Gene

In the early 20th century following the rediscovery of the important work of Gregor Mendel that provided the foundation for the future field of genetics, scientists developed the classical concept of the gene as the entity responsible for many human traits and diseases. It was soon learned that genes are located on the chromosomes and each person has two copies of a particular gene, one on each of the paired chromosomes that are inherited from one's parents, one of maternal origin and the other from the father. The alternate forms of a gene that result from the process of mutation are called alleles.

The 21st century likewise began with significant discoveries in the world of genetics. The Human Genome Project (HGP) begun in the mid-1980s by ...