Download and for male

‫افراح الطبري‬.‫د‬
Sex Determination _ Sex linkage Inheritance
In the beginning of nineteenth century . the all of clung ,
Sutton and Wilson which seeks to study the chromosomes in
both of male and female this scientist saw the different
between two sex in the structure of chromosomes . they saw
in some in sects for example _Locust _ in the male the number
of chromosomes will be less one chromosome compared with
female in the meiosis division the single chromosome didn’t
nearly with any another chromosome . this chromosome know
or called sex chromosome which in the meiosis division
transport to half number of cell only .
The word sex used to differentiation the different in dividuals
or to differentiation different organs belong to same living
organisms or to differentiation in dividual in different stayes
this differentiation will by compory with able live to
production sex cells or different phesiology gamets . in
general shape we can be divided the different between two sex
to :
1. Primary sexual characters : include the sex organ (gonads
sex ) that product the gamets
2. Secondary sexual characters : include all the traits that
play important role in attraction the sex to another .
Sex determination:
include what must the individual
will be according to genetic structure .
Sex differentiation : include all this
process that lead
to create the different traits in order to different between
the male and female .
( Sex determination according to genotype (sex
chromosomes)
Male
Xo
female
XX
gamets
X
fe
(one chromosomes)
O
X
XY
X
XX
X
Z
ZZ
Z
ma
fe
Y
W
ZW
example
Ma
Locust and
cockroach
human and
Ma
Fe
any mamary
And drosphila
bird .some fish
fowls
The sex differentiation
There are four different stages participantin sex differentiation
process in both human and animal .
1. Sex according to genetics sex : the sex chromosome
structure or female will be (XX) and for male (XY) the genes were
occure on this chromosomes will be determine the sex .
2. Sex according to gonads sex : the chemical
materials that
produced by the embryo cells that has (XX) will be urge to cortical
region to non differentiation gonad and causes growth the overy
tissue .
But on embryo (XY) the chemical material urge to the medulla
region In non differentiation gonads to growth the testes .
3. Sex according to the gantial sex : the sex
embryo gonads
will be produce hormones and this hormones will be limited the
shape of extra organisms sex and sex ducts .
4. Sex according to the somatic sex : the hormones
secretion will be continuous by the some of sex gonads until
appear the second sex characters In adult .
Inheritance related to sex
There are some gentic traits that sex linkage because it is occur
on the sex chromosomes .
The one important traits that study in the chickens is the barred
feathers traits and this trait control by dominance and sex
linkage gene.
EX: when mate between barred female and non barred male
.what is production off spring ‫؟‬
B
P1
G1
Female
ZBW
Zb
W
Z
F1
ZBZb
male
ZbZb
, ZbW
Barred male ,non barred female
 There are genes found on chromosome X only and didn’t
found on chromosome Y ,this genes called sex _ linked
genes this genes will be replicate twice in female and one
in male
Ex : female AA ,Aa ,aa
male AY ,aY
Twice female
just one male
For example of this type of traits is enamel hypoplasia this
trait control by dominant sex _ liked genes . the teeth will by
small size.
 Genes that found on the similar part of both chromosomes
X and Y . this genes called incompletely or partially sex _
linked genes .
The example on this state is total colour blindness .
 The genes occur on chromosome Y only and allele on
chromosome X this type know Y _ linked genes or ltolandric
genes or sex _ limited genes for example : the feather in fowl
will by long and curveturein neck and tail region .
 The dominance between allele in some genes are depend on
sex of individual that has genotype and this genes called
sex_influenced genes . for example : the baldness in human
that control by one pair of genes occur on somatic
chromosomes while In the sheep the horn trait control by
dominance gene in male but the horn less allele will be
dominance in female .
Aberration
XXY
XXX
XXXY
XXY
XXY
Aberration sex chromosomes
living organism
phenotype
cow ,sheep,dogs
less in tissue
Cats
of testis
horse
barrennes
horse
barrenness
human(klinefelter)
barrenness
human(turner)
barrenness
EX : in the sheep the white
wool colour dominance on black colour
and horn dominance on non horn in male ( sex _influnce dominance)
and recessive in female . if we male between sheep pure and white
has horn with female black non horn, what is the first filial and
second filial that production ‫؟‬
Female
P1
male
wwpp
F1
WWPP
WwPp
Horn
PP
horn
PP
Non horn
Pp
horn
Pp
Non horn
pp
non horn pp
Female
P2
male
WwPp
WwPp
3 horn
F2: if male
9white horn
3 white
1 non horn 3white
Non horn
3horn
3 black horn
1 black
1 non horn
1 black
Non horn
If female
3white
3non horn
1horn
9white non horn
3white horn
3non horn
3black non horn
1 black
1horn
1black horn