T
h
e Ge
n
e
ti
c
s
Pa
p
e
r
B
ios
c
i
e
n
ce
i
BedRad
for
d H
.
6186382
Tab
l
e
of
c
ont
e
nts
T
itl
e
p
a
g
e
P
r
e
f
ace
Tab
l
e
of
c
ont
e
nts
C
h
a
pt
e
r i
I
.
Bac
kgroun
d
II
.
P
ro
b
l
e
m formul
a
tion
III
.
P
urpos
e
C
h
a
pt
e
r
II
D
is
c
ussion
C
h
a
pt
e
r
III
C
on
c
lusion
Re
f
e
r
e
n
ce
s
P
r
e
limin
a
ry
I
.
Bac
kgroun
d
L
ong
be
for
e Me
n
de
l formul
a
t
ed
g
e
n
e
ti
c
l
a
w
,
th
e c
ommunity h
ad a
n
intuitiv
e
un
de
rst
a
n
d
ing of inh
e
rit
a
n
ce
prop
e
rti
e
s
.
T
h
e
m
a
rri
a
g
e
is
a
voi
ded a
n
d
th
e c
hoi
ce
of
ca
r
e
ful p
a
rtn
e
rs
ba
s
ed
on f
a
mily history is
a
r
ea
l
e
x
a
mpl
e
of th
e
a
ppli
ca
tion of th
e c
on
ce
pt of g
e
n
e
ti
c
s in
e
v
e
ry
da
y lif
e
.
T
h
e a
im is
c
l
ea
r
:
m
a
int
a
ining th
e
qu
a
lity of offspring
a
n
d a
voi
d
ing th
e e
m
e
rg
e
n
ce
of
c
ong
e
nit
a
l
de
f
ec
ts
.
II
.
P
ro
b
l
e
m formul
a
tion
1
.
W
h
a
t is th
e
fun
c
tion of g
e
n
e
ti
c
s
?
2
.
H
ow
ca
n
Me
n
de
l
'
s l
e
g
a
l l
a
w
be ab
l
e
to
d
o it
?
3
.
W
h
a
t
a
r
e
th
e
p
a
rt of th
e c
hromosom
e
?
4
.
H
ow
d
o
I
ov
e
r
c
om
e
h
e
r
ed
it
a
ry
d
is
ea
s
e
in g
e
n
e
ti
c ab
norm
a
liti
e
s
?
III
.
P
urpos
e
T
his p
a
p
e
r is m
ade
to
e
xpl
a
in th
e
g
e
n
e
s in hum
a
ns
.
We
will l
ea
rn
ab
out
sm
a
ll p
a
rts of g
e
n
e
s
,
th
e
prop
e
rti
e
s th
a
t
a
r
e de
riv
ed
from p
a
r
e
nts
,
a
n
d
sym
b
ols
us
ed
to l
ea
rn it
.
T
h
e a
im is th
a
t w
e ca
n un
de
rst
a
n
d
our own prop
e
rti
e
s
a
n
d
living
things
a
roun
d
us
.
I
n
add
ition
,
w
e
will
a
lso
d
is
c
uss
d
is
ea
s
e
s
ca
us
ed b
y g
e
n
e
s
a
n
d
how to ov
e
r
c
om
e
th
e
m
.
D
is
c
ussion
Ge
n
e
ti
c
s
Ge
n
e
ti
c
s is
a
stu
d
y of how
b
iologi
ca
l prop
e
rti
e
s
a
r
e
r
ed
u
ced a
n
d
v
a
ri
ed
in
a
ll forms of lif
e
.
Ge
n
e
ti
c
fun
c
tion
T
h
e
stu
d
y of hum
a
n g
e
n
e
ti
c
s is v
e
ry import
a
nt to l
ea
rn for s
e
v
e
r
a
l r
ea
sons
,
n
a
m
e
ly
:
1
.
S
o th
a
t w
e ca
n un
de
rst
a
n
d
th
e
tr
a
its of our own
de
s
ce
n
da
nts
a
n
d
oth
e
r
living things
a
roun
d
us
.
2
.
T
o fin
d
out th
e ab
norm
a
liti
e
s or
d
is
ea
s
e
s th
a
t
a
r
e
inh
e
rit
ed a
n
d
fin
d
w
a
ys
to ov
e
r
c
om
e
th
e
m
.
3
.
T
o stu
d
y
a
p
e
rson
'
s
de
s
ce
n
da
nts
,
su
c
h
a
s
b
loo
d
typ
e
,
whi
c
h m
a
y
be
n
eeded
in
e
v
e
ry
da
y lif
e
.
Ma
st
e
ring
Ge
n
e
ti
c P
rin
c
ipl
e
s is
a
lso import
a
nt to
stu
d
y th
e
psy
c
hi
a
tri
c
n
a
tur
e
or n
e
rv
e
s of som
e
on
e
who is influ
e
n
ced b
y
offspring
,
su
c
h
a
s
e
x
ce
ss
c
hromosom
e
s th
a
t
ca
n
be
r
e
l
a
t
ed
to m
e
nt
a
l
d
isor
de
rs
,
a
sso
c
i
aca
l
be
h
a
vior
,
a
n
d c
rimin
a
l
ac
ts
.
Ge
n
e
Ge
n is th
e
sm
a
ll
e
st unit of
dec
r
ea
sing prop
e
rti
e
s
,
intro
d
u
ced b
y
W
.
J
oh
a
ns
e
n in
1909
r
e
pl
ac
ing th
e
t
e
rms of th
e de
s
ce
n
da
nts of
G
r
e
gor
Me
n
de
l
.
Me
n
de
l
a
ssum
e
s th
a
t th
e
n
a
tur
e
is inh
e
rit
ed b
y
a
p
a
rti
c
ul
a
r m
a
t
e
ri
a
l
ca
ll
ed
'
f
ac
tor
'.
I
n
1910
,
T
hom
a
s
H
unt
M
org
a
n foun
d
th
a
t g
e
n
e
s w
e
r
e
in
c
hromosom
e
s
.
