Reproduction
Lesson 4
W.A.L.T
To learn about how a
baby develops
during pregnancy.
WILF
By the end of the lesson I would like you to be able to:
•Describe what happens to an egg cell immediately after it
has been fertilised with a sperm cell.
•Be able to organise pictures of the developing embryo
into chronological order.
•State the function of the placenta.
Listen out for these words during the lesson:
zygote
embryo
foetus
divide
implantation
growth
development
placenta
pregnancy
W.A.L.T
To learn about how a
baby develops
during pregnancy.
The Developing Baby
Here is what a developing embryo looks
like over the first 12 weeks of pregnancy.
Time after
fertilisation
30 Hours
This is a zygote. It has only just been
through fertilisation and has divided once.
The Developing Baby
Here is what a developing embryo looks
like over the first 12 weeks of pregnancy.
Time after
fertilisation
5 Weeks
It is now the size of a raisin. The brain
and spinal chord are starting to develop.
The Developing Baby
Here is what a developing embryo looks
like over the first 12 weeks of pregnancy.
Time after
fertilisation
6 Weeks
A heart has started to beat. Arms and
legs start to form.
The Developing Baby
Here is what a developing embryo looks
like over the first 12 weeks of pregnancy.
Time after
fertilisation
8 Weeks
It is now called a foetus (Latin for young
one). It is producing it’s own stomach
digestive juices.
The Developing Baby
Here is what a developing embryo looks
like over the first 12 weeks of pregnancy.
Time after
fertilisation
9 Weeks
Fingerprints are now formed and it will
grip objects placed in its hand.
Early Signs of Pregnancy
The baby has reached 3 months old. It
has finished most of its developing and
now needs to get a lot bigger.
The mother will not yet have a bump. The baby is
still only as big as an adult thumb and weighs the
same as a one pound coin.
She will however have several signs that she is
pregnant. These include:
Morning
sickness
Food
cravings
Feeling
very tired
Change of
senses
Periods
stop
Question 1
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
What are some of the signs that a woman may
notice to make her think that she is pregnant?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 1
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
What are some of the signs that a woman may
notice to make her think that she is pregnant?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 1
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
What are some of the signs that a woman may
notice to make her think that she is pregnant?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 1
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
What are some of the signs that a woman may
notice to make her think that she is pregnant?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 1
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
What are some of the signs that a woman may
notice to make her think that she is pregnant?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 1
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
What are some of the signs that a woman may
notice to make her think that she is pregnant?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
The Developing Baby
Here is what a developing foetus looks
like over the rest of pregnancy.
Time after
fertilisation
14 Weeks
Muscles form and the baby starts to
move. Eyelids, fingernails, toenails form.
The Developing Baby
Here is what a developing foetus looks
like over the rest of pregnancy.
Time after
fertilisation
18 Weeks
About 5 inches long. It can blink and
grasp. Hair grows all over the body.
The Developing Baby
Here is what a developing foetus looks
like over the rest of pregnancy.
Time after
fertilisation
24 Weeks
Fine hair and a waxy substance covers
the body. It starts to ‘breathe’.
The Developing Baby
Here is what a developing foetus looks
like over the rest of pregnancy.
Time after
fertilisation
30 Weeks
The baby can survive if born now. It
would be called premature.
The Developing Baby
Here is what a developing foetus looks
like over the rest of pregnancy.
Time after
fertilisation
40 Weeks
Welcome to the world. A normal baby is
born around this time.
What happens at birth?
This is a sideways
view of a pregnant
women. Can you use
it to answer the
following questions:
1. Why does a
pregnant woman need
to go to the toilet a
lot?
2. Why does her belly
button stick out?
3. Why should the
head be pointing
downwards?
What happens at birth?
What am I
thinking?
How is the baby protected?
The baby
develops
inside a sac
and is
surrounded
by water.
This stops it
from being
damaged by
movements
the mother
makes.
Question 2
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How is a baby protected from harm whilst it is
inside the mothers baby?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 2
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How is a baby protected from harm whilst it is
inside the mothers body?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 2
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How is a baby protected from harm whilst it is
inside the mothers body?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 2
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How is a baby protected from harm whilst it is
inside the mothers body?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 2
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How is a baby protected from harm whilst it is
inside the mothers body?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 2
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How is a baby protected from harm whilst it is
inside the mothers body?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
How is the baby fed?
Umbilical
cord
Placenta
The baby is
linked to the
mother by
the
umbilical
cord. It gets
its food and
oxygen via
this tube. It
links to the
placenta.
Question 3
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How does a baby get oxygen and food and get rid of
waste whilst it is in the womb?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 3
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How does a baby get oxygen and food and get rid of
waste whilst it is in the womb?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 3
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How does a baby get oxygen and food and get rid of
waste whilst it is in the womb?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 3
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How does a baby get oxygen and food and get rid of
waste whilst it is in the womb?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 3
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How does a baby get oxygen and food and get rid of
waste whilst it is in the womb?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
Question 3
Write the question and answer in your
exercise book. You have only 5 minutes
to do this!
How does a baby get oxygen and food and get rid of
waste whilst it is in the womb?
Time left to answer question
Mins.
Mins.
Mins.
Mins.
Mins.
The Developing Baby
This is a picture
of a human
placenta. It is
about the size of
a human liver.
The placenta will pass on anything that is present
in the mothers bloodstream. This includes:
•Microbes and Infections
•Alcohol
•Drugs (both medicine and illegal)
Learning Review
By the end of the lesson I would like you to be able to:
•Describe what happens to an egg cell immediately after it
has been fertilised with a sperm cell.
•Be able to organise pictures of the developing embryo
into chronological order.
•State the function of the placenta.
How well did you do?
Look at the three WILF targets above. Talk to
you partner about them. Now ask them to put
the correct number of ticks next to the lesson
objective in your book.
I’m still quite stuck
and not sure of what
we have covered in
this lesson.
I have understood
most of the ideas
we have looked at
in this lesson.
I have understood
all of the ideas we
have looked at in
this lesson.
What Order?
Can you rearrange the things below, starting with
the first, to show what happens in pregnancy.
Brain and spinal
cord develop.
Arms and legs
start to form.
Can start
blinking.
Heart starts to
beat.
Fingernails and
toenails form.
Fingerprints are
formed.
Starts to
practice
breathing.
Produces its
own digestive
juices.
What Order?
Can you rearrange the things below, starting with
the first, to show what happens in pregnancy.
Brain and spinal
cord develop.
Arms and legs
start to form.
Can start
blinking.
Heart starts to
beat.
Fingernails and
toenails form.
Fingerprints are
formed.
Starts to
practice
breathing.
Produces its
own digestive
juices.