People feel very happy and distribute sweets when a male child is born. But when a female child comes, most people become unhappy and blame its mother for giving birth to a girl. It is a known fact that mother has nothing to do regarding the birth of a boy or girl because it is the father’s genes that determine this. Still, most people are confused in this area. A recent study by Newcastle University, UK involving thousands of families gave the details- whether they are likely to have sons or daughters. The work by Corry Gellatly, a research scientist at the university, has shown that men inherit a tendency to have more sons or more daughters from their parents. This means that a man with many brothers is more likely to have sons, while a man with many sisters is more likely to have daughters.
The research involved a study of 927 families containing information on 5,56,387 people from North America and Europe. According to the family tree study, Mr Gellatly said that whether you are likely to have a boy or a girl is inherited.
A gene consists of two parts, known as alleles, one inherited from each parent. In his paper, Mr Gellatly demonstrates that men carry two different types of allele, which results in 3 possible combinations in a gene that controls the ratio of X and Y sperm. Men with the first combination, known as (mm), produce more Y sperm and have more sons. The second, known as (mf), produce a roughly equal number of X and Y sperm and have an approximately equal number of sons and daughters. The third, known as (ff) produce more X sperm and have more daughters.
Hence, the man determines the sex of a baby depending on whether his sperm is carrying an X or Y chromosome. An X chromosome combines with the mother’s X chromosome to make a baby girl (XX) and a Y chromosome will combine with the mother’s to make a boy (XY).