Ge
n
r
e
gul
a
t
e
s th
e c
h
a
r
ac
t
e
risti
c
s of th
e b
o
d
y through prot
e
in synth
e
sis
,
su
c
h
a
s
k
e
r
a
tin for skin
a
n
d ac
tin
a
n
d
myosin for mus
c
l
e
s
.
Ge
n
e
s
a
r
e
stor
ed
in
c
hromosom
e
s in lo
ca
tions
ca
ll
ed
lo
c
us
e
s
.
Eac
h
c
hromosom
e
h
a
s m
a
ny g
e
n
e
s
th
a
t
c
ont
a
in g
e
n
e
ti
c
inform
a
tion
.
T
h
e
r
e
for
e
,
eac
h
c
hromosom
e
h
a
s
a
row of lo
c
us
e
s in th
e c
hromon
e
m
a
.
L
o
ca
tions
be
tw
ee
n lo
c
us
e
s
a
r
e
not
c
l
ea
r lik
e b
ox
e
s
.
I
n
1869
,
DNA
w
a
s foun
d
only
on
c
hromosom
e
s
,
b
ut it w
a
s not y
e
t known th
a
t
DNA
w
a
s r
e
l
a
t
ed
to g
e
n
e
s
.
O
sw
a
l
d A
v
e
ry
(
1943
)
a
n
d A
lfr
ed He
rsh
e
y
a
n
d Ma
rth
a C
h
a
s
e
(
1953
)
show
ed
th
a
t
DNA
w
a
s g
e
n
e
ti
c
m
a
t
e
ri
a
l
.
T
h
e
g
e
n
e
s
c
onsist of
ADN
who w
e
r
e
ins
e
p
a
r
ab
l
e a
n
d
ti
ed b
y prot
e
ins
,
so th
a
t g
e
n
e
ti
c
m
a
t
e
ri
a
ls w
e
r
e ca
ll
ed a
n
d
.
Ge
n works for
:
1
.
Ma
n
a
g
e
th
e de
v
e
lopm
e
nt
a
n
d
m
e
t
ab
olism of in
d
ivi
d
u
a
ls
2
.
De
liv
e
r g
e
n
e
ti
c
inform
a
tion
be
tw
ee
n g
e
n
e
r
a
tions
3
.
Bec
om
e a
sm
a
ll p
a
rt in
c
hromosom
e
s
4
.
Ha
v
e a
sp
ec
i
a
l pl
ace
in
c
hromosom
e
s
Ge
n
e
prop
e
rti
e
s
a
r
e
:
-
T
h
e
r
e
is
a c
hromosom
e
-
C
ont
a
ins g
e
n
e
ti
c
inform
a
tion
-
Ca
n
d
ou
b
l
e
yours
e
lf wh
e
n th
e ce
ll
d
ivi
de
s
-
Eac
h g
e
n
e
h
a
s
d
iff
e
r
e
nt t
a
sks
a
n
d
fun
c
tions
-
de
t
e
rmin
ed b
y nitrog
e
n
ba
s
e a
rr
a
ng
e
m
e
nts
Ge
n
e
sym
b
ols
:
1
.
T
h
e d
omin
a
nt g
e
n
e
:
g
e
n
e
s th
a
t
c
ov
e
r oth
e
r g
e
n
e
s
a
n
d a
r
e
usu
a
lly writt
e
n in
upp
e
r
ca
s
e
l
e
tt
e
rs
,
for
e
x
a
mpl
e A
.
2
.
Re
s
e
ssiv
e
g
e
n
e
s
:
g
e
n
e
s th
a
t
a
r
e
losing to th
e d
omin
a
nt
a
n
d
un
e
xpris
ed
g
e
n
e
s
,
for
e
x
a
mpl
e a
.
3
.
He
t
e
rozygous g
e
n
e
s
:
c
om
b
in
a
tion g
e
n
e
s of sp
e
rm
ce
lls
(
a
)
a
n
d e
gg
ce
lls
(
a
).
4
.
d
omin
a
nt homozygous g
e
n
e
s
:
two
d
omin
a
nt g
e
n
e
s from m
a
l
e a
n
d
f
e
m
a
l
e
g
e
nit
a
ls
,
for
e
x
a
mpl
e AA
.
5
.
Ge
n
H
omozygot r
ece
ssiv
e
:
two g
e
n
e
r
ece
ssiv
e
from two g
e
nit
a
l
ce
lls
,
for
e
x
a
mpl
e AA
.
6
.
H
omologist
:
c
hromosom
e
s from f
e
m
a
l
e
p
a
r
e
nt simil
a
r to
c
hromosom
e
s from
th
e
m
a
l
e
p
a
r
e
nt
.
7
.
Fe
notyp
e
:
th
e de
s
ce
n
da
nts th
a
t
a
r
e
s
ee
n in
F
1
,
F
2
,
a
n
d F
3
su
c
h
a
s high
,
low
,
c
olor
,
a
n
d
sh
a
p
e
s
.
8
.
Ge
notyp
e
s
:
T
h
e
n
a
tur
e
of th
e de
s
ce
n
da
nts th
a
t
a
r
e
not visi
b
l
e
,
for
e
x
a
mpl
e
AA
,
AA
,
a
n
d AA
.
Dec
r
ea
s
ed
n
a
tur
e
(
He
r
ed
ity
)
T
h
e
pro
b
l
e
m of
dec
r
ea
sing prop
e
rti
e
s
(
h
e
r
ed
ity
)
a
ttr
ac
ts th
e a
tt
e
ntion of
m
a
ny r
e
s
ea
r
c
h
e
rs
.
G
r
e
gor
J
oh
a
nn
Me
n
de
l
,
b
orn in
1822
in
C
z
ec
hoslov
a
ki
a
,
is th
e
most f
a
mous
.
I
n
1842
,
Me
n
de
l
be
g
a
n r
e
s
ea
r
c
hing
a
n
d d
is
c
ov
e
ring th
e ba
si
c
s of
h
e
r
ed
ity
.
He
foun
d
th
e
prin
c
ipl
e
of inh
e
rit
a
n
ce
through
a
tri
a
l of
c
ross
b
r
eed
ing
.
