Three Main steps for human sex
determination & differentiation
1-At the genetic level at the time
of gamete fertilization.
2- Differentiation of the gonads
3- Development of the internal
& external genitalia in response
to secretions from the
At the genetic level
•* Very early at the time of fertilization.
•* Male gamete united with female gamete.
•* If the sperm which fertilizes the ovum
is carrying a Y- chromosome, the off spring
will be a boy.
•* While if it is carrying Xchromosome it will be a girl
(By the will of God).
The Holy Quran described these
facts obviously, which were only
known scientifically in the
That He did create in pairs, male
From a seed when lodged
(in its place) (46:45)
Does Man think that he will be left
uncontrolled, (without purpose)?
Was he not a drop of sperm emitted (in lowly form)?
Then did he become a clinging clot;
then did (Allah) make and fashion
(him) in due proportion.
And of it He made two sexes, male and female.
Has not He, (the same), the power to give life
to the dead?
The Gonadal sex
The term sex determination refers to the
development of gonadal sex. the process that
occurs approximately 7 to 8 weeks
gestation in the human fetus
when either testis or ovary
development occurs (Primary
So the primary sex determination
occurs when the premordial gonads(An organ in
animals that produces gametes, especially a testis
` to either testes or ovaries.
The origin and time of formation of the
gonads (primary sex differentiation)
•Before the 7th week, no sex cords are seen in the
morphologically between the male and female
gonads, although the sex of the embryo is
determined since the time of
fertilization Hamilton Boyd
& Mossman. Page 338, 400.
Of the embryo is a male the premordial germ
cells carry XY sex chromosomes - A gene on
the short arm of the Y-chromosome - called
the testis - determining factor (TDF),
stimulate the undifferentiated
gonads into a testis.
The Prophet Mohammad (peace be upon him) said
:”When the Nutfa enters the womb and stays there
forty nights ,God sends an angel to give it is formand
creates its hearing , visual apparatus , skin , bone and
flesh . Then he asks : O God , is it a boy or a girl ? And
God determines whatever He decides .
“ Narrated by Muslim
(Kitab Al Qadar).
*The testis develops on the posterior abdominal wall
opposite the first lumbar vertebra, later it descends to the
scrotum pulling after it the testicular artery of the
•The testis descends till it reaches the deep
inguinal ring in the 3rd month.
•The testis reaches the
scrotum in the 8th month.
* The ovary also develops on the posterior abdominal
wall opposite the first lumbar vertebra.
Descent of the ovary:
The ovary reaches the false pelvis in 3rd month and
the true pelvis shortly after birth.
•As the ovary descends,
it pulls the ovarian artery
from the abdominal aorta.
The above mentioned Quaranic Ayes states clearly the site of
formation of human gonads.
The commentators of the Holy Quran differed in their
explanation of this aye into two main groups.
The first group includes the majority of the old commentators
like Ibn Jarrir El Tabri, Ibn Kathir, Tafsir El Galalain
who understood that the semen (male
secretion) comes from the bones
if the back and the female part
comes from the ribs or breast.
Ibn El Qaiem refused this explanation. He stated that
the word between means that the vertebral column &
ribs lie in the same person either male or female
(Ilam Al Mowoquin) volume
Al Qurtobi, Al Oloosi, said that the Quaranic ayes are
clear in indicating that both the male & female sexual
gonads come from a place in between
the bones of the back and
It is important to notice that the nerve supply the
blood supply and the lymph drainage remains in the
whole life of the human individual connected to the
area cited in the Holy Quran as between
the vertebral column and
The testicular artery comes from the abdominal aorta
at the level of the second limber vertebra. The right
testicular vein drains into the I.V.C while the left drains
into the left renal veins.
The anatomical & embryological data greatly help in
under standing the facts mentioned in Holy - Quran
and the sayings of prophet Mohammed
(peace be upon him).
These facts mentioned in Quran and Hadith precede
the scientists by more than one thousand year.
Prophet Mohammed (peace be upon him)
mentioned since more than 1400 years
very accurate statements.
* At the sixth week the cloaca is subdivided by a septum
into two parts:
the urogenital and anal membranes. Mean while
genital swellings become visible
on each side of the urethral
•At the sixth week the cloaca is subdivided by a
septum into two parts: the urogenital and anal
membranes. Mean while genital swellings
become visible on each
side of the urethral fold.
By the end of the sixth week the external genitalia
of both male and female are identical and it is
impossible to distinguish between
the two sexes (1).
The differentiation of the external genitalia starts after
the sixth week. It goes on slowly so that by the twelfth
week it becomes relatively easy to recognize
the male from the female.
This again emphasizes the importance of the
aforementioned hadith of the prophet Mohammed
(peace be upon him) which was narrated by
Muslin, whereby the angel enters the womb at 40th –
49 th day and asked “O God, is it a boy or
a girl and God determines
whatever He decides”
Certainly the study of these Quranic ayes (verses)
and the sayings of the prophet Mohammed
(peace be upon him) in the light of scientific
knowledge of modern science give
a better understanding
for these scriptures.
It is also clear that such pristine knowledge
which was revealed fourteen centuries ago, was
beyond the capacity of any mortal to group at