c Sex determination
The information about sex determination is beautifully narrated in the Qur'an:
وَأَنَّهُ خَلَقَ الزَّوْجَيْنِ الذَّكَرَ وَالأُنْثَى (45). مِنْ نُطْفَةٍ إِذَا تُمْنَى (النجم: 46).
"And He created the two sexes male and female from a drop when ejaculated or planned (Nutfah Idha Tumna) ". (Surah An-Najm, Ayah 45, 46)
"Tumna" in Arabic means "ejaculated" or "planned". "Nutfah Idha Tumna" refers to the sperm when the meaning "ejaculation" is applied and can refer to the formation of the Zygote after the union of the sperm and the ovum, when it is taken to mean "planning" (Ref: 1A, 27/44: 2A, 4/32: 3A, 8/83: 5A, 7/117: 13A, 5/116: 19A, 7/711)
Although participation of an X and Y chromosome bearing sperms determines the sex, the new individual cannot be formed without the ovum. Here the second meaning of "Tumna" (planned or programmed) can be applied. What we know today with regards to sex determination bears out what was revealed in the Qur'an in the 7th century.