What Is a Life Cycle? From Egg to Grown-Up

What You'll Learn

• Different organisms can have different stages, but life cycles repeat when adults make offspring
• A butterfly's life cycle is egg, larva or caterpillar, pupa or chrysalis, and adult
• A frog's life cycle is egg, tadpole, froglet, and adult frog
• Life cycles are loops, not one-way lines, because the cycle starts again with a new generation

Words to Know

Life cycle

The repeating stages of a living thing's life

A butterfly life cycle starts with an egg.

Larva

A young animal stage that looks different from the adult

A caterpillar is the larva stage of a butterfly.

Pupa

The stage when a caterpillar changes inside a chrysalis

The butterfly changes during the pupa stage.

Tadpole

A young frog that lives in water and has a tail

The tadpole grows legs before it becomes a froglet.

Offspring

A baby living thing made by its parents

Adult frogs lay eggs that become offspring.

Check What You Learned

Fun Facts

• NGSS 3-LS1-1 says organisms have unique and diverse life cycles, but all life cycles share birth, growth, reproduction, and death.

  Source: Next Generation Science Standards, 3-LS1-1

• A butterfly's life cycle has four main stages: egg, larva, pupa, and adult.

  Source: American Museum of Natural History, "The Life Cycle of a Butterfly"

• Butterfly larvae are caterpillars, and the pupa stage happens inside a chrysalis where the butterfly changes form.

  Source: American Museum of Natural History, "The Life Cycle of a Butterfly"

• Adult butterflies produce eggs, which begins the life cycle again.

  Source: American Museum of Natural History, "The Life Cycle of a Butterfly"

• A frog life cycle can be described in four kid-friendly stages: egg, tadpole, froglet, and adult frog.

  Source: Australian Museum, "Interactive: Frog life cycle, from egg to adult"

• Tadpoles live in water and have tails, then they grow legs and become froglets before becoming adult frogs.

  Source: Australian Museum, "Interactive: Frog life cycle, from egg to adult"