First
Trimester
:
The
zygote
begins
to
divide
into
several
cells
and
an
____________________
forms
.
The
____________________
attaches
to
the
____________________
of
the
uterus
(
____________________
)
.
The
____________________
____________________
forms
around
the
embryo
.
It
is
a
membrane
full
of
____________________
that
protects
the
embryo
.
The
placenta
forms
at
this
time
.
The
____________________
is
an
organ
that
permits
the
exchange
of
substances
between
the
mother's
____________________
and
the
____________________
through
the
____________________
____________________
.
Second
Trimester
:
The
embryo
becomes
a
____________________
.
It
grows
and
all
the
____________________
begin
to
form
inside
.
It
starts
to
take
on
human
form
and
begins
to
____________________
.
Third
Trimester
:
The
fetus
continues
to
____________________
and
mature
.
After
the
____________________
month
,
the
development
of
the
body
is
complete
,
although
the
____________________
and
____________________
____________________
are
not
yet
mature
.
Around
the
____________________
month
,
the
fetus
engages
with
the
head
towards
the
opening
of
the
____________________
,
in
preparation
for
____________________
.