How is the sex of the child determined in human beings?
Sex of the child depends on the presence of chromosomes ‘X and ‘Y’. Chromosome ‘Y’ is dominant over the chromosome ‘X’. When both chromosomes X and Y are present, the sex of the child is male; while if both the chromosomes are X then the sex of the child is female.
There are 50:50 chances for a male or female child.
Female produces only one type of chromosome that is X. So, Sex of the child does not depend on the mother. If the germ cell of father carries the x chromosome, the child is a girl; and if it carries y chromosome, the child is a boy.
See also: A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?