1
SEX DETERMINATION
(
GENDER DETERMINATION PROCESS
)
Ge
n
de
r
de
t
e
rmin
a
tion typ
e
M
ost g
e
n
e
ti
ca
lly
c
ontroll
ed
g
e
n
de
r m
ec
h
a
nisms
a
n
d ca
n
be
d
ivi
ded
into s
e
v
e
r
a
l of th
e
following
ca
t
e
gori
e
s
:
He
t
e
rog
a
m
e
t
I
n hum
a
ns
a
n
d
most of th
e
m
a
mm
a
ls
,
th
e e
xist
e
n
ce
of
Y
c
hromosom
e
s
de
t
e
rmin
e
m
a
l
e c
h
a
r
ac
t
e
risti
c
s
.
N
orm
a
l m
a
l
e
h
a
s
XY
c
hromosom
e
,
whil
e
f
e
m
a
l
e
s h
a
v
e XX c
hromosom
e
s
,
pro
d
u
ce
1
:
1
s
e
x
r
a
tios in
eac
h g
e
n
e
r
a
tion
.
Ma
l
e
is
ca
ll
ed
h
e
t
e
rog
a
m
e
t
beca
us
e
it
pro
d
u
ce
s two typ
e
s of g
a
m
e
t
e
s
,
whil
e
f
e
m
a
l
e
s pro
d
u
ce
on
e
typ
e
of
g
a
m
e
t
.
T
his g
e
n
de
r
de
t
e
rmin
a
tion is usu
a
lly
ca
ll
ed
th
e XY
m
e
tho
d
.
I
n som
e
ins
ec
ts
,
a
s in th
e O
rtho
de
r
a a
n
d O
rthopt
e
r
a
or
de
rs
,
m
a
l
e
is
a
lso h
e
t
e
rog
a
m
e
t
,
b
ut pro
d
u
ce
s sp
e
rm th
a
t
ca
rri
e
s th
e
c
hromosom
e X
or
d
o
e
s not h
a
v
e
s
e
x
c
hromosom
e
s
a
t
a
ll
.
T
h
e X
c
hromosom
e
in m
a
l
e d
o
e
s not h
a
v
e a
homologous
c
oupl
e beca
us
e
th
e
r
e
is no y
c
hromosom
e
,
so th
e
num
be
r of
c
hromosom
e
s is o
dd
.
O
n
e
C
hromosom
e X de
t
e
rmin
e
s th
e
m
a
l
e
prop
e
rti
e
s
,
whil
e
two
X
c
hromosom
e
s
de
t
e
rmin
e
th
e
n
a
tur
e
of th
e
f
e
m
a
l
.
I
f
a
singl
e X
c
hromosom
e
is
a
lw
a
ys in on
e
of th
e
two typ
e
s of m
a
l
e
g
a
m
e
ts
,
th
e
n
th
e
g
e
n
de
r r
a
tio
1
:
1
will
be ac
hi
e
v
ed
to th
e
offspring
.
T
his m
e
tho
d
is
known
a
s th
e XO
m
e
tho
d
,
wh
e
r
e
th
e O
sym
b
ol shows th
e ab
s
e
n
ce
of
c
hromosom
e
s
Y
.
2
He
t
e
rog
a
m
e
ti
c
f
e
m
a
l
e
s
T
h
e
m
e
tho
d
of
de
t
e
rmining this g
e
n
de
r w
a
s foun
d
in s
e
v
e
r
a
l
l
a
rg
e
groups of
a
nim
a
ls su
c
h
a
s
b
utt
e
rfli
e
s
,
b
l
e
g
a
l
,
w
a
t
e
r
b
uffy
,
silk
ca
t
e
rpill
a
rs
,
a
n
d
som
e b
ir
d
s
a
n
d
fish
.
I
n th
e
s
e
sp
ec
i
e
s
,
on
e X
c
hromosom
e de
t
e
rmin
e
s f
e
m
a
l
e
s
,
whil
e
two
X c
hromosom
e
s
de
t
e
rmin
e
m
a
l
e
.
Fe
m
a
l
e
s in som
e
sp
ec
i
e
s
,
for
e
x
a
mpl
e d
om
e
sti
c
c
hi
c
k
e
n
,
h
a
v
e c
hromosom
e
s simil
a
r to hum
a
n
c
hromosom
e
s
,
whi
c
h
a
r
e
n
a
m
ed Z a
n
d W
r
e
pl
ac
ing
X a
n
d Y
.
H
ow
e
v
e
r
,
c
hromosom
e
s
W
in
c
hi
c
k
e
ns
d
o not h
a
v
e a
strong rol
e
in
de
t
e
rmining f
e
m
a
l
e
s
e
x
.
P
loi
d
i typ
e
S
om
e
ins
ec
ts
ca
n multiply
,
wh
e
r
e
n
e
w
c
r
ea
tur
e
s
a
r
e
form
ed
from
e
gg
ce
lls without f
e
rtiliz
a
tion
b
y sp
e
rm
a
tozo
a
.
I
n hon
e
y
bee
s
,
th
e de
t
e
rmin
a
tion of g
e
n
de
r is not influ
e
n
ced b
y
s
e
x
c
hromosom
e
,
b
ut
b
y th
e
n
a
tur
e
of th
e
ploi
d
i
.
D
iploi
d bee
s
(
2
n
)
a
r
e
f
e
m
a
l
e
s
,
whil
e
th
e
h
a
ploi
d
(
N
)
is m
a
l
e
.
De
t
e
rmin
a
tion of s
e
x on
D
rosophil
a
D
rosophil
a
fli
e
s
a
r
e
wi
de
ly us
ed
in g
e
n
e
ti
c
r
e
s
ea
r
c
h for s
e
v
e
r
a
l
r
ea
sons
:
ea
sy to m
a
int
a
in
,
short lif
e c
y
c
l
e
,
a
n
d
th
e d
iff
e
r
e
n
ce
in
a c
l
ea
r
s
ec
on
da
ry g
e
nit
a
l
.
La
rg
e
r f
e
m
a
l
e
fli
e
s
,
tip
abd
omin
a
l t
a
p
e
r
ed
with
b
l
ac
k lin
e
s
,
whil
e
m
a
l
e
sm
a
ll
e
r with
b
lunt
abd
omin
a
l tip
a
n
d
slight
b
l
ac
k
lin
e
s
.
Ma
l
e
h
a
s
a
g
e
nit
a
l
c
om
b
on th
e
front l
e
g
,
whil
e
f
e
m
a
l
e
s
a
r
e
not
.
T
his fly h
a
s
8
c
hromosom
e
s
,
c
onsisting of six
a
utosom
a
l
c
hromosom
e
s
a
n
d
two g
e
nit
a
l
c
hromosom
e
s
(
X a
n
d Y
).
