NOVA Online | Cracking the Code of Life

Genome Facts

With the flurry of media attention surrounding the race to sequence the genome, it often seems as if the myriad genome facts and news items floating around could fill up a couple of telephone books. If you feel bombarded, imagine how the decoders feel: If written out, a human genetic code would fill the pages of 200 1,000-page New York City telephone directories. Though we can't compile all the facts here, this list of mind-boggling facts and figures will get you started. For more basic information about genes, visit the Glossary.

A rough draft of the human genome was completed in June 2000. Efforts are underway to complete a final draft of the human genome, expected sometime in 2003.
Since it began in 1990, the Human Genome Project is estimated to have cost $3,000,000,000.
The entire human genome requires three gigabytes of computer data storage space. (One million base pairs of sequence data equals one megabyte of storage space; the human genome has three billion base pairs.)
Every second, Human Genome Project computers decode 12,000 letters.
For the Human Genome Project, researchers collected blood (female) or sperm (male) samples from a large number of donors. Only a few samples were processed as DNA resources, and the source names remain confidential, so neither donors nor scientists know whose DNA is being sequenced.
The human genome sequence generated by the private genomics company Celera was based on DNA samples collected from five donors who identified themselves only by race and sex.
The vast majority of DNA in the human genome -- about 97 percent -- consists of non-genetic sequences with unknown function, sometimes called "junk DNA."
Human DNA is 98 percent identical to chimpanzee DNA.
The average amount of genetic difference between any two chimpanzees is four or five times more than the average difference between any two humans, which is 0.2 percent, or one in 500 letters. (This takes into account that human cells, unlike chimpanzee cells, have two copies of the genome.)
If two different people started reciting their individual genetic code at a rate of one letter per second, it would take almost eight and a half minutes before they reached a difference.
Humans have approximately 30,000 genes.
The roundworm has 19,098 genes.
The fruit fly has 13,602 genes.
Yeast has 6,034 genes.
The microbe responsible for tuberculosis has approximately 4,000 genes.
There are 100 trillion (100,000,000,000,000) cells in your body.
There are three billion (3,000,000,000) base pairs in the DNA code within each cell.
If unwound and tied together, the strands of DNA in one cell would stretch almost six feet but would be only 50 trillionths of an inch wide.
If all the DNA in your body was put end to end, it would reach to the sun and back over 600 times (100 trillion times six feet divided by 92 million miles).
It would take a person typing 60 words per minute, eight hours a day, around 50 years to type the human genome.
If all three billion letters in the human genome were stacked one millimeter apart, they would reach a height 7,000 times the height of the Empire State Building.

For more information about genes, visit the Glossary.

Sources: (1-5, 7, 15-21) National Human Genome Research Institute Web site; (2) NOVA "Cracking the Code"; (8-10, 13-14) New York Times; (11-12) Oak Ridge National Laboratory Web site; (6) Celera Genomics Web Site.

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Sequence for Yourself | Journey into DNA | Meet the Decoders
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