T
h
e
r
e
sult is th
e
l
a
w of
Me
n
de
l
I a
n
d II
.
Me
n
de
l p
e
rforms monohi
b
ri
d c
ross
e
s to s
ee
th
e
inh
e
rit
a
n
ce
p
a
tt
e
rn of th
e
tr
a
it from th
e e
l
de
rs to th
e
n
e
xt g
e
n
e
r
a
tion
.
T
h
e
l
a
w of
Me
n
de
l
I
st
a
t
ed
th
a
t th
e
a
l
e
l p
a
ir
c
oul
d
s
e
p
a
r
a
t
e
fr
ee
ly wh
e
n th
e
form
a
tion of g
a
m
e
t
ce
lls
.
D
isiff
c
ross
e
s
show th
a
t g
e
n
e
s
a
r
e
group
ed
fr
ee
ly wh
e
n forming g
a
m
e
t
e
s
,
acc
or
d
ing to th
e
l
a
w
of
Me
n
de
l
II
.
C
ross
ed c
ross
e
s pro
d
u
ce
f
e
notypi
ca
l
c
omp
a
risons
F
2 9
:
3
:
3
:
1
.
Me
n
de
l
I La
w
(
Ge
n
e Se
p
a
r
a
tion
)
a
n
d La
w
Me
n
de
l
II
(
grouping of fr
ee
g
e
n
e
s
)
prov
e
s th
a
t g
e
n
e
s
a
r
e
inh
e
rit
ed
from p
a
r
e
nts to
c
hil
d
r
e
n through g
a
m
e
t
e
s
.
M
onohi
b
ri
de c
ross
e
s p
a
y
a
tt
e
ntion to on
e d
iff
e
r
e
nt prop
e
rti
e
s
,
whil
e d
il
a
tri
d
i
c
p
a
y
a
tt
e
ntion to two
d
iff
e
r
e
nt prop
e
rti
e
s
,
a
n
d
pro
d
u
ce
four typ
e
s of ph
e
notyp
e
s
with
a
r
a
tio of
9
:
3
:
3
:
1
.
S
om
e
tim
e
s th
e
r
e
is
a de
vi
a
tion
d
u
e
to g
e
n
e
s or g
e
n
e
int
e
r
ac
tions or g
e
n
e
hom
a
zigot l
e
t
a
l
.
T
his l
a
w
c
onsists of two p
a
rts
:
1
.
Le
g
a
l s
e
p
a
r
a
tion
(
s
e
gr
e
g
a
tion
)
F
rom
Me
n
de
l
,
a
lso known
a
s
Me
n
de
l
'
s first l
a
w
,
a
n
d
2
.
La
w in p
a
iring fr
ee
ly
(
I
n
de
p
e
n
de
nt
A
ssortm
e
nt
)
F
rom
Me
n
de
l
,
a
lso known
a
s
T
h
e
s
ec
on
d
l
a
w of
Me
n
de
l
.
Se
gr
e
g
a
tion
La
w
(
Me
n
de
l
I La
w
)
C
omp
a
rison
be
tw
ee
n
B
(
C
ho
c
ol
a
t
e
),
B
(
W
hit
e
),
S
(
short oxt
a
il
),
a
n
d S
(
L
ong
B
untut
)
in th
e F
2
g
e
n
e
r
a
tion
.
T
h
e
fr
ee
s
e
gr
e
g
a
tion l
a
w st
a
t
e
s th
a
t on th
e
form
a
tion of
g
a
m
e
t
,
b
oth p
a
r
e
nt g
e
n
e
s will s
e
p
a
r
a
t
e
so th
a
t
e
v
e
ry g
a
m
e
t r
ece
iv
e
s on
e
g
e
n
e
.
T
his l
a
w in
c
lu
de
s thr
ee
m
a
in points
:
1
.
Ge
n
e
h
a
s
a
n
a
lt
e
rn
a
tiv
e
form th
a
t r
e
gul
a
t
e
s
c
h
a
r
ac
t
e
r v
a
ri
a
tions
,
n
a
m
e
ly
d
omin
a
nt
a
ll
e
l
e
s
(
a
pp
ea
rs from outsi
de
,
upp
e
r
ca
s
e
l
e
tt
e
rs lik
e
r
)
a
n
d
r
e
s
e
ssiv
e a
ll
e
l
e
s
(
not
a
lw
a
ys looks
,
sm
a
ll l
e
tt
e
rs lik
e
w
).
2
.
E
v
e
ry in
d
ivi
d
u
a
l
ca
rri
e
s
a
p
a
ir of g
e
n
e
s
,
on
e
of th
e
m
a
l
e e
l
de
rs
(
lik
e WW
)
a
n
d
on
e
of th
e
f
e
m
a
l
e e
l
de
rs
(
lik
e RR
).
3
.
I
f this p
a
ir of g
e
n
e
s is
d
iff
e
r
e
nt
(
SB a
n
d SB
),
th
e d
omin
a
nt
a
ll
e
l
e
(
S
or
B
)
will
a
lw
a
ys
be e
xpr
e
ss
ed
,
whil
e
th
e
r
e
s
e
ssiv
e a
ll
e
ys
(
S
or
B
)
r
e
m
a
in inh
e
rit
ed b
ut not
a
lw
a
ys
a
pp
ea
r
.
F
r
ee A
sort
a
tion
La
w
(
Me
n
de
l
II La
w
)
T
h
e
s
ec
on
d
l
a
w of
Me
n
de
l s
a
i
d
th
a
t th
e
prop
e
rti
e
s w
e
r
e
low
e
r
ed
fr
ee
ly
,
m
ea
ning
a
ll
e
l
e
s for on
e
tr
a
it
d
i
d
not
a
ff
ec
t
a
ll
e
l
e
ts for oth
e
r prop
e
rti
e
s
.
F
or
e
x
a
mpl
e
,
pl
a
nt
h
e
ight
a
n
d
flow
e
r
c
olor
d
o not influ
e
n
ce eac
h oth
e
r
.