Fe
m
a
l
e
s h
a
v
e
two
X
3
c
hromosom
e
s
(
homog
a
mi
c
i
c
s
),
whil
e
m
a
l
e
s h
a
v
e
on
e c
hromosom
e
-
x
a
n
d
on
e c
hromosom
e
-
y
(
h
e
t
e
rog
a
m
e
ti
c
).
T
h
e c
hromosom
e
formul
a
is
:
f
e
m
a
l
e
s
=
aa
xx
a
n
d
m
a
l
e
=
aa
xy
.
U
n
de
r norm
a
l
c
ir
c
umst
a
n
ce
s
,
f
e
m
a
l
e
s
pro
d
u
ce
h
a
ploi
d e
gg
ce
lls
(
AX
),
whil
e
m
a
l
e
pro
d
u
ce
sp
e
rm
a
tozo
a
ca
rrying
c
hromosom
e
-
x
(
a
x
)
or
c
hromosom
e
-
y
(
vv
).
I
f sp
e
rm
a
tozo
a
x
f
e
rtiliz
e
s th
e
x
e
gg
,
th
e
n th
e
f
e
m
a
l
e c
hil
d
(
AAXX
),
wh
e
r
ea
s if
sp
e
rm
a
tozo
a
y f
e
rtiliz
e
s th
e
x
e
gg
,
th
e
son is m
a
l
e
(
aa
x
).
S
om
e
tim
e
s
,
d
uring m
e
iosis
,
g
e
nit
a
l
c
hromosom
e
is not s
e
p
a
r
a
t
e
,
known
a
s
non
d
isjun
c
tion
,
pro
d
u
ce
s ovum with two
-
x
c
hromosom
e
s or without
c
hromosom
-
x
.
N
on
d
isjun
c
tion
ca
n
ca
us
e
v
a
rious
ab
norm
a
liti
e
s in offspring
,
su
c
h
a
s
:
1
.
S
up
e
r f
e
m
a
l
e
fli
e
s
(
AAXXX
):
o
cc
urs wh
e
n sp
e
rm
a
tozo
a ca
rrying
c
hromosom
e
s
-
x f
e
rtiliz
e
s th
e e
gg with two
-
x
c
hromosom
e
s
.
T
his
fli
e
s
e
xp
e
ri
e
n
ced
imp
e
rf
ec
t
,
v
e
ry w
ea
k growth
,
a
n
d
h
ad a
short lif
e
.
2
.
AAXXY
fly
:
o
cc
urs wh
e
n sp
e
rm
a
tozo
a ca
rrying
c
hromosom
e
s
-
y
f
e
rtiliz
e
th
e e
gg with two x
c
hromosom
e
s
.
T
h
e
s
e
fli
e
s
a
r
e
f
e
m
a
l
e
,
f
e
rtil
e
,
a
n
d
no
d
iff
e
r
e
nt from or
d
in
a
ry f
e
m
a
l
e
fli
e
s
,
in
d
i
ca
ting th
a
t
th
e Y c
hromosom
e d
o
e
s not
a
ff
ec
t th
e
s
e
x of
D
rosophil
a
.
3
.
AAXO
fli
e
s
:
o
cc
urs wh
e
n sp
e
rm
a
tozo
a ca
rrying
c
hromosom
e
s
-
x
f
e
rtiliz
e
s th
e e
gg without
c
hromosom
e
-
x
.
T
h
e
s
e
fli
e
s
a
r
e
m
a
l
e a
n
d
st
e
ril
e
,
whil
e XO
hum
a
ns
a
r
e
st
e
ril
e
wom
e
n
a
n
d XO
mi
ce a
r
e
f
e
m
a
l
e
f
e
m
a
l
e
s
.
4
.
D
rosophil
a Y
o
:
U
nknown
beca
us
e
if sp
e
rm
a
tozo
a
with
4
c
hromosom
e
s
-
y f
e
rtiliz
e
s th
e e
gg without
c
hromosom
e
-
x
,
will
be
f
a
t
a
l
.
I
n
add
ition
,
th
e
r
e a
r
e
s
e
v
e
r
a
l oth
e
r
ab
norm
a
liti
e
s on
D
rosophil
a
,
su
c
h
a
s
:
-
G
in
a
n
d
romorf fli
e
s
:
h
a
v
e a b
o
d
y th
a
t is h
a
lf
a
f
e
m
a
l
e a
n
d
h
a
lf m
a
l
e
with
a c
l
ea
r limit
.
G
in
a
n
d
romorphism is
a
lso foun
d
in silk
a
n
d
bee
worms
.
I
n v
e
rt
eb
r
a
t
e
s
,
gin
a
n
d
romorphism is
d
iffi
c
ult to
de
t
ec
t
beca
us
e
of th
e
v
a
ri
ab
ility
a
n
d
int
e
r
ac
tion of s
e
xu
a
l hormon
e e
ff
ec
ts
.
-
I
nt
e
rs
e
x fli
e
s
(
AAAXX
):
I
t is
a
mixtur
e
of f
e
m
a
l
e a
n
d
m
a
l
e
fli
e
s
,
triploi
d
for its
a
utosom
,
h
a
s two
X c
hromosom
e
s
,
a
n
d
st
e
ril
e
.
N
ow
known
a
s triploi
d
int
e
rs
e
x fli
e
s
a
ft
e
r
B
ri
d
g
e
s
c
r
ea
t
e
s v
a
rious kin
d
s of
d
rosophil
a
t
e
tr
a
ploi
d
s su
c
h
a
s t
e
tr
a
ploi
d
f
e
m
a
l
e
s
(
AAAAXXXX
),
int
e
rs
e
x t
e
tr
a
ploi
d
(
AAAAXXX
),
a
n
d
sup
e
r m
a
l
e Te
tr
a
ploi
d
(
AAAAX
).
-
S
up
e
r m
a
l
e
fli
e
s
(
aaa
xy
):
m
a
l
e
triploi
d
for
a
utosom
.
L
ik
e
sup
e
r
f
e
m
a
l
e
fli
e
s
,
th
e
growth is not p
e
rf
ec
t
,
st
e
ril
e
,
v
e
ry w
ea
k
,
a
n
d
lif
e
is
not long
.
-
mol
e
s with
c
hromosom
e
-
x
a
tt
ac
h
ed
to on
e e
n
d
("
A
tt
ac
h
ed
-
x
C
hromosom
e
s
"):
Ha
v
e
ph
e
notyp
e
s su
c
h
a
s norm
a
l f
e
m
a
l
e
fli
e
s
,
b
ut
mi
c
ros
c
opi
c
shows th
a
t th
e ce
ll
c
or
e c
ont
a
ins
a
p
a
ir of
c
hromosom
e
-
x
a
tt
ac
h
ed
to on
e T
h
e
tip
,
c
oupl
ed
with th
e Y c
hromosom
e
.
