Monday 26 August 2013

A child is a harbinger of joy in the family.When we look at the human race we find it is divided into two sexes-male and female.The questions that immediately arise in our minds are: Why don't all people belong to one sex?What is it that determines the sex of a child?A woman becomes capable of bearing a child after she starts menstruation .Between the 10th and the 18th days from on the onset of menstruation,the reproductive organs of a woman produce an egg called 'Ovum.During this period if a woman mates with a man,a sperm present in the semen of the man fertilises the egg.The combination of the ovum of the female and the sperm of the male results in the formation of the embryo in the women.
This Diagram shows the structure of Chromosomes
 The ovum of the female and the sperms of the male contain sex chromosomes.The ovum have only one type of chromosomes called X chromosomes.But the sperms have two types of sex chromosomes called X and Y chromosomes respectively.X chromosomes are slightly bigger than Y chromosomes in size.If during the process of conception, X chromosomes from the sperms fertilized the ovum, a girl is born.If, however, Y chromosome fertilizes the ovum, male child is conceived.Hence the combination of Y-X chromosomes leads to the conception of a male child.
The fusion of the sperms and ovum to formation of zygote.
  Sometimes in uneducated families women are blamed for bearing only daughters.But,as it is evident,females are not responsible for this.It is purely biological process and the birth of a male or female entirely depends upon the behaviour of the sex chromosomes of the male sperms. 

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