2023 Author: Anita Thornton | [email protected]. Last modified: 2023-05-22 03:30
You have just learned that you are pregnant and you are already imagining what your baby will look like. But what makes him have daddy's mouth or mommy's eyes?
Pregnancy is an event that may seem magical and a bit left to fate, but it is actually the result of a complex and fascinating process that begins with the union of egg and sperm and which results in the formation of a completely unique new being.
Of course, you would like to know what this little being will look like, if his personality will resemble yours and who he will one day become. If you're like me, you're probably having fun combining your photo with that of your partner using a site like Morph Thing to see the different combinations possible. But what makes our children inherit certain physical traits and personalities from their parents, and even other family members?
When you conceived your baby, he inherited 23 of your chromosomes and 23 of his father's in each of his cells. It is in the cells that its genetic information and the DNA which encodes more than 25,000 characteristics called genes are found. These genesare responsible for defining his physical characteristics and ensuring the functioning of his body. This genetic heritage will make him a unique being, and he will in turn pass it on to his children one day.
If you put all the chromosomes of all your cells and your DNA in a straight line, it would be the distance from the Earth to the Moon about 6,000 times! We still don't know what over 80% of our DNA is for.
Dominant, recessive and codominant genes
As your child will receive two copies of genes from his parents, these genes can then become dominant, recessive or codominant. A dominant gene, even present in a single copy, always imposes its instructions and prevents the other gene from expressing its own, while a recessive gene is expressed only when two copies of the gene are present. In some cases, both copies of the gene can be expressed equally and are then called codominant. This is what happens, for example, in the case of a child where the “small height” gene is codominant with the “large height” gene: he will be a child of average height.
Did you know that the gene that gives blue eyes is recessive? It must therefore be present in two copies for your child to have blue eyes.
Eye color frequency according to parents' eye color
Sometimes a child is born with a certain characteristic that neitherneither of the parents has, as in the case of children who are born with two eyes of different colors for example. This happens during a genetic mutation and only in rare cases. The child will have a 50% chance of transmitting this characteristic to their child since it will now be part of their genetic makeup.