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Year 3 Science Biological Sciences

Life Cycles

Every living thing goes through stages as it grows. Let's explore life cycles of plants, butterflies, and frogs!

What Is a Life Cycle?

A life cycle is the series of stages a living thing goes through from the beginning of its life to the end. Then the cycle starts again with a new generation!

Life cycles are circular — they go round and round. The end of one cycle is the beginning of the next.

🌱 Plant Life Cycle

Plants start as tiny seeds and grow into full plants that make new seeds. Here are the stages:

🌲

1. Seed

🌱

2. Seedling

🌳

3. Adult Plant

🌸

4. Flower

🍎

5. Fruit/Seeds

🔄 The cycle repeats when new seeds fall to the ground!

1.Seed: A tiny package containing a baby plant and food.
2.Seedling: The seed sprouts roots and a small stem pushes up.
3.Adult Plant: The plant grows leaves and becomes full size.
4.Flower: The plant blooms. Flowers help make new seeds.
5.Fruit & Seeds: Seeds develop inside fruit. They spread and grow new plants.

🦋 Butterfly Life Cycle (Metamorphosis)

A butterfly goes through an amazing change called metamorphosis. It looks completely different at each stage!

🫖

1. Egg

Laid on a leaf

🐛

2. Caterpillar

Eats and grows

🪻

3. Chrysalis

Transforms inside

🦋

4. Butterfly

Flies and lays eggs

🔄 The butterfly lays eggs and the cycle starts again!

🐸 Frog Life Cycle

Frogs also go through metamorphosis. They start in water and later live on land!

1. Eggs

Frogspawn in water

🐠

2. Tadpole

Has a tail, swims

🐸

3. Froglet

Grows legs, loses tail

🐸

4. Adult Frog

Lives on land and water

🔄 The adult frog lays eggs in water and the cycle starts again!

💡 Think About It!

How is the butterfly life cycle similar to the frog life cycle? How are they different? What makes you say that?

🧪 Try It at Home!

Grow a Bean Plant

Watch a complete plant life cycle right at home!

  1. Get a dried bean (kidney bean or broad bean works well)
  2. Soak it in water overnight
  3. Place it on wet cotton wool in a clear jar or cup
  4. Keep the cotton wool moist and put it near a window
  5. Watch every day and draw what you see in a journal
  6. After it sprouts, plant it in soil and watch it grow!

You are seeing the first stages of a plant life cycle: seed to seedling to plant!

Key Vocabulary

Life Cycle

The stages a living thing goes through from birth to death, repeating with new offspring.

Metamorphosis

A big change in body shape as an animal grows, like a caterpillar becoming a butterfly.

Chrysalis

The protective shell around a caterpillar while it transforms into a butterfly.

Germinate

When a seed starts to sprout and grow into a new plant.

Knowledge Check

Choose the correct answer for each question. Click "Check Answer" to see if you are right!

Question 1

What is the correct order for a butterfly life cycle?

Question 2

What is a tadpole?

Question 3

What does a seed need to germinate (start growing)?

Question 4

What is "metamorphosis"?

Question 5

Why is a life cycle called a "cycle"?

Key Concepts Summary

Year 3: Heat Energy Year 4: Earth Changes