Why there is inequality of sexes in human population?

Explanation

Women plays a very important role in the continuity of the family and human species. She nourishes the foetus in her womb for nine months and after birth she nourishes the infant untill the child learns to feed herself/himself. Hence biologically woman is superior to man. However, women are a victim of social injustice, and are treated inferior to man. But an educated person who has understood the scientific basis of sex determination, should be rational and objective and free from prejudice in matters pertaining to the equality of sex. In fact man should feel obliged to woman because she plays a significant role in the continuity of the family and human race.
Human female produces similar eggs (ova), each with X chromosomes. However, human male roduces two types of sperms, 50% sperms have X chromosomes and 50% sperms possesss Y hromosomes. The sex of the newly born child is solely determined by the type of sperm that fertilises the egg (ovum). If the egg is fertilised by an X-bearing sperm a girl is produced. If the egg ovum) is fertilised by a Y-bearing sperm, a boy is produced. Which type of sperm fuses with the egg is purely a chance. Thus it is the father who is biologically responsible for the sex of the child. unfortunately, it is the mother who is always blamed for giving birth to female child.