T
his fly
h
a
s
a AAXXY
formul
a
.
T
h
e
ory of
ba
l
a
n
ce ab
out s
e
x
:
B
ri
d
g
e
s
c
on
c
lu
ded
th
a
t
D
rosophil
a
'
s s
e
x w
a
s not only
de
p
e
n
de
nt on
th
e e
xist
e
n
ce
of
c
hromosom
e
-
x
a
n
d c
hromosom
e
s
,
b
ut
de
t
e
rmin
ed
b
y th
e
g
e
n
de
r in
de
x
,
n
a
m
e
ly th
e
r
a
tio
be
tw
ee
n th
e
num
be
r of
c
hromosom
e
s
-
x to th
e
num
be
r of s
e
ts of
a
utosom
e
s
(
x
/
a
).
T
his
th
e
ory is known
a
s th
e ba
l
a
n
ce
th
e
ory of s
e
x from
B
ri
d
g
e
s
.
5
C
hromosom
e
formul
a
X
/
a
s
e
x in
de
x
Se
x
Aa
xxx
Aa
xx
Aaa
xx
Aa
xy
Aaa
xy
3
/
2
=
1
.
50
2
/
2
=
1
.
00
2
/
3
=
0
.
67
½ =
0
.
50
1
/
3
=
0
.
33
S
up
e
rfin
e
Fe
m
a
l
e
I
nt
e
rs
e
ks
Ma
l
e
Ma
l
e
sup
e
r
I
t
ca
n
be
s
ee
n th
a
t f
e
m
a
l
e
fli
e
s h
a
v
e a
g
e
nit
a
l in
de
x
1
,
m
a
l
e
fli
e
s
0
.
5
,
be
tw
ee
n th
e
s
e
two v
a
lu
e
s
a
r
e
int
e
rs
e
x fli
e
s
,
l
e
ss th
a
n
0
.
5
a
r
e
sup
e
r
m
a
l
e
fli
e
s
,
whil
e
mor
e
th
a
n
1
sup
e
r f
e
m
a
l
.
1
.
Ge
n
e
s th
a
t
de
t
e
rmin
e
th
e
m
a
l
e
,
a
pp
a
r
e
ntly
ca
rri
ed b
y
a
utosom
e
s
.
W
hil
e
g
e
n
e
s th
a
t
de
t
e
rmin
e
f
e
m
a
l
e
s
a
r
e ca
rri
ed b
y
c
hromosom
e
-
x
.
2
.
C
hromosom
e
-
y s
e
t mor
e
f
e
rtiliz
a
tion in m
a
l
e
fli
e
s
.
T
h
e
r
e
for
e Aa
xy
fli
e
s
a
r
e
m
a
l
e
who
ca
n form sp
e
rm
a
tozo
a
.
C
hromosom
e
-
y h
a
s no
influ
e
n
ce
on
AAX
xy fli
e
s
a
n
d ba
s
ed
on th
e
g
e
nit
a
l in
de
x of
1
.
00
,
th
e
n this f
e
m
a
l
e
fly
.
3
.
Ge
n
de
r in
de
x
(
x
/
a
)>
1
.
00
or
<
0
.
50
pro
d
u
ce ab
norm
a
liti
e
s in
D
rosophil
a
(
sup
e
r f
e
m
a
l
a
n
d
sup
e
r m
a
l
e
)
4
.
Ge
n
de
r in
de
x
<
1
.
00
b
ut
>
0
.
50
pro
d
u
ce
s fli
e
s
be
tw
ee
n f
e
m
a
l
e
s
a
n
d
m
a
l
e
(
INTERSECH
).
He
t
e
ropi
c
nosis
c
hromosom
e
s
e
x
a
n
d
s
e
x v
e
si
c
l
e
s
D
uring m
e
iosis
,
XY c
hromosom
e
s
a
r
e
pl
a
nt
ed
in s
e
x v
e
si
c
l
e
s in
most m
a
mm
a
ls
.
T
his v
e
si
c
l
e a
pp
ea
rs
d
uring th
e
zygon
e
m
a
ph
a
s
e a
n
d
Pa
kin
e
m
a
,
wh
e
n
XY c
hromosom
e
is not h
e
t
e
ropi
c
noti
c
.
A
t th
e e
n
d
of
th
e
ph
a
s
e
of prof
a
s
e
,
th
e XY c
hromosom
e
whi
c
h
b
iv
a
l
e
n r
e
turn
ed
to
6
h
e
t
e
ropi
c
noti
c
.
Se
x v
e
si
c
l
e
s on mous
e
s
e
x
c
hromosom
e
s
a
ff
ec
t th
e
form
a
tion of nu
c
l
e
olus
,
beca
us
e
th
e
v
e
si
c
l
e c
ont
a
ins nu
c
l
e
ol
a
r
org
a
niz
e
rs
.
T
h
e
s
e
v
e
si
c
l
e
s h
a
v
e
two zon
e
s
: (
1
)
O
v
a
l
c
hrom
a
tin zon
e
a
tt
ac
h
ed
to th
e
nu
c
l
ea
r m
e
m
b
r
a
n
e a
n
d
(
2
)
gr
a
y nu
c
l
e
ol
a
r zon
e
.
C
hrom
a
tin in this zon
e
is thin
,
c
onsists of mi
c
rofi
b
ril
DNA c
oils
a
n
d
som
e
fil
a
m
e
nts
.
T
h
e
nu
c
l
e
ol
a
r zon
e c
ont
a
ins
a
n
e
g
a
tiv
e RNA
to
Fe
ulg
e
n
c
oloring
,
with th
e ce
nt
e
r of th
e c
row
ded
zon
e a
roun
d
th
e
ed
g
e
,
whil
e
th
e
r
e
st is
a
spong
e
stru
c
tur
e
of th
e
gr
a
nul
e
of
a
roun
d
15
nm
.
Se
x v
e
si
c
l
e
s in hum
a
ns
d
o not
c
ont
a
in
RNA a
n
d d
o not h
a
v
e a
nu
c
l
e
ol
a
r zon
e
.
Ne
o
-
xy syst
e
m in s
e
x
de
t
e
rmin
a
tion
I
n
add
ition to th
e
g
e
n
de
r
de
t
e
rmin
a
tion syst
e
m using
XY
c
hromosom
e
,
som
e
sp
ec
i
e
s us
e
th
e Ne
o
-
XY
syst
e
m
.