I
n th
e e
x
a
mpl
e
,
a
whit
e
m
a
l
e
p
a
r
e
nt
(
WW
g
e
notyp
e
)
a
n
d
th
e
r
ed
f
e
m
a
l
e
p
a
r
e
nt
(
Ge
notyp
e RR
)
pro
d
u
ce
s first
offspring
a
ll of th
e
m
a
r
e be
r
e
notyp
e
wr
.
T
h
e c
rossing of th
e
first
de
s
ce
nt
pro
d
u
ce
s in
d
ivi
d
u
a
ls with th
e Ge
notyp
e
of
RR
,
RW
,
RW
,
a
n
d WW
in th
e
n
e
xt
g
e
n
e
r
a
tion
,
with
a c
omp
a
rison of r
ed a
n
d
whit
e
ph
e
notyp
e
s
3
:
1
.
F
igur
e
1
shows th
e c
rossing of monohi
b
ri
d
with on
e d
omin
a
nt tr
a
it
,
whil
e F
igur
e
2
shows
a c
ross
ed c
ross with two
d
omin
a
nt tr
a
its
:
th
e
form of oxt
a
il
a
n
d
skin
c
olor
.
I
n
F
igur
e
2
,
g
a
m
e
t
e
s from th
e
m
a
l
e
p
a
r
e
nt
a
r
e SB a
n
d SB
,
whil
e
th
e
f
e
m
a
l
e
p
a
r
e
nt
is
SB a
n
d SB
.
T
h
e
r
e
sults of
F
1
c
ross
e
s
a
ll h
a
v
e SSBB
g
e
notyp
e
s
.
I
f
F
1
is m
a
t
ed
a
g
a
in
,
I
n
d
ivi
d
u
a
l
F
2
will
be
form
ed
with
16
possi
b
l
e
g
e
notyp
e
s
,
two forms of oxt
a
il
(
short or long
)
a
n
d
two skin
c
olors
(
b
rown or whit
e
).
C
omp
a
rison of
b
rown
c
olor
:
W
hit
e
is
12
:
4
a
n
d a
short oxt
a
il form
:
l
e
ngth is
a
lso
12
:
4
.
C
omp
a
rison of g
e
notyp
e
s
is
1
:
2
:
2
:
4
:
1
:
2
:
1
:
1
:
1
.
C
hromosom
e
T
h
e c
hromosom
e
is
c
hrom
a
tin th
a
t short
e
ns
a
n
d e
nl
a
rg
e
s wh
e
n th
e ce
ll
d
ivi
de
s
,
so it
ca
n
be
s
ee
n un
de
r
a
mi
c
ros
c
op
e
.
T
h
e c
hromosom
e c
om
e
s from th
e
wor
d
"
c
hrom
a
"
whi
c
h m
ea
ns
c
olor
a
n
d
"
SOMA
"
whi
c
h m
ea
ns th
e b
o
d
y
.
C
hromosom
e
s
a
r
e
in th
e ce
ll
'
s nu
c
l
e
us
a
n
d
sh
a
p
ed
st
e
ms or
c
rook
ed
.
Wa
l
de
y
e
r intro
d
u
ced
th
e
t
e
rm
c
hromosom
e
in
1888
,
a
lthough
F
l
e
mming h
ad
s
ee
n it in
1879
.
R
oux
(
1887
)
not
ed
th
a
t th
e
num
be
r of
c
hromosom
e
s
d
iff
e
r
be
tw
ee
n sp
ec
i
e
s
a
n
d
r
e
m
a
in th
e
s
a
m
e
throughout th
e
lif
e
,
a
n
d M
org
a
n
(
1993
)
foun
d
his rol
e
in inh
e
rit
a
n
ce
g
e
n
e
ti
c
.
O
th
e
r
e
xp
e
rts su
c
h
a
s
He
itz
(
1935
)
a
n
d K
uw
a
n
da
n
(
1939
)
added
inform
a
tion
ab
out th
e c
hromosom
e
form
.
C
hromosom
e
morphology
C
hromosom
e
s
a
r
e c
l
ea
rly visi
b
l
e
wh
e
n nu
c
l
e
us
d
ivi
de a
n
d
us
e
sp
ec
i
a
l
st
a
ining
.
A
t this tim
e
,
c
hromosom
e
s shrink
a
n
d
thi
c
k
e
r
,
so it
'
s
ea
si
e
r to
ab
sor
b
c
olors
.
T
h
e
siz
e
of th
e c
hromosom
e
v
a
ri
e
s
be
tw
ee
n sp
ec
i
e
s
,
a
l
e
ngth of
0
.
2
-
50
mi
c
rons
,
th
e d
i
a
m
e
t
e
r of
0
.
2
-
20
mi
c
rons
,
a
n
d
in hum
a
ns is
a
roun
d
6
mi
c
rons
.
C
hromosom
e
O
n
e c
hromosom
e c
onsists of two p
a
rts
:
1
.
Se
ntrom
a
ir
e
:
T
h
e c
hromosom
e
h
ead
th
a
t s
e
rv
e
s
a
s
a
pl
ace
for pl
a
sm
a
thr
ead
gr
a
nts in
a
n
a
ph
a
s
e
,
a
n
d d
o
e
s not
c
ont
a
in
c
hromon
e
m
a
or g
e
n
e
s
.
2
.
A
rms
:
c
hromosom
e b
o
d
y p
a
rts
c
ont
a
ining
c
hromon
e
m
a a
n
d
g
e
n
e
s
,
with thr
ee
r
e
gions
:
-
m
e
m
b
r
a
n
e
:
thin l
a
y
e
r
c
ov
e
ring th
e c
hromosom
e
.
-
Ma
trix
:
C
l
ea
r liqui
d
in th
e a
rm
.
-
C
hromon
e
m
a
:
fin
e
thr
ead
in th
e
siology origin
a
ting from
c
hrom
a
tin
,
with
c
hromom
e
rs
(
whi
c
h
a
r
e
not
c
l
ea
r to hum
a
ns
).
C
hromosom
e a
rm
See
ing th
e d
iff
e
r
e
n
ce
in th
e ab
sorption of
c
olor
,
E
.
