), chrysalis and adult.
- A frog passes from frogspawn to tadpole to frog, changing from gills to lungs.
No sign-up and no real names. In the lesson you check your understanding as you read, and practise until it sticks.
A butterfly’s four stages
Every living thing has a life cycle: it begins life, grows, makes young of its own, and in the end dies. A butterfly’s life cycle has four stages. It starts as a tiny egg stuck to a leaf. A caterpillar hatches out and spends its days eating, growing bigger and bigger. Next it forms a hard case called a chrysalis, and inside, its whole body changes shape. Finally a butterfly climbs out, spreads its wings, and later lays eggs of its own, so the cycle begins again.
A frog changes too
A frog has a very different life cycle. A mother frog lays hundreds of eggs in a pond, wrapped in soft jelly called frogspawn. Each egg hatches into a tadpole, which lives underwater, swims with its tail, and breathes through gills, just like a fish. Over several weeks the tadpole grows back legs and then front legs, while its tail slowly shrinks. It also grows lungs so it can breathe air. At last a small frog hops out of the water onto land.
Curriculum links: NGSS 3-LS1-1 · England KS2: Living things and their habitats · Cambridge Primary Stages 4–6: Biology · NCERT Environmental Studies, Classes 3–5