T
his syst
e
m
c
om
e
s from th
e X c
hromosom
e
pr
e
v
e
ntion whi
c
h th
e
n joins th
e
A
utosom to form th
e Ne
o
-
X c
hromosom
e
.
D
uring m
e
iosis
,
n
e
o
-
y
c
hromosom
e
s
a
r
e
form
ed a
n
d
p
a
ir
ed
with n
e
o
-
x
c
hromosom
e
s
,
pro
d
u
c
ing m
a
l
e
g
e
nit
a
l
ce
lls
.
T
h
e
r
e
is
e
vi
de
n
ce
th
a
t th
e
n
e
o
-
y
c
hromosom
e
gr
ad
u
a
lly turns into
a
h
e
t
e
ro
c
hrom
a
tin
,
whi
c
h is s
ee
n
through r
ad
io
a
utogr
a
phy with
H
-
T
hymi
d
in in th
e X a
n
d Ne
o
-
Y
c
hromosom
e
s
d
uring th
e
synth
e
sis p
e
rio
d
.
Se
x
d
iff
e
r
e
nti
a
tion
A
lthough s
e
xu
a
l
de
t
e
rmin
a
tion o
cc
urs in
e
m
b
ryoni
c
f
e
rtiliz
a
tion
,
th
e e
x
ac
t m
ec
h
a
nism of s
e
x
c
h
a
r
ac
t
e
risti
c
s is mor
e c
ompl
e
x
.
E
pig
e
n
e
ti
c
f
ac
tors
,
su
c
h
a
s hormon
e
s
,
ca
n
a
ff
ec
t g
e
n
e
ti
c de
t
e
rmin
a
tion
d
uring
de
v
e
lopm
e
nts
,
whi
c
h l
ead
to g
e
nit
a
l ph
e
notypi
ca
l
c
h
a
ng
e
s
.
7
B
is
e
xu
a
l
c
on
d
itions
a
r
e a
lso foun
d
on v
e
rt
eb
r
a
t
e
s
,
su
c
h
a
s m
a
l
e
a
mphi
b
i
a
ns who h
a
v
e
ru
d
im
e
nt
a
ry ov
a
ri
e
s
(
b
i
dde
r
'
s org
a
n
)
a
n
d
v
e
stigi
a
l ovi
d
uk
.
I
n hum
a
n
e
m
b
ryos to sixth w
ee
k
,
gon
ad a
n
d
primor
d
i
a
l urog
e
nit
a
l
c
h
a
nn
e
ls
a
r
e
simil
a
r
be
tw
ee
n m
e
n
a
n
d
wom
e
n
.
T
h
e
gon
ad
turns into
a
t
e
sti
c
ul
a
r in th
e
7
th w
ee
k
,
whil
e
th
e
f
e
m
a
l
e
gon
ad
is
d
iff
e
r
e
nti
a
t
ed be
tw
ee
n th
e
8
th
a
n
d
9
th w
ee
ks
.
I
mport
a
nt
e
pig
e
n
e
ti
c
f
ac
tors in
d
iff
e
r
e
nti
a
tion
a
r
e a
n
d
rog
e
n pro
d
u
c
tion
b
y
som
a
ti
c ce
lls in m
a
l
e
gon
ad
s
,
whil
e
th
e
pro
d
u
c
tion of
a
n
d
rog
e
ns in
f
e
m
a
l
e
s is v
e
ry low
.
A
n
d
rog
e
n pro
d
u
c
tion in moth
e
rs m
a
y
a
ff
ec
t
g
e
nit
a
l
d
iff
e
r
e
nti
a
tion to
bec
om
e
m
a
l
e
s
(
f
e
minin
e
ps
e
u
d
oh
e
rm
a
phro
d
itism
).
G
on
ad d
iff
e
r
e
nti
a
tion in m
e
n is
e
stim
a
t
ed
to
de
p
e
n
d
on th
e
pro
d
u
c
tion of lo
ca
l hormon
e
s r
e
l
a
t
ed
to
c
hromosom
e
s
Y
,
whi
c
h
acce
l
e
r
a
t
e
th
e de
v
e
lopm
e
nt of th
e
t
e
stis
,
whil
e
th
e ab
s
e
n
ce
of
hormon
e
s
ca
us
e
s
a
slow
d
own in th
e
ov
a
ry of wom
e
n
.
C
hrom
a
tin s
e
x
I
n
1940
,
Ba
rr from th
e U
niv
e
rsity of
We
st
e
rn
O
nt
a
rio foun
d
th
e
c
hrom
a
tin
b
o
d
y in f
e
m
a
l
e ca
t n
e
rv
e ce
lls
,
b
ut not in m
a
l
e ca
ts
.
T
his
r
e
s
ea
r
c
h
c
ontinu
e
s in hum
a
ns
,
fin
d
ing
c
hrom
a
tin
b
o
d
i
e
s in th
e
or
a
l
mu
c
os
a
l
e
pith
e
li
a
l
ce
lls
a
n
d
l
e
uko
c
yt
e ce
lls in wom
e
n
,
whi
c
h
a
r
e
roun
d
a
n
d
lik
e d
rumsti
c
ks
.
Beca
us
e
th
e
r
e
is
a
r
e
l
a
tionship
be
tw
ee
n th
e
c
hrom
a
tin
a
n
d
s
e
x
,
this
b
o
d
y is
ca
ll
ed a
s
e
x
c
hrom
a
tin or
b
o
d
y of th
e
Ba
rr
.
W
om
e
n h
a
v
e
positiv
e c
hrom
a
tin s
e
x
,
whil
e
n
e
g
a
tiv
e
m
e
n
.
T
h
e L
yon hypoth
e
sis sugg
e
sts th
a
t
c
hrom
a
tin s
e
x
c
onsists of
on
e
of th
e
two
X c
hromosom
e
s in th
e c
or
e
of th
e b
o
d
y of th
e
f
e
m
a
l
e
8
b
o
d
y
.
I
f
a ce
ll
d
o
e
s not
e
xp
e
ri
e
n
ce
mitosis
,
th
e
su
b
st
a
n
ce
of on
e
c
hromosom
e
-
x
bec
om
e
s l
e
ss visi
b
l
e
,
whil
e
oth
e
r
X c
hromosom
e
s
r
e
m
a
in
c
omp
ac
t
a
n
d
known
a
s
c
hrom
a
tin s
e
x
.
Ge
n
e
s in th
e c
omp
ac
t
X
c
hromosom
e a
r
e
not
ac
tiv
e
,
whil
e
th
e
g
e
n
e
in th
e
l
e
ss
c
omp
ac
t
-
X
c
hromosom
e
r
e
m
a
ins
ac
tiv
e
ly
a
ff
ec
ting th
e
ph
e
notyp
e
.
