Until fairly recently, it was thought that a baby’s sex was determined by the mother’s cells. Or at least, it was believed that the sex was determined by the male and female cells together. But, we are given different information in the Qur’an, where it is stated that masculinity or femininity is created out of “a drop of sperm which has been ejected.”
053.045► وَأَنَّهُ خَلَقَ الزَّوْجَيْنِ الذَّكَرَ وَالأنْثَى
053.046► مِنْ نُطْفَةٍ إِذَا تُمْنَى He has created both sexes, male and female from a drop of semen which has been ejected. (Qur’an, An-Najm -53:45-46)
075.037► أَلَمْ يَكُ نُطْفَةً مِنْ مَنِيٍّ يُمْنَى 075.038► ثُمَّ كَانَ عَلَقَةً فَخَلَقَ فَسَوَّى 075.039 ►فَجَعَلَ مِنْهُ الزَّوْجَيْنِ الذَّكَرَ وَالأنْثَى Wasn’t he a drop of ejaculated sperm, then an embryo which He created and shaped, making from it both sexes, male and female? (Qur’an, Al-Qiyama -75:37-39)
The developing disciplines of genetics and molecular biology have scientifically validated the accuracy of this information given by the Qur’an. It is now understood that sex is determined by the sperm cells from the male, and that the female has no role in this process.
Chromosomes are the main elements in determining sex. Two of the 46 chromosomes that determine the structure of a human being are identified as the sex chromosomes. These two chromosomes are called “XY” in males, and “XX” in females, because the shapes of the chromosomes resemble these letters. The Y chromosome carries the genes that code for masculinity, while the X chromosome carries the genes that code for femininity.
The formation of a new human being begins with the cross combination of one of these chromosomes, which exist in males and females in pairs. In females, both components of the sex cell, which divides into two during ovulation, carry X chromosomes. The sex cell of a male, on the other hand, produces two different kinds of sperm, one that contains X chromosomes and the other Y chromosomes. If an X chromosome from the female unites with a sperm that contains an X chromosome, then the baby is female. If it unites with the sperm that contains a Y chromosome, the baby is male.
In other words, a baby’s sex is determined by which chromosome from the male unites with the female’s ovum.
None of this was known until the discovery of genes in the 20th century. Indeed, in many cultures, it was believed that a baby’s sex was determined by the female. That was why women were blamed when they gave birth to girls.
Fourteen centuries before human genes were discovered, however, the Qur’an revealed information that denies this superstition, and referred to the origin of sex lying not with women, but with the semen deriving from men.