First Children Encyclopedia

(Marvins-Underground-K-12) #1

What is another name for the uterus?


Human body


118


The first cells
After 36 hours, the cell has
divided and made an exact
copy of itself. These are the
first two cells of a baby.

Making a baby

Eggs are the biggest cells in
the human body. But they
are still very small – ten
would fit across a pinhead.

Sperm race


Millions of sperm swim towards


the egg cell. Only one sperm can


join with the egg to make a new cell.


By the time the


baby is born,


the fertilized cell


will have become


100 trillion cells.


Sperm are amazing
viewed under a microscope.
They look like tiny tadpoles. You
can see their tails wriggling as
they swim.

You need a mother and a father to


make a baby. The mother’s body does


most of the work, but the father also


has an important job – his sperm joins


with the mother’s egg and a new


life begins...

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