How does a person change from a baby to an elder, and is a bird the same?
Your guess
Pick one before you read on. It is fine to be wrong.
By the end you can
Put the stages of human life in order, from baby to elder
Compare the human life cycle with the life cycle of a bird
Every living thing starts life, grows, and can have young of its own. Then it grows old and dies. These stages, in order, make a life cycle.
Draw it first
Draw the stages of a human life
1 Draw a baby, small with a big head. Next to it, draw a taller child.
2 Draw an adolescent, taller again and growing fast.
3 Draw an adult, who has stopped growing taller.
4 Draw an elder, a little shorter than the adult, with a stick.
A baby feeds on milk and cannot walk. A child learns to walk, talk and do more alone. An adolescent is no longer a child, but not yet an adult. This is when the body changes in puberty.
An adult has stopped growing taller and is old enough to have children. An elder is an adult who has grown old. The body slows down, and it may get a little shorter.
The five stages of a human life, in order.
Look at the heads in the drawing. A baby's head is about a quarter of its length. An adult's head is about an eighth of their height. The legs grow the most. So a body changes shape as it grows, not only size.
The ring goes from adult back to baby, because many adults have children. Each new baby starts the cycle again. Growing old, as an elder, is the last part of one life.
A bird has a life cycle too. A hen lays eggs with a hard shell. If an egg was fertilised, a young bird grows inside it, outside its mother's body. When it is ready, it breaks the shell and comes out. This is called hatching, and the bird that hatches is a chick.
The life cycle of a bird. The adult lays eggs, and the cycle starts again.
See it three ways
As a picture
In words
A human baby grows inside its mother and is born. A chick grows inside an egg, outside its mother, and hatches. Both grow up, and both can have young when they are adult.
In symbols
hen: egg → chick in about 21 days. human: a pregnancy of about 40 weeks.
Try it
Make a life line of your family
You need: paper, a pencil, a ruler or a straight stick.
Draw a long straight line across the paper. Mark five stages along it: baby, child, adolescent, adult, elder.
Think of the people you live with or know well. Decide which stage each person is in.
Write each name under its stage. Put yourself on the line too.
What you will see: Most families have people at several stages. Everyone moves along the same line, one stage after another, at their own speed.
If you cannot try it, this is what happens.
A wrong idea many people have
A baby is just a small adult.
Why it feels right: A baby has the same parts as an adult: a head, arms, legs and a heart.
The test that breaks it: Look at the drawing. The baby's head is a quarter of its length, and the adult's is an eighth. A baby cannot walk, and its body has not been through puberty.
What is true: A body changes shape as it grows. Puberty changes it again, from a child's body to an adult's.
Key words
life cycle
the stages of a life, in order, from the start to having young.
adolescent
a person who is no longer a child but not yet an adult.
elder
an adult who has grown old.
hatches
breaks out of an egg.
Back to your guess
The answer is B: A person goes through stages in order: baby, child, adolescent, adult and elder.
A person goes through five stages in order. The body changes shape as well as size. A bird has stages too, but it starts inside an egg with a shell, outside its mother.
Check yourself
Try each one before you look. A wrong answer tells you where to go next.
Which list puts the stages of human life in order?
See the answer
baby, child, adolescent, adult, elder
Each stage follows the one before. A person is a baby, then a child, then an adolescent, then an adult, then an elder.
If you chose B: You may think adolescent is a younger word. An adolescent comes after a child, when puberty starts. Go to S3.4.1.
If you chose C: Every life starts as a baby. Then come child, adolescent, adult and elder. Go to S3.4.1.
Which stage comes just before adult?
See the answer
Adolescent
The adolescent stage is between child and adult. The body changes in puberty, then the person is an adult.
If you chose A: A child still has to go through puberty first. That happens in the stage between child and adult. Go to S3.4.1.
If you chose B: An elder comes after the adult stage, when an adult grows old. Go to S3.4.1.
In the human life cycle, an arrow goes from adult back to baby. Why?
See the answer
Adults can have babies, and each new baby starts the cycle again.
A life cycle goes on because adults have young. So the ring closes at the adult, with a new baby.
If you chose A: The arrow does not mean the same person. It means a new life: an adult has a baby. Go to S3.4.1.
If you chose C: The elder is a branch off the ring. New babies come from adults having children. Go to S3.4.1.
Where does a chick grow before it hatches?
See the answer
Inside an egg with a shell, outside its mother
A bird lays an egg with a hard shell. The chick grows inside it and then hatches.
If you chose B: A hen lays her egg first. The chick grows inside the egg, outside her body. Go to S3.4.1.
If you chose C: A nest holds the eggs. The chick grows inside an egg until it hatches. Go to S3.4.1.
How is the human life cycle like a bird's?
See the answer
Both grow up in stages, and adults of both have young.
Both go through stages to become adults, and adults have young. That is why both are drawn as a ring.
If you chose A: Only the bird's egg has a shell. A human baby grows inside its mother. Go to S3.4.1.
If you chose B: Human babies feed on milk. Hens do not make milk, so a chick eats food from outside. Go to S3.4.1.
Is a baby's head a bigger part of its body than an adult's head is?
See the answer
Bigger: about a quarter for a baby, and about an eighth for an adult
The head grows less than the rest of the body. So it becomes a smaller part of the height.
If you chose A: A body changes shape as it grows. The legs grow more than the head. Go to S3.4.1.
If you chose C: A baby's head looks small, but it is a big part of its whole length. Go to S3.4.1.
A hen sits on her eggs for about 21 days before they hatch. How many weeks is that?
See the answer
About 3 weeks
A week has 7 days. 21 ÷ 7 = 3.
Keep it
Copy this into your exercise book.
A human life goes baby, child, adolescent, adult, elder. Adults can have children, so the cycle goes on. A chick grows in an egg with a shell, outside its mother, and hatches.
Draw: Draw the human life cycle as a ring of four boxes, with elder as a branch from adult.
