A life cycle is the series of stages through which a living organism passes from birth to growth, reproduction, and death. Every plant and animal has a life cycle, but the number of stages and the type of changes involved can be very different. Some organisms look almost the same throughout their lives, while others undergo dramatic changes in body shape, structure, and habitat as they grow.
In many animals, especially insects and amphibians, these changes are known as metamorphosis. Metamorphosis is a biological process in which an organism develops from an immature form into an adult form that looks and functions very differently. Life cycles help us understand growth, development, adaptation, and survival in nature.
Two classic and commonly studied examples of life cycles are the frog and the butterfly.
- The frog shows metamorphosis and lives in both water and land during different stages.
- The butterfly shows complete metamorphosis and passes through four clearly distinct stages.
This article is a complete, student-friendly guide that explains:
- What a life cycle is
- Meaning of growth, development, and metamorphosis
- Life cycle of a frog (step-by-step)
- Life cycle of a butterfly (step-by-step)
- Differences between frog and butterfly life cycles
- Importance of life cycles in nature
What Is a Life Cycle?
A life cycle is the sequence of changes an organism goes through during its lifetime.
Key Features of a Life Cycle
- Begins with birth or hatching
- Includes growth and development
- Ends with reproduction and death
- Repeats across generations
Growth vs Development
Growth: Increase in size and number of cellsLife cycles include both growth and development.
What Is Metamorphosis?
Metamorphosis is the process in which an organism undergoes major structural changes during its life cycle.
Examples
- Tadpole → Frog
- Caterpillar → Butterfly
Life Cycle of a Frog (Metamorphosis)
The frog life cycle occurs in water and on land and involves several stages.
Stage 1: Eggs (in Water)
- Adult frog lays eggs in water
- Eggs are covered with a jelly-like substance
- Eggs protect the developing embryo
Stage 2: Tadpole
- Tadpole hatches from the egg
- Lives only in water
- Breathes using gills
- Has a long tail and no legs
Stage 3: Tadpole with Legs
- Hind legs appear first
- Lungs start developing
- Tail becomes shorter
- Begins breathing air
Stage 4: Froglet
- Both front and hind legs present
- Tail almost disappears
- Can live on land and water
Stage 5: Adult Frog
- Fully developed frog
- No tail
- Breathes using lungs and skin
- Can reproduce and restart the life cycle
Key Points of Frog Life Cycle
- Shows metamorphosis
- Lives in water and land
- Body shape changes completely
- Multiple stages
Life Cycle of a Butterfly (Complete Metamorphosis)
The butterfly life cycle shows complete metamorphosis with four distinct stages.
Stage 1: Egg (on Leaf)
- Female butterfly lays eggs on leaves
- Eggs hatch after a few days
Stage 2: Larva (Caterpillar)
- Caterpillar emerges from egg
- Eats leaves continuously
- Grows rapidly
- Focused mainly on feeding
Stage 3: Pupa (Chrysalis)
- Caterpillar forms a protective covering
- Inside the pupa, body changes completely
- Wings, legs, and antennae develop
Stage 4: Adult Butterfly
- Fully formed butterfly emerges
- Has wings and can fly
- Feeds on nectar
- Reproduces and lays eggs
Why Is It Called Complete Metamorphosis?
It is called complete metamorphosis because:
- Larva looks completely different from adult
- A resting stage (pupa) is present
- Body structure changes fully
Key Points of Butterfly Life Cycle
- Four clear stages
- Complete metamorphosis
- Lives on land and in air
- Each stage has a specific role
Difference Between Frog and Butterfly Life Cycles
| Feature | Frog | Butterfly |
|---|---|---|
| Type | Metamorphosis | Complete metamorphosis |
| Number of stages | Many | Four |
| Habitat | Water + Land | Land + Air |
| Larval stage | Tadpole | Caterpillar |
| Pupa stage | Absent | Present |
Importance of Life Cycles
Life cycles help organisms to:
- Grow and develop properly
- Adapt to different environments
- Reduce competition between young and adults
- Ensure survival of the species
Life Cycles and Environment
- Different stages use different habitats
- Helps balance ecosystems
- Prevents overcrowding
Common Exam Keywords
- Life cycle
- Metamorphosis
- Tadpole
- Caterpillar
- Pupa / Chrysalis
- Development
FAQs – Life Cycles
1. What is a life cycle?
The stages an organism passes through during its lifetime.
2. What is metamorphosis?
A process involving major body changes during development.
3. Which animal lives in water and land during its life cycle?
Frog.
4. What is the larval stage of a butterfly called?
Caterpillar.
5. What is the pupa stage called in butterflies?
Chrysalis.
6. How many stages are in a butterfly life cycle?
Four.
7. Do frogs have a pupa stage?
No.
8. Why are life cycles important?
They help in growth, development, and survival.
9. What stage eats the most food in a butterfly life cycle?
Larva (caterpillar).
10. Does the life cycle repeat?
Yes, across generations.
