What determines whether a baby is a boy or a girl? It lies largely in the DNA. And who decides in principle to gender, father or mother? And what if something goes wrong with the DNA?
Chromosome 23
Or a man a man or a woman, has largely to do with DNA. My article provides more information about DNA DNA itself, here I will discuss the differences between men and women in the DNA. Each human cell has a nucleus where DNA. This DNA is all the information for each cell in the body is important. Thus there is in the DNA in the cells of the liver is also information for cells in the heart, and vice versa. The difference is that the information is in the heart or liver, but not used. The binders remain in the closet so to speak.
The nucleus is the DNA in bite-sized chunks, the chromosomes. And each strand then even two instances where I can get up the same. There are 23 pairs of chromosomes, 46 chromosomes. Only the 23rd pair is different. This is the sex chromosome, and two times the same X chromosome, they belong to a woman. If it is once again one X and one Y, then the owner is a man. Why?
For the production of sperm and eggs are the chromosome pairs exploded. There are no 23 pairs, but 23 separate chromosomes. When the woman is always a 23rd chromosome X. The 23rd chromosome pair comprises two X's. In sperm, the 23rd chromosome or an X or a Y. The 23rd pair of chromosomes of a man is XY, which is split, one sperm gets the X and the other gets Y. If the X from the man with the egg of the woman melts, a daughter was born, and the Y of the man with the egg melts, a son is born.
Hormonal influences
Yet there are women with the 23rd pair of chromosomes X and Y exists. Or men with two X's. In that case there are hormonal influences that prevail. There are so many girl babies are male hormones that they produce the sexual characteristics of a boy. The 23rd pair of chromosomes is not always say everything, and this is especially for those affected them very annoying.
Errors in the splitting of the chromosomes
Sometimes something goes wrong in sharing the chromosomes. The most common abnormality is not part of chromosome 21 in one of the two parents. This gives the child a total of three chromosomes with the same number. This produces Down's syndrome. In most other sub-faults fetuses can not grow, but some error when the sex chromosomes that usually succeeds. It will allow children born with XXY (Klinefelter's syndrome), XYY, X, XXX (super women) and even XXXXY.
Because there are two chromosomes of all, all genetic traits present in duplicate in the cell. A piece of information on a chromosome for a particular trait is called a gene. There are genes for eye color, height, hair color and so on. Yet most people only one eye color, length is also quite solid and the natural color of hair, while those qualities have two genes - one from the mother's and one from the father is. But one of the two descriptions for the properties is dominant. The other trait is recessive, submissive. An example: brown eyes are dominant over blue. As a child of his father's gene "brown eyes" message, and his mother's gene 'blue eyes', the child will have brown eyes, but also the "blue ogen' gene. It is not just expressed. Only if both parents' genes get ogen' blue, the child has blue eyes. But beware: if the father has brown eyes, he can still be a child "blue gene ogen' give. He may indeed a "blue ogen' gene and a brown eye gene and one of these two genes gives to his child. The mother is the child a "blue ogen' gene indicate if they have brown eyes. For example, a child who has parents with brown eyes, but blue eyes. Well it's not as simple as it appears here, and it's not quite as straight-to-earth to. Sometimes the child has very different properties than their parents. Epigenetics may play a role.
Epigenetics
Epigenetics means that certain changes during the life of the DNA that made up the parent does not return, but the child did. But this is not all known. In any case, a father need not always be the milkman to see if a child has particular characteristics that neither the mother nor to prevent him ...