Pick one before you read on. It is fine to be wrong.
By the end you can
Describe the body changes of puberty in girls and in boys
Explain that puberty starts at different times for different people
Puberty is the time when a child's body changes into an adult's body. It happens in the adolescent stage. It takes a few years from start to end.
Puberty starts with hormones. A hormone is a chemical messenger. It is made in one part of the body and carried in the blood to other parts. There it tells them to change.
Draw it first
Draw the changes that come to everyone
1 Draw a person standing. In puberty the bones grow fast: a growth spurt.
2 Hair grows under the arms and on the pubic area, just above the genitals.
3 You sweat more, and many people get spots on the face.
Some changes come to everyone. You grow fast for a while. This is a growth spurt. Hair grows under the arms. It also grows on the pubic area, the skin just above the genitals. The genitals are the sex organs on the outside of the body.
You sweat more, and sweat can start to smell. Many people get spots on the face and back. These spots are called acne. Your feelings change too. The next chapter is about feelings.
Changes for girls. The breasts grow and the hips get wider. Periods start. A later chapter explains periods.Changes for boys. The testes and the penis grow, the voice gets deeper, and hair grows on the face. The shoulders get wider.
Boys start to have erections. An erection is when the penis fills with blood and gets stiff for a while. It can happen for no reason at all. Some boys have wet dreams. Semen is a fluid with sperm in it. A wet dream is when semen comes out of the penis during sleep. Both are a normal part of growing up.
Some changes can look worrying, but they are normal. Breast buds can feel tender, and one breast often grows faster than the other. Many boys' chests swell a little for a while, then flatten again. One testis usually hangs lower than the other. A boy's voice may crack, jumping high and low, before it settles deeper.
From puberty, girls may find a little clear or white fluid in their underwear. It is called discharge. It comes from the vagina and keeps it clean, and it is normal.
Many people touch their own genitals in private. This is common and normal, and it does no harm to the body. It is a private matter, and nobody should make you feel ashamed of your body. A child's genitals are private. No older person may touch them. A health worker who explains why and asks first is different. So is a carer washing a baby. Chapter 8 says what to do if someone does.
A few people are born with a body that is not the usual female or male pattern. Sometimes it is only the parts inside. This is a natural difference. A health worker can explain it.
Puberty starts at different times for different people. It can start some years earlier or later than for a friend. There is no right time. Each body has its own timetable.
Doctors know the usual spans. In girls, the breasts usually start to grow between about 8 and 13 years. The first period most often comes between about 10 and 15 years. In boys, the testes usually start to grow between about 9 and 14 years. So for many girls puberty starts a little earlier than for boys.
The usual spans, from medicine. They are wide on purpose: anywhere inside them is normal.
The changes then take a few years. Most girls have finished by about 14 to 16 years. Most boys have finished by about 16 to 18 years. Anywhere inside these wide spans is normal.
Four friends in one class. All four are normal. Kofi's changes will come on his own timetable.
See it three ways
With things
Mei marked her height on a door frame every half year. In the middle of puberty the marks moved apart faster.
As a picture
In words
For a while, Mei grew twice as fast. That is her growth spurt. Then her growth slowed down again.
In symbols
148 cm − 144 cm = 4 cm
Try it
Measure your height on a door frame
You need: a door frame, a pencil, a flat book, a tape measure, or a string and a ruler.
Stand straight with your back to the door frame, with no shoes on. Ask someone at home to lay a book flat on your head and mark under it.
Measure from the floor to the mark. Write the height and the date beside it.
Do it again every few months, on the same frame. Work out how much you grew each time.
What you will see: Over time the marks move apart. In a growth spurt they move apart faster.
If you cannot try it, this is what happens.
A wrong idea many people have
If my body has not changed yet, something is wrong with me.
Why it feels right: Friends of the same class may already look older, and it is natural to compare.
