The Life Cycle
of Humans and
Animals
What's the difference between you and newborn babies?
What can you do that they can't?
What do you still need to learn?
Today we'll learn about
- what "life cycle" means
- the life cycle of humans
- common life cycle stages in animals
- interesting animal life cycles
What is a life cycle?
A life cycle is how living things grow and change during different stages of their life.
It includes reproduction, or how living things in the adult stage produce more of their kind.
All animal life cycles have the same four stages.
birth
born as an egg or a live young
growth
continues to grow and learn skills (like moving and communicating)
adolescence
also called juvenile; experiences bodily changes due to hormones
adulthood
fully grown for reproduction
Can you match
these stages to
human life cycle?
birth
growth
adolescence
adulthood
baby
adults
toddler
teenager
child
The Human Life Cycle
You are now at this stage!
birth
baby
child
growth
toddler
adolescence
teenager
adulthood
adults
The "cycle" in life cycle
It means that stages go back to the start and repeat.
Adults can take part
in reproduction to produce a baby—and the cycle starts again!
baby
toddler
child
Reproduction
adults
teenager
Fact Break
These animals can live more than a hundred years! Can you name them?
Lifespan varies in length.
The life cycle includes a living thing's lifespan or the time between birth and death.
The mayfly can live for only 24 hours, while a dragonfly has a lifespan of up to three months.
What about the life cycle of animals?
Are they all born the same way?
What stages do we have in common?
Some animals hatch from eggs.
This adds another stage to a life cycle. Some animals have more than others.
Butterfly
Frog
Which stages look similar?
Which are different?
Butterfly
eggs
larva
pupa
adult
Frog
eggs
tadpole
tadpole with legs
froglet
adult
Strange Stages
Some animal life cycles have uncommon stages.
It lays eggs (like birds) but still has fur and feeds its baby with milk like any other mammal.
Duck-billed Platypus
Strange Stages
Some animal life cycles have uncommon stages.
Kangaroo
It gives birth to a not yet fully formed baby called "joey," born the size of a jellybean. A joey continues to grow in its mother's pouch.
Let's Review
There are common stages in all animal life cycles.
This includes birth, growth, adolescence, and adulthood.
Animals and humans have similar and different stages.
Humans and other animals are born as babies (called live young), but other animals start out as eggs.
Think about it
Choose a baby animal and compare it to when you were a baby.
How are you the same and different?