He
rtz
(
1928
)
d
istinguish
c
hrom
a
tin into two typ
e
s
:
1
.
He
t
e
ro
c
hrom
a
tin
:
th
e c
hrom
a
tin
a
r
ea
th
a
t
ab
sor
b
s mor
e c
olor
su
b
st
a
n
ce
s
.
2
.
E
ukrom
a
tin
:
th
e b
right
c
hrom
a
tin
a
r
ea a
n
d c
ont
a
ins
ac
tiv
e
g
e
n
e
s
.
He
t
e
ro
c
hrom
a
tin is spr
ead be
tw
ee
n
e
ukrom
a
tin
,
e
sp
ec
i
a
lly n
ea
r th
e
ce
ntrom
a
ir
.
He
t
e
ro
c
hrom
a
tin
ca
n turn into
e
ukrom
a
tin wh
e
n g
e
n
e
s
bec
om
e ac
tiv
e
,
a
n
d
vi
ce
v
e
rs
a
.
Ge
n
e
s
a
r
e
not
a
lw
a
ys
ac
tiv
e
,
de
p
e
n
d
ing
on
ce
ll n
eed
s
.
Ba
s
ed
on th
e
position of th
e ce
ntrom
a
n
d a
rm l
e
ngth
,
th
e c
hromosom
e
is
d
istinguish
ed
into
:
1
.
Me
t
a
s
e
ntri
c
:
ce
ntrom
e
r in th
e
mi
dd
l
e
,
th
e
s
a
m
e a
rm is long
,
sh
a
p
e V
.
2
.
S
u
b
m
e
t
a
s
e
ntri
c
:
T
h
e ce
ntrom
e
r is
a b
it to tip
,
th
e a
rm is not th
e
s
a
m
e
l
e
ngth
,
J
.
S
h
a
p
e
.
3
.
A
kro
ce
ntri
c
:
Ce
ntrom
e
r n
ea
r th
e
tip
,
on
e a
rm is v
e
ry short
,
v
e
ry long
.
4
.
Te
lo
ce
ntri
c
:
Ce
ntrom
e
r
a
t th
e e
n
d
,
only on
e a
rm
,
sh
a
p
e
of th
e
st
e
m
(
not in hum
a
ns
).
C
hromosom
e
typ
e
T
ow
a
r
d
s th
e
20
th
ce
ntury
,
r
e
s
ea
r
c
h
e
rs tri
ed
to know th
e
num
be
r of
c
hromosom
e
s in hum
a
n
b
o
d
y
ce
lls
,
b
ut th
e
r
e
sults w
e
r
e d
iff
e
r
e
nt
beca
us
e
th
e
insp
ec
tion t
ec
hniqu
e
w
a
s still simpl
e
.
I
n
1912
,
W
in
a
w
a
t
e
r s
a
i
d
th
e
r
e
w
e
r
e
47
c
hromosom
e
s
,
b
ut in
1920
Pa
int
e
r s
a
i
d
th
e
r
e
w
e
r
e
48
c
hromosom
e
s
.
T
his
opinion l
a
st
ed
30
y
ea
rs to
1956
,
T
jio
a
n
d Le
v
a
n prov
ed
th
a
t th
e
r
e
w
e
r
e
46
c
hromosom
e
s
.
T
h
e
r
e a
r
e
two typ
e
s of hum
a
n
c
hromosom
e
s
:
1
.
A
utosom
:
O
r
d
in
a
ry
c
hromosom
e
s th
a
t
d
o not
de
t
e
rmin
e
g
e
n
de
r
,
tot
a
ling
44
(
22
p
a
irs
)
of
46
c
hromosom
e
s
.
2
.
G
onosom
e
s
:
Ge
n
de
r
c
hromosom
e
th
a
t
de
t
e
rmin
e
s g
e
n
de
r
,
usu
a
lly
a
p
a
ir
,
c
onsists of
X a
n
d Y c
hromosom
e
s
.
B
loo
d
typ
e
M
ultipl
e a
l
e
l
M
ost g
e
n
e
s in th
e
popul
a
tion h
a
v
e
mor
e
th
a
n two
a
ll
e
l
e
s
.
E
x
a
mpl
e
s of
multipl
e a
ll
e
l
e
s
a
r
e ABO b
loo
d
typ
e
in hum
a
ns
,
whi
c
h h
a
v
e
four ph
e
notyp
e
s
:
A
,
B
,
AB
,
a
n
d O
.
T
h
e
s
e
l
e
tt
e
rs show two typ
e
s of
ca
r
b
ohy
d
r
a
t
e
s
(
A a
n
d B
)
th
a
t
e
xist on
th
e
surf
ace
of r
ed b
loo
d ce
lls
.
B
loo
d
typ
e A a
n
d B ca
n
be
pr
e
s
e
nt
,
tog
e
th
e
r
(
AB
),
or not
a
t
a
ll
(
O
).
T
h
e
suit
ab
ility of
b
loo
d
typ
e
is import
a
nt in
b
loo
d
tr
a
nsfusions to
pr
e
v
e
nt
c
lumps th
a
t
ca
n
be
f
a
t
a
l
.
B
loo
d
typ
e
is
de
t
e
rmin
ed b
y
a c
om
b
in
a
tion of thr
ee a
ll
e
l
e
s
:
it
(
for
ca
r
b
ohy
d
r
a
t
e
s
a
),
IB
(
for
ca
r
b
ohy
d
r
a
t
e
s
B
),
a
n
d I
(
d
o
e
s not pro
d
u
ce
ca
r
b
ohy
d
r
a
t
e
s
a
or
b
).
T
h
e
r
e a
r
e
six possi
b
l
e
g
e
notyp
e
s
.
He a
n
d IB a
ll
e
l
e
s
a
r
e
d
omin
a
nt
a
g
a
inst i
,
so h
e
h
e a
n
d
h
e
i is typ
e a
,
i
b
i
b a
n
d
i
b
i
a
r
e
typ
e b
,
a
n
d
ii is
typ
e
o
.
a
l
e
l h
e a
n
d
i
b
is
c
o
d
omin
a
n
,
so h
e
i
b
is typ
e AB
.