The test that breaks it: Ask any adults you trust when their own changes came. Their answers will be spread out, some early and some late.
What is true: Puberty starts at different times for different people. Starting later, or earlier, is normal.
Key words
puberty
the time when a child's body changes into an adult's body.
hormones
chemical messengers, carried in the blood, that tell parts of the body to change.
growth spurt
a time of growing much faster than before.
genitals
the sex organs on the outside of the body.
erections
times when the penis fills with blood and gets stiff.
wet dreams
times when semen comes out of the penis during sleep.
Back to your guess
The answer is C: Puberty is a time of body changes, and it starts at different times for different people.
Puberty changes a child's body into an adult's. It comes to everyone, girls and boys, but each body starts on its own timetable.
Check yourself
Try each one before you look. A wrong answer tells you where to go next.
Which changes happen to girls in puberty?
See the answer
The breasts grow, the hips widen and periods start
Hormones from the ovaries make the breasts grow, the hips widen and periods start.
If you chose B: Those are changes for boys. Girls' voices change only a little. Go to S3.4.2.
If you chose C: Puberty happens in the adolescent stage, before adult life. Go to S3.4.2.
Which changes happen to boys in puberty?
See the answer
The testes and penis grow, and the voice deepens
Hormones from the testes make the genitals grow, the voice deepen and hair grow on the face.
If you chose A: Periods come from the uterus, and boys do not have one. Go to S3.4.2.
If you chose C: Boys have a growth spurt in puberty. They grow faster for a while. Go to S3.4.2.
Which changes come to both girls and boys?
See the answer
Hair under the arms and on the pubic area, more sweat, and a growth spurt
These changes come to everyone in puberty.
If you chose A: Those are changes for girls. Go to S3.4.2.
If you chose B: Wet dreams are for boys. Semen is made by the male system. Go to S3.4.2.
Joseph's friends' voices have changed, but his has not. What does this mean?
See the answer
Puberty starts at different times. Joseph's body will change on its own timetable.
Puberty can start some years earlier or later than for a friend. Both are normal.
If you chose A: There is no right time. Puberty starts at different times for different people. Go to S3.4.2.
If you chose C: Puberty comes to almost everyone, sometimes later. If it is very late, a health worker can check and help. Go to S3.4.2.
What starts the changes of puberty?
See the answer
Hormones, chemical messengers carried in the blood
Hormones carry the message to change round the body in the blood.
If you chose A: Food gives you energy to grow, but it does not start puberty. Hormones do. Go to S3.4.2.
If you chose B: Sport is good for you, but it does not start puberty. Hormones do. Go to S3.4.2.
Ravi wakes up and finds a little sticky fluid in his bed. It came from his penis while he slept. What is it?
See the answer
A wet dream. It is normal in puberty.
Semen can come out of the penis during sleep. This is a wet dream, and it is normal.
If you chose B: A wet dream is not an illness. It is a normal part of puberty, and nothing to hide or be ashamed of. Go to S3.4.2.
If you chose C: Urine is watery. Semen is a thicker fluid with sperm in it. A wet dream is semen. Go to S3.4.2.
Mei's height mark was at 144 cm. Half a year later it was at 148 cm. How much did she grow?
See the answer
4 cm
Take the first height from the second. 148 − 144 = 4.
From an earlier chapter
Which stage of life is puberty part of?
See the answer
Adolescent
The adolescent stage is between child and adult. Puberty happens in it.
If you chose A: A baby is far from puberty. It still feeds on milk. Go to S3.4.1.
If you chose C: An elder went through puberty long ago, as an adolescent. Go to S3.4.1.
Keep it
Copy this into your exercise book.
Hormones start puberty. Girls: breasts grow, hips widen, periods start. Boys: testes and penis grow, voice deepens, face hair. Everyone: body hair, sweat, spots, a growth spurt. It starts at different times. No time is wrong.
Draw: Draw a person and label three changes that come to everyone.
