[[File:Empirical Cycle.svg.png|thumb|250x250px|Empirical cycle - A.D. de Groot]]
Embryology in the Quran is often criticised from a modern, scientific perspective. More
detail is given throughout this article, but the main criticisms are as follows:
# A number of verses collectively demonstrate a belief that the earliest, nutfah stage of development is made of semen, perhaps mixed with a female fluid, which is placed in the womb for a known term, and where it undergoes various stages of development (as also taught by Galen and in the Jewish Talmud). See [[Greek and Jewish Ideas about Reproduction in the Quran and Hadith|this article]] for the most comprehensive explanation and evidence. Futhermore, there is no sign that the author of the Quran was aware of the female egg (ovum).<p>In reality, a single sperm cell penetrates and fuses with the female ovum. This fertilised egg, called a zygote, is then pushed down the fallopian tube for a few days. On the way, cell division begins, and this multi-celled cluster, now called a blastocyst, implants in the uterus (womb).</p># The embryo is then said to be congealed blood. All the classical tafsirs (commentaries) understood the meaning of 'alaqah to be blood or congealed blood, and clotted blood is a definition of the word in classical Arabic dictionaries. Regardless of alternative meanings for this arabic word, it would be very foolish even to use a word whose main definitions include an explicit biological meaning (clotted blood) in a description of a biological process (embryology) if that meaning was not the one you intended. The choice of word now causes a well justified suspicion of inaccuracy, and for centuries misled people into thinking that the embryo is at one stage congealed blood (an actual embryo is at no point blood or a clot of blood). Similarly, for the same reason it would also be foolish to use this word while intending blood clot as a mere visual analogy.# Bones are said to be formed before being clothed with flesh. In fact cartilage models of the bones start to form at the same time as and in parallel with surrounding muscles, and this cartilage is literally replaced with bone.
The author of the Quran described a sequence of stages, which when examined without the false definitions and arbitrary assumptions made by apologists, clearly has no resemblance to the actual development process of a child in the womb, according to critics. Someone with a modern, scientific knowledge of embryology can instead marvel at the exquisite complexity that results from a process of co-ordinated cell differentiation and signalling, encoded in our genetic instruction set by millions of years of evolution.