O
-
A
-
B B
loo
d T
yp
e
A
ntig
e
n
A a
n
d B
(
A
glutinog
e
n
)
M
ost p
e
opl
e
h
a
v
e a
ntig
e
ns typ
e A a
n
d B
on th
e
ir r
ed b
loo
d ce
ll surf
ace
.
T
his
a
ntig
e
n is
ca
ll
ed a
glutinog
e
n
beca
us
e
it oft
e
n
ca
us
e
s
b
loo
d ce
ll
a
gglutin
a
tion
a
n
d
trigg
e
rs
a
tr
a
nsfusion r
eac
tion
.
T
his
a
ntig
e
n is g
e
n
e
ti
ca
lly
r
ed
u
ced
,
so som
e
on
e ca
n not h
a
v
e
,
h
a
v
e
on
e
,
or
b
oth
.
O
-
A
-
B B
loo
d T
yp
e
I
n
b
loo
d
tr
a
nsfusion
,
b
loo
d
typ
e d
ivi
ded
into four m
a
in typ
e
s
:
O
,
A
,
B
,
a
n
d
AB
,
ba
s
ed
on th
e
pr
e
s
e
n
ce
of
a
glutinog
e
n
A a
n
d B
.
B
loo
d
typ
e
o
D
o
e
s not h
a
v
e
a
gglutinog
e
ns
,
c
l
a
ss
A
h
a
s
a
gglutinog
e
n
a
,
group
B
h
a
s
a
gglutinog
e
n
B
,
A
n
d
group
AB
h
a
s
b
oth
a
glutinog
e
ns
.
Ge
n
e
ti
c De
t
e
rmin
a
tion
A
glutinog
e
n
O
-
A
-
B b
loo
d
typ
e
is
de
t
e
rmin
ed b
y two g
e
n
e
s in p
a
ir
ed c
hromosom
e
s
.
T
h
e
s
e
g
e
n
e
s
ca
n typ
e O
,
A
,
or
B
.
T
yp
e O Ge
n
e
s
a
r
e
not fun
c
tioning or h
a
r
d
ly
fun
c
tioning
,
whil
e
typ
e A a
n
d B
g
e
n
e
s pro
d
u
ce
strong
a
glutinog
e
ns
.
T
h
e
c
om
b
in
a
tion of th
e
s
e
g
e
n
e
s
(
OO
,
OA
,
OB
,
AA
,
BB
,
AB
)
de
t
e
rmin
e
som
e
on
e
'
s
g
e
notyp
e a
n
d b
loo
d
typ
e
.
A
glutinin
I
f som
e
on
e d
o
e
s not h
a
v
e a
typ
e A a
gglutinog
e
n
,
th
e
pl
a
sm
a
will pro
d
u
ce
a
nti
-
A a
gglutinin
,
a
n
d
if it
d
o
e
s not h
a
v
e a
typ
e B a
glutinog
e
n
,
th
e
pl
a
sm
e
n will
pro
d
u
ce a
nti
-
b a
glutinin
.
B
loo
d
typ
e O c
ont
a
ins
a
nti
-
A a
n
d a
nti
-
B a
glutinin
,
b
loo
d
typ
e A c
ont
a
ins
a
nti
-
b a
glutinin
e
,
b
loo
d
typ
e B c
ont
a
ins
a
nti
-
A a
glutinin
e
,
a
n
d
b
loo
d
typ
e AB d
o
e
s not
c
ont
a
in
a
glutinin
.
A
ntig
e
n inh
e
rit
a
n
ce A a
n
d B
A
ntig
e
n
A a
n
d B
is inh
e
rit
ed a
s
A
l
e
lomorph
Me
n
de
l
a
n
d a
r
e d
omin
a
nt
.
S
om
e
on
e
with
b
loo
d
typ
e B ca
n h
a
v
e a BB
g
e
notyp
e
(
homozygot
)
or
b
o
(
h
e
t
e
rozygot
).
B
y knowing th
e b
loo
d
typ
e
of p
a
r
e
nts
,
w
e ca
n pr
ed
i
c
t th
e
ir
c
hil
d
'
s
g
e
notyp
e
.
B
loo
d
typ
e ca
n
a
lso
be
us
ed
to g
e
t ri
d
of th
e
possi
b
ility of
b
iologi
ca
l
f
a
th
e
rs with
a
lmost
100
%
acc
ur
ac
y using
DNA
'
s s
ec
tion
..
B
loo
d
typ
e
I
n
add
ition to
O
-
A
-
B b
loo
d
typ
e
,
th
e RH
syst
e
m is
a
lso import
a
nt in
b
loo
d
tr
a
nsfusions
.
T
h
e d
iff
e
r
e
n
ce
is th
e a
gglutinin
e
r
eac
tion in th
e RH
syst
e
m
r
a
r
e
ly spont
a
n
e
ously
.
S
om
e
on
e
n
eed
s to
be e
xpos
ed
to
a
n
RH a
ntig
e
n
m
a
ssiv
e
ly
,
for
e
x
a
mpl
e
through
b
loo
d
tr
a
nsfusions or from moth
e
rs to
bab
i
e
s
,
be
for
e
th
e
r
eac
tion o
cc
urs
.
RH a
ntig
e
n
T
h
e
r
e a
r
e
six
RH a
ntig
e
ns
,
n
a
m
e
ly
C
,
D
,
E
,
C
,
D
,
a
n
d E
.
Pe
opl
e
who h
a
v
e
a
ntig
e
n
C d
on
'
t h
a
v
e a
ntig
e
n
C
,
a
n
d
so on
.
T
h
e
most
c
ommon
a
n
d a
ntig
e
ni
c
a
ntig
e
ns
,
so p
e
opl
e
with
a
ntig
e
ns
a
r
e ca
ll
ed RH
-
positiv
e
,
without
a
ntig
e
n
D
ca
ll
ed R
h
-
n
e
g
a
tiv
e
.
