Our society always make woman responsible for the birth of a girl. Most of us want sons rather than daughters. They think that daughters are burden as they will have to spend huge money for their daughter’s marriage. Another motive to have son is to continue their generation. But they don’t know that the birth of a girl depends on man’s chromosome.
Man has two types of chromosome called X and Y and woman has XX chromosome. When an X chromosome of father merges with X chromosome of mother then a baby girl (XX) is born. And if a Y chromosome of father comes together with an X chromosome of mother, a boy (XY) takes birth. So it is completely depends on father’s chromosome.
There is an university called Newcastle in England where thousands of families are working with expected parents to help them knowing whether they will give birth a boy or a girl.
Corry Gellatly, a research scientist, has found in a study that men have inherited properties to give birth more sons or more daughters. According to research, you may have more sons if you have many brothers. On the other hand, if you have more sisters rather than brothers, then the possibility of having daughters are higher.
The research team has studied 927 family trees that provided the data about 556,387 people. All of them are the resident of North America.
"The family tree study showed that whether you’re likely to have a boy or a girl is inherited. We now know that men are more likely to have sons if they have more brothers but are more likely to have daughters if they have more sisters. However, in women, you just can’t predict it," Mr Gellatly explains.
Till now scientists couldn’t be able to discover one property that is the amount of X chromosome and Y chromosome in the sperm of a man. If the number of men with more X chromosome is higher than the number of men with Y chromosome, then the possibility of the birth of daughters is higher than the birth of sons and vice-versa.
Source: https://www.sciencedaily.com/releases/2008/12/081211121835.htm