I
n norm
a
l
p
e
opl
e
,
th
e
num
be
r of
c
hrom
a
tin s
e
x in th
e
s
a
m
e ce
ll
a
s th
e
num
be
r of
c
hromosom
e
s is r
ed
u
ced b
y on
e
.
T
hus
,
wom
e
n h
a
v
e
two
c
hromosom
e
s
a
n
d
on
e c
hrom
a
tin s
e
x
,
whil
e
m
e
n only h
a
v
e
on
e c
hromosom
e
-
x
without
c
hrom
a
tin s
e
x
.
I
n
d
ivi
d
u
a
l
XO
is
a
wom
a
n without
c
hrom
a
tin s
e
x
,
whil
e XXY
is
a
m
a
n with on
e c
hrom
a
tin s
e
x
,
a
n
d
xxxx is
a
wom
a
n with
thr
ee c
hrom
a
tin s
e
x
.
D
is
ea
s
e
s r
e
l
a
ting to
c
hromosom
e
-
x
,
su
c
h
a
s
Le
s
c
h
-
N
yh
a
n
S
yn
d
rom
e
,
is
a
n
e
nzym
e de
fi
c
i
e
n
c
y in purin
e
m
e
t
ab
olism
,
whi
c
h is
ca
us
ed b
y
a
r
ece
ssiv
e
-
X c
hromosom
e
mut
a
tion
,
r
e
sulting in
m
e
nt
a
l
de
l
a
y
a
n
d
in
c
r
ea
s
ed
uri
c ac
i
d
l
e
v
e
ls
.
C
hrom
a
tin s
e
x with s
e
x r
a
tio
a
n
d dea
th
C
hrom
a
tin s
e
x t
e
sts
a
r
e
us
ed
to
de
t
e
rmin
e
th
e
r
a
tio of m
e
n tow
a
r
d
s
wom
e
n sin
ce
th
e c
on
ce
ption
.
Re
s
ea
r
c
h th
a
t utiliz
e
s this t
e
st shows th
a
t
mor
e
m
e
n
'
s
c
on
ce
ptions o
cc
ur
c
omp
a
r
ed
to wom
e
n
,
e
v
e
n though m
e
n
e
xp
e
ri
e
n
ce
spont
a
n
e
ous
ab
ortion mor
e
oft
e
n
.
F
or
e
x
a
mpl
e
,
th
e
r
e a
r
e
106
m
e
n
b
orn for
e
v
e
ry
100
wom
e
n
,
b
ut
a
t th
e a
g
e
of
20
th
e
r
a
tio
c
h
a
ng
ed
to
100
m
e
n for
100
wom
e
n
,
a
n
d a
t th
e a
g
e
of
85
y
ea
rs to
62
m
e
n for
100
wom
e
n
.
A
high
e
r mort
a
lity r
a
t
e
in m
e
n th
a
n wom
e
n m
a
y
be ca
us
ed b
y th
e
surviv
a
l
be
n
e
fits provi
ded b
y two
X c
hromosom
e
s in
wom
e
n
,
c
omp
a
r
ed
to on
e
-
X c
hromosom
e
in m
e
n
.
Ge
n
de
r s
e
ri
e
s is
a
g
e
n
e
lo
ca
t
ed
on s
e
x
c
hromosom
e
s
b
ut is not
involv
ed
in
de
t
e
rmining s
e
x
.
A
t
D
rosophil
a
,
wh
e
n th
e
homozygous
9
f
e
m
a
l
e
s with r
ed e
y
e
s
(
d
omin
a
nt
)
a
r
e c
ross
ed
with
a
whit
e
m
a
l
e e
y
e
(
r
ece
ssiv
e
),
a
ll f
1
de
s
ce
n
da
nts h
a
v
e
r
ed e
y
e
s
.
H
ow
e
v
e
r
,
wh
e
n th
e
whit
e
f
e
m
a
l
e e
y
e
s of th
e F
1
g
e
n
e
r
a
tion
c
ross
ed
with r
ed e
y
e
s
,
th
e
offspring is
a
m
a
l
e
whit
e e
y
e
.
I
t shows th
a
t r
ed e
y
e
g
e
n
e
s li
e
in th
e c
hromosom
e X
,
not
Y
.
on th
e XY
s
e
x
de
t
e
rmin
a
tion syst
e
m
,
g
e
n
e
s on
X a
n
d Y a
r
e
not
homologous
a
n
d
h
a
v
e
not
e
xp
e
ri
e
n
ced c
rossing ov
e
r
.
T
h
e
r
e a
r
e
thr
ee
typ
e
s of s
e
x
:
1
.
Ge
n lo
ca
t
ed
on
c
hromosom
e X
,
su
c
h
a
s g
e
n
e
s for r
ed
-
gr
ee
n
b
lin
d
n
e
ss
(
Da
ltonism
)
a
n
d
h
e
mophili
a
.
Da
ltonism is mor
e c
ommon in
m
e
n
(
8
%
)
th
a
n wom
e
n
(
0
.
5
%
),
a
n
d
h
e
mophili
a
is l
e
ss
c
ommon in
wom
e
n
.
2
.
T
h
e
g
e
n
e
s lo
ca
t
ed
on
Y c
hromosom
e
s
,
su
c
h
a
s
Ic
hthyosis
H
ystrix
G
r
a
vis
,
inh
e
rit
ed d
ir
ec
tly from th
e
f
a
th
e
r to his son
.
3
.
T
h
e
g
e
n
e
s lo
ca
t
ed
in th
e
homolog s
e
gm
e
nt on th
e X a
n
d Y
c
hromosom
e
s
(
e
qu
a
ls in
c
ompl
e
t
e
),
inh
e
rit
ed a
s
a
utosom
a
l g
e
n
e
s
a
n
d
only p
a
rti
a
l r
e
l
a
t
ed
to s
e
x
.
E
x
a
mpl
e
s in
c
lu
de
tot
a
l
c
olor
b
lin
d
n
e
ss
a
n
d
skin
d
isor
de
rs su
c
h
a
s x
e
ro
de
rm
a
pigm
e
ntosum
.
T
h
e
hum
a
n
c
ytog
e
n
e
ti
c
is
a b
r
a
n
c
h of s
c
i
e
n
ce
th
a
t stu
d
i
e
s
c
hromosom
e be
h
a
vior
d
uring mitosis
a
n
d
m
e
iosis
,
a
s w
e
ll
a
s
c
h
a
ng
e
s
in th
e
stru
c
tur
e a
n
d
num
be
r of
c
hromosom
e
s
.
Tec
hniqu
e
s su
c
h
a
s
c
ultur
e
of
a
mnioti
c
flui
d a
r
e
us
ed
to
d
i
a
gnos
e c
hromosom
e
ab
norm
a
liti
e
s in n
e
w
b
orns
.
