What happens in the female body during pregnancy, how to use genetics to reveal some of the secrets that nature "hid"?
Any woman preparing to become a mother begins a kind of information itch, forcing her to turn mountains of literature in search of answers to questions related to her interesting position. And this is not surprising: pregnancy is a time when the maternal instinct forces the expectant mother to acquire knowledge about everything related to the correct development of the fetus, normal childbirth, and then caring for the baby. It is then that it becomes interesting what may have been missed in biology lessons.
Where is the code stored to ensure that a human is born and not another species? How does he inherit the traits of his parents? Who decides what the child will be like, what qualities and whose appearance he will inherit? How will hereditary diseases be reflected? These questions are answered by the science of genetics.
So what happens during conception? Inside the sperm, which carries the father's code, there is one strand-chain (DNA molecule), where each link is a gene. In addition, this chain is divided into 23 parts, each of which is twisted into a tight spiral, its name is a chromosome. The female egg also contains DNA with the mother's genes, broken down into 23 chromosomes. After these two chains are combined, all the information necessary to create a new organism will be collected: 46 chromosomes and about 35 thousand genes.
They (genes) are responsible for hair color, blood type, height, metabolism and other signs. Already at the first stage, the sex of the baby is known. This is encoded on the 23rd (sex) chromosome of the parents. This is what nature has ordered, but whether you have a girl or a boy depends only on your dad. The fact is that the mother's egg always contains only the female chromosome 23. It is commonly called the X chromosome. And the sperm can carry both the female (X) and the male - the Y-chromosome. Therefore, if an X-sperm is fused with an X-egg, then a pair XX will turn out, which means a girl will be born.
If the sperm was with a Y chromosome, then the XY pair will allow a boy to appear. That's all the wisdom, and folk omens, tables, diets, clinics promising the sex of the child on request give results close to the natural sex ratio, that is, about 50% to 50%.
We cannot influence the appearance of the child either. Nature itself will determine who he looks like. Although if the parents are very different in type, you can assume something. For example, blondes, blue-eyed, people with the first blood group, a negative Rh factor fall into the group of people with weak hereditary genes. But people with dark hair, curly, tall, right-handed have more chances that the offspring will look like them. For example, if mom is blonde and dad is a burning brunette, then the child will be born with dark hair. But, having matured and married a blonde girl, he can pass on his gene to his children, inherited from his mother. In this case, a blonde-haired baby will appear in a pair of blonde-brunette. We must not forget that some traits can only be inherited by boys or girls, manifest in adolescence, old age or in a certain external environment.
All this does not allow us to accurately guess the final result where nature will stop.