The oocyte (egg) is the largest cell in the human body and the only one that can be seen without a microscope. It can be compared to a grain of sand in size.

This female sex cell is not only a set of chromosomes necessary for conception, but also a storehouse of nutrients vital for an embryo to develop. These reserves enable the embryo to survive before it attaches to the uterus to get access to a nutrition source.

The oocyte (egg) is monogamous and picky. Scientists believe that this is not a passive participant in conception and can choose which sperm will win. It allows the candidate with the most worthy DNA to come in. After that, a special organelle creates a barrier to keep other sperm out. Fascinating one!

Egg meets sperm, fertilization occurs, babies are formed. Simple? Not really! Get introduced to the notion of feminine receptivity or the freedom of choice for women. Narrowing it further, the female eggs actually do choose. As believed by Scott Gilbert, developmental biologist at Swarthmore College, the “egg engages in a dialog with the sperm rather than locking it down.” So, fertilization is not actually a conquest, but more like a fair race.

After much research, it has also been proven that eggs tend to attract a particular kind of sperm if given the chance.

Any couple who is planning to extend their family is always under the belief that the sperm races toward the egg. Let’s start at the beginning. All sperm ready, egg at its healthiest, and here begins the race! As we have been taught in school, millions of sperm head towards a single egg cell. When an X meets an X, it’s a girl, and when an X meets a Y, it’s a boy.

So, let’s now begin the process of unlearning.

Female eggs refuse to be submissive. They play a dominant role and choose their own sperm.

Race? Oh wait! It was never a race since the winner has already been decided. In simple language, the egg has already chosen the type of sperm that it will allow to enter.

As researched and explained by scientists, eggs are not submissive and docile, but they play a key player in the process of reproduction. And against the popular notion that sperm races toward the egg, it’s actually the other way around.

As explained by scientists, it’s the egg that favors or discards a sperm, and makes sexual selection at the cellular level itself more complex.

It’s strange but true that such an obvious process was assessed wrongly all this time.


Chara Alatzopoulou

International Patient Coordinator