Ab
out
85
%
of whit
e
p
e
opl
e a
n
d
95
%
of
A
m
e
ri
ca
n
b
l
ac
k
p
e
opl
e a
r
e RH
-
positiv
e
.
T
h
e e
st
ab
lishm
e
nt of
a
nti
-
rh
a
m
b
utinin
e
I
f som
e
on
e
'
s
R
h
-
n
e
g
a
tiv
e
is inj
ec
t
ed
with
R
h
-
positiv
e b
loo
d
,
his
b
o
d
y will
form
a
n
a
nti
-
rhyglutinin
a
ft
e
r
2
-
4
months
.
I
f it is oft
e
n
e
xpos
ed
,
th
e b
o
d
y will
be
mor
e
s
e
nsitiv
e
to th
e RH
f
ac
tor
.
RH T
r
a
nsfusion
Reac
tion
R
h
-
n
e
g
a
tiv
e
p
e
opl
e
who h
a
v
e
n
e
v
e
r
bee
n
e
xpos
ed
to
RH
-
positiv
e b
loo
d d
o
not imm
ed
i
a
t
e
ly r
eac
t wh
e
n
RH
-
positiv
e b
loo
d
tr
a
nsfusion
.
B
ut
,
a
ft
e
r
2
-
4
w
ee
ks
,
a
nti
b
o
d
i
e
s
ca
n
be
form
ed
whi
c
h
ca
us
e
s slow
a
n
d
light r
eac
tions
.
O
n
th
e
n
e
xt tr
a
nsfusion
,
th
e
r
eac
tion
ca
n
be
strong
e
r
a
n
d
h
ea
vi
e
r
.
B
loo
d
typ
e M
,
N
,
a
n
d MN
Ba
s
ed
on two mol
ec
ul
e
s on th
e
surf
ace
of r
ed b
loo
d ce
lls
,
b
loo
d
typ
e M
,
N
,
a
n
d MN a
r
e de
t
e
rmin
ed b
y
a
ll
e
l
e
s on
a
singl
e
g
e
n
e
lo
c
us
.
I
n
d
ivi
d
u
a
ls m
homozygous for on
e a
ll
e
l
e
,
in
d
ivi
d
u
a
l n for oth
e
r
a
ll
e
l
e
ts
,
a
n
d
in
d
ivi
d
u
a
ls mn
h
e
t
e
rozygot with
b
oth mol
ec
ul
e
s
.
A
ll
e
l
e
A
ll
e
l
e
s
a
r
e a
n
a
lt
e
rn
a
tiv
e
form of g
e
n
e
s th
a
t
de
t
e
rmin
e
th
e
ph
e
notyp
e
.
F
or
e
x
a
mpl
e
,
a
ll
e
l
e
s for r
ed
or whit
e
flow
e
rs
.
A
t furth
e
r l
e
v
e
ls
,
a
ll
e
l
e
s
ca
n
a
lso
m
ea
n v
a
ri
a
tion of
DNA
,
RNA
,
or prot
e
in
.
Ge
n
e
ti
c d
isor
de
rs
a
n
d d
is
ea
s
e
s
Ge
n
e
ti
c d
is
ea
s
e
s
a
r
e ca
us
ed b
y no fun
c
tion
.
D
isor
de
rs
ca
n
be d
u
e
to
a
utosom
a
l
d
omin
a
nt
a
ll
e
l
e
s
,
a
utosom
a
l r
ece
ssiv
e
s
,
or link
ed
with s
e
x
c
hromosom
e
s
,
a
n
d
th
e
influ
e
n
ce
of
c
hromosom
e abe
rr
a
tion
.
A
utosom
a
l r
ece
ssiv
e a
l
e
l
bac
i
e
s
Ge
n
e
ti
c
g
e
n
e a
n
d ab
norm
a
liti
e
s
Eac
h g
e
n
e e
n
c
o
de
s prot
e
ins with
ce
rt
a
in fun
c
tions
.
A
ll
e
l
e
s th
a
t
ca
us
e
g
e
n
e
ti
c
ab
norm
a
liti
e
s
e
n
c
o
de
prot
e
ins th
a
t
d
o not fun
c
tion or not
e
n
c
o
de
th
e
prot
e
in
a
t
a
ll
.
I
n
r
ece
ssiv
e ab
norm
a
liti
e
s
,
h
e
t
e
rozygous
(
AA
)
d
o
e
s not show symptoms
beca
us
e
norm
a
l
a
ll
e
l
e
s
(
a
)
a
r
e e
nough to pro
d
u
ce
th
e
r
e
quir
ed
prot
e
in
.
Rece
ssiv
e d
is
ea
s
e
s
a
pp
ea
r in th
e
homozygous r
ece
ssiv
e
in
d
ivi
d
u
a
l
(
AA
).
T
h
e
p
a
ti
e
nt g
e
notyp
e
is writt
e
n
a
s
AA
,
a
n
d
norm
a
l g
e
notyp
e a
s
AA
or
AA
.
He
t
e
rozigot
(
AA
)
th
a
t looks norm
a
l is th
e
tr
a
it
ca
rri
e
r
,
beca
us
e
it
ca
n p
a
ss on th
e
r
ece
ssiv
e
g
e
n
e
to his offspring
.
Rece
ssiv
e ab
norm
a
liti
e
s
usu
a
lly
e
m
e
rg
e
from p
a
r
e
nts
'
p
a
r
e
nts
(
AA
x
AA
)
or from m
a
rri
a
g
e
(
AA X AA
)
a
n
d
(
AA X
AA
).
C
r
e
s
ce
nt
ce
ll
a
n
e
mi
a
Ob
it
ce
ll
a
n
e
mi
a
is
ca
us
ed b
y
c
h
a
ng
e
s in on
e a
mino
ac
i
d
in h
e
moglo
b
in prot
e
in
.
I
n low
oxyg
e
n
c
on
d
itions
,
r
ed b
loo
d ce
lls
c
h
a
ng
e
sh
a
p
e
into si
c
kl
e
.
T
h
e
suff
e
r
e
r of si
c
kl
e ce
ll
a
n
e
mi
a
h
a
s
a
g
e
notyp
e
of
SS
,
norm
a
l
SS
,
a
n
d SS ca
r
ee
r
.