N
orm
a
l hum
a
n k
a
ryotyp
e
s for wom
e
n
a
n
d
m
e
n
eac
h
a
r
e
46
,
xx
a
n
d
46
,
xy
.
C
hromosom
e
s
a
r
e a
lso group
ed ba
s
ed
on th
e
position of
10
ce
ntrom
e
rs to m
e
t
a
s
e
ntri
c
,
su
b
m
e
t
a
s
e
ntri
c
,
a
n
d ac
ro
ce
ntri
c
,
a
s shown
in th
e Ka
ryotyp
e
t
ab
l
e ba
s
ed
on
De
nv
e
r
a
n
d L
on
d
on r
e
ports
.
De
nv
e
r
Re
port
L
on
d
on
Re
port
De
s
c
ription
G
roup
1
-
3
G
roup
1
-
3
(
a
)
La
rg
e c
hromosom
e
s with
ce
ntrom
e
rs in th
e
mi
dd
l
e
of th
e
mi
dd
l
e
:
1
,
2
a
n
d
3
ca
n usu
a
lly
be
i
de
ntifi
ed
morfoogi
G
roup
4
-
5
G
roup
4
-
5
(
B
)
B
ig su
b
m
e
t
a
s
e
ntri
c c
hromosom
e
G
roup
6
-
12
G
roup
X
.
6
-
12
(
c
)
M
o
de
r
a
t
e
siz
e
su
b
m
e
t
a
s
e
ntri
c
c
hromoso
G
roup
13
-
15
G
roup
13
-
14
(
D
)
G
r
ea
t
ac
ro
ce
ntri
c c
hromosom
e
G
roup
16
-
18
G
roup
16
-
18
(
e
)
N
o
.
16
is m
e
t
a
s
e
ntri
c
;
no
.
17
-
18
is
a
sm
a
ll su
b
m
e
t
a
s
e
ntri
c
c
hromosom
e
G
roup
19
-
20
G
roup
19
-
20
(
F
)
S
m
a
ll m
e
t
a
s
e
ntri
c c
hromosom
e
G
roup
21
-
22
G
roup
21
-
22
+
Y
(
g
)
S
hort
ac
ro
ce
ntri
c c
hromosom
e
s
(
Y
c
hromosom
e
s
a
r
e
in
c
lu
ded
in this
group
,
b
ut
d
o not h
a
v
e
s
a
t
e
llit
e
s
,
this is
de
t
e
rmin
ed ba
s
ed
on siz
e
a
n
d ca
n
a
lso
be
r
ec
ogniz
ed
morphologi
ca
lly
)
Se
x
c
hromosom
e
Y
X
11
C
h
a
ng
e
s in th
e
num
be
r of
c
hromosom
e
s
ca
n
ca
us
e ab
norm
a
liti
e
s
,
su
c
h
a
s
T
risomy
21
(
M
ongolism
).
I
n
d
ivi
d
u
a
ls with this
d
isor
de
r
e
xp
e
ri
e
n
ce
m
e
nt
a
l r
e
t
a
r
da
tion
,
short
b
o
d
y
,
e
y
e
fol
d
s simil
a
r to th
e
M
ongol r
ace
,
short
a
n
d
f
a
t fing
e
rs
,
swoll
e
n tongu
e
s
,
a
n
d
imp
e
rf
ec
t
n
e
rvous syst
e
ms
.
I
n twins
,
only on
e bab
y might
e
xp
e
ri
e
n
ce
this
d
isor
de
r
.
M
ongoloi
d
h
a
s
e
xtr
a c
hromosom
e
s in th
e
21
st p
a
ir
,
known
a
s trisomy
,
d
u
e
to non
d
isjun
c
tion
d
uring m
e
iosis
.
I
n som
e ca
s
e
s
,
e
xtr
a c
hromosom
e
s
ca
n
be a
tt
ac
h
ed
to
a
utosom
e
s
,
usu
a
lly p
a
irs
22
.
M
ongoloi
d c
h
a
r
ac
t
e
risti
c
s in
c
lu
de e
pi
ca
nti
c
fol
d
s
,
wi
de e
y
e d
ist
a
n
ce
,
pug nos
e
,
imp
e
rf
ec
t
ea
rs
,
a
n
d
th
e
mouth op
e
n with tongu
e
sti
c
king
out
.
T
h
e
pr
e
v
a
l
e
n
ce
is
0
.
1
%
a
t
b
irth
,
a
n
d M
ongolism
d
u
e
to
tr
a
nslo
ca
tion o
cc
urs in
3
-
4
%
of
ca
s
e
s
.
Ka
ryotyp
e
s
a
r
e
us
ed
to
d
i
a
gnos
e
this
c
on
d
ition
,
a
n
d
th
e
risk of in
c
r
ea
sing in moth
e
rs ov
e
r
35
y
ea
rs ol
d
.
T
his
c
on
d
ition
ca
n
a
lso o
cc
ur in your
b
roth
e
r or n
e
xt
g
e
n
e
r
a
tion
.
21
-
M
onosomy
,
whi
c
h is losing on
e
of th
e c
hromosom
e
s in th
e
21
st
p
a
ir
,
is l
e
t
a
l
.
C
hil
d
r
e
n with this
c
on
d
ition m
a
y h
a
v
e
th
e
c
h
a
r
ac
t
e
risti
c
s th
a
t
a
r
e c
ontr
a
ry to
M
ongolism
,
su
c
h
a
s th
e
nos
e
st
a
n
d
s out
,
short
e
r
e
y
e d
ist
a
n
ce
,
a
n
d b
ig
ea
rs with mus
c
l
e
sp
a
sms
.
T
risomy
18
ca
us
e
s sm
a
ll
a
n
d
w
ea
k
b
orn
c
hil
d
r
e
n
,
with fl
a
t h
ead
,
th
e
ea
rs
a
r
e
l
e
ss
de
v
e
lop
ed
,
short h
a
n
d
s
,
a
n
d
m
e
nt
a
l r
e
t
a
r
da
tion
,
oft
e
n
d
i
e be
for
e
on
e
y
ea
r
.
M
onosomy
18
is th
e
opposit
e
syn
d
rom
e
of th
e
loss of th
e
12
c
hromosom
e
p
a
ir
,
with
ea
r
be
rr
e
li
e
f
,
long fing
e
r
,
a
n
d c
ompli
ca
t
ed
vision
.
