Part one of term paper
In one in every one thousand births, an extra chromosome results in the birth of a baby with Down's Syndrome; a genetic disorder resulting in mental retardation. In 1866, physician John Langdon Down, in Surrey England, identified a set of children with common features of mental retardation. Down was first to identify a similar link of sympt ...

Part two of term paper
... maps of afflicted patients by combining fluorescence hybridization, and Southern blot dosage analysis, therefore mapping out the chromosomal makeup of Down's patients. Their research revealed abnormalities on the twenty first pair of chromosomes. With the new research findings, Down's syndrome was traced to it's source, an error in cell development and the mutation of autosomal cells which results in three major types of Down's syndrome. Trisomy 21, involves the presence of extra genetic materi ...