C
ysti
c
fi
b
rosis
S
itisti
c
fi
b
rosis is
ca
us
ed b
y th
e ab
s
e
n
ce
of prot
e
in th
a
t h
e
lps tr
a
nsport ion
c
hlori
de
.
T
his pro
d
u
ce
s mu
c
us th
a
t
a
ff
ec
ts th
e
p
a
n
c
r
ea
s
,
r
e
spir
a
tory tr
ac
t
,
a
n
d
sw
ea
t gl
a
n
d
s
.
T
his
d
is
ea
s
e a
pp
ea
rs in th
e CC
g
e
notyp
e
,
whil
e CC a
n
d N
orm
a
l
CC ca
r
ee
r
.
Ga
l
a
ktos
e
mi
a
Ga
l
ac
tos
e
mi
a
is
ca
us
ed b
y th
e
in
ab
ility to
d
ivi
de
g
a
l
ac
tos
e beca
us
e
of th
e ab
s
e
n
ce
of
l
ac
t
a
s
e e
nzym
e
s
.
T
h
e
high g
a
l
ac
tos
e
in th
e b
loo
d ca
n
da
m
a
g
e
th
e e
y
e
s
,
liv
e
r
a
n
d b
r
a
in
.
S
ymptoms of g
a
l
ac
tos
e
mi
a
in
c
lu
de
m
a
lnutrition
,
d
i
a
rrh
ea
,
a
n
d
vomiting
.
Lac
tos
e
-
fr
ee
d
i
e
t
ca
n pr
e
v
e
nt th
e
s
e
symptoms
.
T
h
e
p
a
ti
e
nt g
e
notyp
e
is
GG
,
norm
a
l
GG
,
a
n
d a ca
r
ee
r
GG
.
A
l
b
ino
A
l
b
ino w
a
s
ca
us
ed b
y th
e
in
ab
ility to turn th
e
tyrosin
e
to m
e
l
a
nin
beca
us
e
of th
e
ab
s
e
n
ce
of
e
nzym
e
s
.
N
orm
a
lly
,
Ge
notyp
e AA
or
AA
pro
d
u
ce
s this
e
nzym
e
,
whil
e A
l
b
ino
is
AA
.
P
h
e
nylk
e
tonuri
a
P
h
e
nylk
e
tonuri
a
is
a
h
e
r
ed
it
a
ry
d
is
ea
s
e
wh
e
r
e
p
a
ti
e
nts
ca
nnot m
e
t
ab
oliz
e
ph
e
nyl
a
l
a
nin
e
.
S
ymptoms in
c
lu
de acc
umul
a
t
ed
ph
e
nyl
a
l
a
nin
e
in th
e b
loo
d
,
m
e
nt
a
l r
e
t
a
r
da
tion
,
whit
e
h
a
ir
,
a
n
d a
musty
b
o
d
y o
d
or
.
Pa
ti
e
nts h
a
v
e
phph g
e
notyp
e
s
,
norm
a
l
PHPH
,
a
n
d PHPH
ca
r
ee
rs
.
T
h
a
l
a
ss
e
mi
a
T
h
a
l
a
ss
e
mi
a
is
a
g
e
n
e
ti
c d
isor
de
r with r
ed
u
ced
h
e
moglo
b
in pro
d
u
c
tion
.
T
h
a
l
a
ss
e
mi
a
Ma
jor is v
e
ry s
e
v
e
r
e a
n
d ca
n
ca
us
e
inf
a
nt
dea
th
,
whil
e
th
a
l
a
ss
e
mi
a
minor is light
e
r with
symptoms of slightly spl
ee
n sw
e
lling
.
C
ov
e
r
C
on
c
lusion
Ge
n
e
ti
c
s is
a
s
c
i
e
n
ce
th
a
t stu
d
i
e
s th
e dec
r
ea
s
e
in tr
a
its
.
T
h
e
p
e
rson who is
c
onsi
de
r
ed a
g
e
n
e
ti
c Fa
th
e
r is
G
r
e
gor
Me
n
de
l
.
Ge
n
,
c
ont
a
in
ed
in
c
hromosom
e
s
,
h
a
s
th
e
following qu
a
liti
e
s
:
-
A
s m
a
t
e
ri
a
l in
c
hromosom
e
s
-
C
ont
a
ins g
e
n
e
ti
c
inform
a
tion
-
Ca
n
d
upli
ca
t
e
th
e
ms
e
lv
e
s wh
e
n
ce
ll
d
ivision
-
Ha
v
e d
iff
e
r
e
nt t
a
sks
a
n
d
fun
c
tions
-
de
t
e
rmin
ed b
y nitrog
e
n
ba
s
e c
om
b
in
a
tion
Me
n
de
l st
a
t
ed
th
a
t
e
v
e
ry in
d
ivi
d
u
a
l
b
rought
a
p
a
ir of g
e
n
e
s
,
on
e
of th
e
m
a
l
e e
l
de
rs
a
n
d
on
e
of th
e
f
e
m
a
l
e e
l
de
rs
.
I
f two in
d
ivi
d
u
a
ls h
a
v
e
mor
e
th
a
n on
e
tr
a
it
,
th
e
s
e
prop
e
rti
e
s
a
r
e
fr
ee
.
C
hromosom
e
s
a
r
e
thr
ead
stru
c
tur
e
s in th
e ce
ll
c
or
e
r
e
sponsi
b
l
e
for h
e
r
ed
ity
.
C
hromosom
e
s
a
r
e d
ivi
ded
into two
ba
s
ed
on th
e
ir fun
c
tions
:
1
.
b
o
d
y
c
hromosom
e
(
a
utosom
):
de
t
e
rmin
e
th
e
sh
a
p
e
,
c
h
a
r
ac
t
e
risti
c
,
a
n
d
c
h
a
r
ac
t
e
risti
c
s of th
e b
o
d
y
.
2
.
Ge
n
de
r
c
hromosom
e
:
De
t
e
rmin
e
g
e
n
de
r to in
d
ivi
d
u
a
ls
.