T
risomy
13
,
or p
a
t
a
u syn
d
rom
e
,
ca
us
e
s th
e b
o
d
y is not p
e
rf
ec
t
a
n
d
m
e
nt
a
l r
e
t
a
r
da
tion with
c
h
a
r
ac
t
e
risti
c
s su
c
h
a
s sm
a
ll h
ead
s
,
c
l
e
ft
lips
,
a
n
d b
r
a
in
a
n
d
imp
eccab
l
e
int
e
rn
a
l org
a
ns
,
oft
e
n
ca
us
e dea
th
imm
ed
i
a
t
e
ly
a
ft
e
r
b
irth
.
Ab
norm
a
liti
e
s
d
u
e
to
c
h
a
ng
e
s in
c
hromosom
e
stru
c
tur
e
s in
c
lu
de
:
-
De
l
e
si
(
de
fi
c
i
e
n
c
y
):
loss of
b
rok
e
n
c
hromosom
e
s
a
n
d d
o
e
s not
h
a
v
e a ce
ntrom
e
r
e
,
a
s in
CRI DU C
h
a
t
.
S
igns in
c
lu
de
sm
a
ll h
ead
s
,
wi
de
f
ace
s
,
s
add
l
e
nos
e
s
,
f
a
r
a
p
a
rt
e
y
e
s
,
a
n
d
m
e
nt
a
l
d
isor
de
rs
.
Pa
ti
e
nts
d
o not inh
e
rit this
de
fi
c
i
e
n
c
y to his offspring
.
-
D
upli
ca
tion
:
T
h
e add
ition of r
e
p
e
titiv
e
g
e
n
e
s in th
e c
hromosom
e
s
ec
tion
,
is oft
e
n
a
sso
c
i
a
t
ed
with
c
hromosom
e
tr
a
nslo
ca
tion
a
n
d
de
fi
c
i
e
n
c
y
.
F
or
e
x
a
mpl
e
,
d
upli
ca
tion on
A
utosom
N
o
.
6
oft
e
n r
e
sults
in inf
a
nt mort
a
lity
.
-
I
nv
e
rsion
:
T
h
e c
hromosom
e
p
a
rt w
a
s r
e
v
e
rs
ed a
ft
e
r
b
rok
e
n in two
pl
ace
s
a
n
d
sti
c
king
bac
k in r
e
v
e
rs
e
st
a
t
e
.
-
C
hromosom
e
s
R
ing
:
B
rok
e
n
c
hromosom
e
s in two pl
ace
s
p
e
ris
e
ntri
c
,
th
e
n form
a
ring
.
R
ing
c
hromosom
e
s
ca
n
a
ff
ec
t m
e
nt
a
lly
a
n
d
physi
ca
lly
a
n
d a
r
e
foun
d
in
A
utosom
N
o
.
5
,
13
,
18
,
a
n
d
21
or
22
.
He
rm
a
fro
d
itism involv
e
s in
d
ivi
d
u
a
ls with t
e
sti
c
ul
a
r
a
n
d
ov
a
ri
a
n
tissu
e
.
S
tu
d
i
e
s show
c
hromosom
e a
n
d c
hrom
a
tin
e
s
e
x v
a
ri
a
tions in
108
tru
e ca
s
e
s of h
e
rm
a
phro
d
itism
.
P
s
e
u
d
oh
e
rm
a
fro
d
itism is
a
c
on
d
ition in whi
c
h in
d
ivi
d
u
a
ls h
a
v
e
on
e
typ
e
of gon
ad
(
t
e
sti
c
l
e
s or
13
ov
a
ri
e
s
)
b
ut not p
e
rf
ec
t
.
Se
x
c
hromosom
e ab
norm
a
liti
e
s
a
r
e ca
us
ed b
y th
e e
x
ce
ss num
be
r of
s
e
x
c
hromosom
e
s
,
with
d
iff
e
r
e
nt fr
e
qu
e
n
c
i
e
s r
e
gist
e
r
ed ba
s
ed
on
da
t
a
from
1980
in th
e U
nit
ed S
t
a
t
e
s
.
14
K
in
d
s of
ab
norm
a
liti
e
s
C
hromoso
m
e
c
om
b
in
a
ti
on
A
lot of
c
hrom
a
tin
s
e
x
T
h
e
num
be
r
of som
a
ti
c
c
hromosom
e
s
Se
x
Fe
rtility
F
r
e
qu
e
n
c
y
e
stim
a
t
ed
e
v
e
ry
1
,
000
T
h
e e
stim
a
t
ed
a
mount in
A
m
e
ri
ca
T
urn
e
r
K
lin
e
f
e
lt
e
r
X
xyy
K
linf
e
lt
e
r
KLINFELTE
R XXXYY
T
riplo
-
x
Te
tr
a
-
x
T
riplo
-
x
,
y
Te
tr
a
-
x
,
y
Pe
nt
a
-
x
Aa
x
Aa
xxy
Aa
xxyy
Aa
xxxyy
Aa
xxx
Aa
xxxx
Aa
xxxy
Aa
xxxxy
Aa
xxxxx
-
1
1
2
2
3
2
3
4
45
47
48
49
47
48
48
49
49
W
om
e
n
Me
n
Me
n
Me
n
W
om
e
n
W
om
e
n
Me
n
Me
n
W
om
e
n
(
─
) +
─
?
?
+
?
─
─
─
0
,
2
-
0
,
4
2
,
0
Pec
uli
a
r
Pec
uli
a
r
0
,
75
Pec
uli
a
r
Pec
uli
a
r
Pec
uli
a
r
Pec
uli
a
r
45
.
300
-
90
.
600
453
.
000
Pec
uli
a
r
Pec
uli
a
r
169
.
880
Pec
uli
a
r
Pec
uli
a
r
Pec
uli
a
r
Pec
uli
a
r
15
X
y y
Aa
xyy
-
47
Me
n
0
,
7
-
2
,
0
186
.
500
-
453
.
000
De
s
c
ription
:
+
for f
e
rtility
=
f
e
rtil
e
─
no f
e
rtil
e
g
e
n
e
r
a
lly inf
e
rtil
e beca
us
e
of th
e
num
be
r of sp
e
rm littl
e
16
T
urn
e
r
S
yn
d
rom
e
S
ymptoms th
a
t
a
ris
e
in
c
lu
de
short h
e
ight
,
a
roun
d
120
c
m in
ad
ulthoo
d
,
a
short n
ec
k with th
e ba
s
e
looks lik
e
winging
,
wi
de c
h
e
st
,
a
n
d
l
ac
k of
de
v
e
lopm
e
nt of s
ec
on
da
ry s
e
xu
a
l s
e
x
.
U
n
de
r
e
xtr
e
m
e c
on
d
itions
,
n
ec
k
skin
ca
n
be
v
e
ry s
a
gging
.
T
urn
e
r syn
d
rom
e ca
n
be ca
us
ed b
y
non
d
iskojun
c
tion wh
e
n th
e
form
a
tion of
a
n
e
gg
b
y th
e
moth
e
r or loss
of s
e
x
c
hromosom
e
s
d
uring mitosis
a
ft
e
r zygot xx or xy is form
ed
.
