The human body is made up of 23 pairs of chromosomes. Each chromosome contains loads of information in the form of genes which determine the hereditary characteristics of each individual. Each gene has two alleles, one containing genetic information from the father, the other from the mother. If the two alleles of an individual are identical the characteristic of that allele will be expressed. If, on the other hand, they are different, the dominant allele will impose itself on the recessive one, and the dominant allele will give its characteristic to the individual. Take for example eye color: if a child inherits one "brown" allele and one "blue" allele, he/she will have brown eyes because the brown allele is dominant and the blue allele is recessive.
Original article published by
. Translated by Jeff