Scientists have formally published a detailed analysis of the DNA sequence found on chromosome one - marking the completion of the Human Genome Project.
Chromosome one contains more than 1,000 new genes
Chromosome one is the largest "bundle" of genetic material found in cells, and comprises about 8% of our genome.
Researchers say defects on chromosome one are involved in more than 350 diseases, including Parkinson's and Alzheimer's; as well as some cancers.
The full details are in a landmark paper in the journal Nature.
The international Human Genome Project - often described as the "book of life" - was launched with the aim of finding and detailing the genes in our cells that drive all the body's biochemical reactions.
Scientists envisage using this information to diagnose illnesses and to develop new medical therapies.
A draft of the genome was published in 2001; and in 2003, a far more accurate sequence of the DNA code was completed, although there were still some gaps in it.
The detailed analysis of the 22 numbered chromosomes, plus the X and Y sex chromosomes, means the description of the gene content of the human genome has now achieved a "gold standard".
"This moment, the publication of the sequence from the last and largest human chromosome, completes the story of the Human Genome Project and marks the growing wave of biological and medical research founded on the human genome sequence," said Dr Simon Gregory, assistant professor from Duke University, who led the project while at the Sanger Institute in the UK.
THE DNA MOLECULE
The double-stranded DNA molecule is held together by four chemical components called bases
Adenine (A) bonds with thymine (T); cytosine(C) bonds with guanine (G)
Groupings of these "letters" form the "code of life"; there are about 2.9 billion base-pairs in the human genome wound into 24 distinct bundles, or chromosomes
Written in the DNA are about 20-25,000 genes which human cells use as starting templates to make proteins; these sophisticated molecules build and maintain our bodies
The sequencing of chromosome one took an international team of scientists 10 years to complete. They found that it contains 3,141 genes, more than 1,000 of which were completely new to science.
"The interpretation of what the genes are and how these gene products interact with one another will be the next volume that follows on from this initial volume of this human genome," Dr Gregory told the BBC News website.
The chromosome has already been linked to many diseases. It has been associated with cancers, high cholesterol, Parkinson's disease and Alzheimer's disease.
It is hoped that the sequence will help researchers find new diagnostics and treatments.
"Chromosome one contains fascinating stories of chromosome biology, of our evolution, and our health, and it's inspiring to have played a part in a programme that will have so much power to understand the essence of human biology," said Dr Gregory.
The sequence of chromosome one, along with all of the other sequences, has been made publicly available.