I
n
add
ition
,
th
e
r
e a
r
e a
lso thos
e
m
e
ntioning th
e ca
us
e a
s
a
mos
a
i
c
with
th
e X
/
XX c
hromosom
e
.
K
linf
e
lt
e
r
S
yn
d
rom
e
T
h
e
s
e
syn
d
rom
e
suff
e
r
e
rs show signs of f
e
miniz
a
tion su
c
h
a
s
b
r
ea
st
growth
,
l
ac
k of h
a
ir growth
,
a
n
d
v
e
ry long
a
rms
a
n
d
l
e
gs so th
a
t th
e
b
o
d
y looks high
.
T
h
e
ir voi
ce
s t
e
n
d
to
be
high lik
e
th
e
ir wom
e
n
a
n
d
th
e
ir sm
a
ll t
e
st
e
s
.
Pa
ti
e
nts oft
e
n
e
xp
e
ri
e
n
ce
m
e
nt
a
l
d
isor
de
rs
.
K
linf
e
lt
e
r
syn
d
rom
e
is g
e
n
e
r
a
lly
ca
us
ed b
y non
d
isjun
c
tion xx
d
uring oog
e
n
e
sis
.
T
riplo
-
X S
yn
d
rom
e
(
T
ripl
e
-
X
)
I
n
d
ivi
d
u
a
ls with this syn
d
rom
e
show f
e
m
a
l
e
ph
e
notyp
e
s
,
b
ut
a
t th
e a
g
e
of
22
,
th
e
out
e
r g
e
nit
a
ls
a
r
e
still lik
e a bab
y
.
T
h
e
g
e
nit
a
ls
a
n
d b
r
ea
sts
a
r
e
not w
e
ll
de
v
e
lop
ed
,
a
n
d
th
e
y m
a
y
e
xp
e
ri
e
n
ce
m
e
nt
a
l m
e
nt
a
l
d
isor
de
rs
.
T
h
e
r
e a
r
e a
lso wom
e
n with poly
-
X c
hromosom
e
s
,
su
c
h
a
s
Te
tr
a
-
X a
n
d Pe
nt
a
-
X
.
T
h
e
mor
e c
hromosom
e
s x
,
th
e
low
e
r th
e
l
e
v
e
l of
int
e
llig
e
n
ce a
n
d
th
e
gr
ea
t
e
r th
e
m
e
nt
a
l
d
isor
de
r
.
T
h
e ca
us
e
of th
e
tripl
e
-
x syn
d
rom
e
is non
d
isjun
c
tion wh
e
n forming g
a
m
e
t
b
y moth
e
r
.
X
yy m
a
n
17
Me
n with this syn
d
rom
e
usu
a
lly h
a
v
e a
v
e
ry high h
e
ight
(
183
c
m
a
v
e
r
a
g
e
,
whil
e
oth
e
r m
e
n in th
e
s
a
m
e
prison
a
r
e
165
c
m
a
v
e
r
a
g
e
).
T
h
e
ir
IQ
r
a
ng
e
s from
80
-
118
.
T
h
e
y m
a
y h
a
v
e ab
norm
a
liti
e
s in out
e
r
a
n
d
dee
p g
e
nit
a
li
a b
ut not in
b
o
d
y sh
a
p
e
.
XYY
m
e
n oft
e
n show
a
ggr
e
ssiv
e
be
h
a
vior
a
n
d
t
e
n
d
to viol
a
t
e
th
e
l
a
w
.
Beca
us
e
th
e
y h
a
v
e
two y
c
hromosom
e
s
,
non
d
isjun
c
tion o
cc
urs wh
e
n my f
a
th
e
r forms
sp
e
rm
a
tozo
a
.
N
on
d
isjun
c
tion
d
uring
Me
iosis
II
pro
d
u
ce
s sp
e
rm
a
tozo
a
with
c
hromosom
e Y
,
a
n
d
if this sp
e
rm
a
tozo
a
f
e
rtiliz
e
s th
e e
gg
(
whi
c
h
ca
rri
e
s x
),
zigot xyy will
be
form
ed
.
Q
u
e
stions
a
n
d d
is
c
ussion
I
s th
e
r
e a
s
e
x
c
h
a
ng
e
from wom
e
n to
be
m
a
l
e d
uring
ad
ulthoo
d
?
W
h
a
t
is th
e
r
ea
son
?
Ge
n
de
r
c
h
a
ng
e ca
n o
cc
ur
,
on
e
of whi
c
h is th
e
ps
e
u
d
o
He
rm
a
phro
d
itism
.
A
n
e
x
a
mpl
e
is th
e ca
s
e
of
A
gustin
a
,
who w
a
s
b
orn
a
s
a
wom
a
n
,
b
ut
a
ft
e
r pu
be
rty h
e
r g
e
nit
a
ls
c
h
a
ng
ed
.
T
h
e c
hromosom
e
turn
ed
out to
be a
m
a
n
,
e
v
e
n though
a
t first h
e
look
ed a
wom
a
n
.
I
s th
e
r
e a d
iff
e
r
e
n
ce
in prog
e
st
e
ron
e
l
e
v
e
ls in th
e
f
e
tus with g
e
n
de
r
c
hromosom
e
is not norm
a
l
?
P
rog
e
st
e
ron
e
is
a
n import
a
nt hormon
e
for wom
e
n
d
uring pu
be
rty
,
m
e
nstru
a
tion
,
a
n
d
pr
e
gn
a
n
c
y
.
He
pl
a
ys
a
rol
e
in thi
c
k
e
ning th
e
ut
e
rin
e
w
a
ll
,
stimul
a
ting
b
r
ea
st growth
,
str
e
ngth
e
ns p
e
lvi
c
w
a
lls
,
a
n
d
pr
e
v
e
nts
inf
ec
tion
.
P
rog
e
st
e
ron
e
short
a
g
e
s
ca
n in
c
r
ea
s
e
th
e
risk of mis
ca
rri
a
g
e
a
n
d b
r
ea
stf
eed
ing
d
iffi
c
ulti
e
s
.
P
rog
e
st
e
ron
e
l
e
v
e
ls
d
o not
a
lw
a
ys
de
t
e
rmin
e
th
e
ov
e
r
a
ll pr
e
gn
a
n
c
y
c
on
d
itions
.
N
utrition
a
n
d
h
ea
lth
c
h
ec
ks
d
uring pr
e
gn
a
n
c
y
a
r
e
still import
a
nt for m
a
int
a
ining m
a
t
e
rn
a
l
18
a
n
d
f
e
t
a
l h
ea
lth
.
