Length of a Human DNA Molecule

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Bibliographic Entry	Result (w/surrounding text)	Standardized Result
Mitchel, Campbell Reece. Biology Concept and Connections. California, 1997.	"At actual size, a human cell's DNA totals about 3 meters in length."	3.0 m
McGraw Hill Encyclopedia of Science and Technology. New York: McGraw Hill, 1997.	"If stretched out, would form very thin thread, about 6 feet (2 meters) long."	2.0 m
Matthews, Harry R. DNA Structure Prerequisite Information. 1997.	"The length is (length of 1 bp)(number of bp per cell) which is (0.34 nm)(6 × 10⁹)"	2.0 m
Leltninger, Albert L. Biochemistry. New York: Worth, 1975.	"Chromosome 13 contains a DNA molecule about 3.2 cm long."	1.5 m
"Cell." The World Book Encyclopedia. Chicago: Field Enterprises, 1996.	"On the average, a single human chromosome consists of DNA molecule that is about 2 inches long."	2.3 m

The chromosomes in the nucleus of a cell contain all the information a cell needs to carry on its life processes. They are made up of a complex chemical (a nucleic acid) called deoxyribonucleic acid, or DNA for short. Scientist's decoding of the chemical structure of DNA has led to a simple conceptual understanding of genetic processes. DNA is the hereditary material of all cells. It is a double-stranded helical macromolecule consisting of nucleotide monomers with deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T). In the chromosomes of a cell, DNA occurs as fine, spirally coiled threads that in turn coils around another, like a twisted ladder.

The DNA molecule is threaded so fine that it is only possible to see it under high powerful electron microscopes. To get a sense of exactly how long an uncoiled DNA molecule is compared to a typical cell, a cell is magnified 1000 times. At this scale, the total length of all the DNA in the cell's nucleus would be 3 km -- the equivalent distance of the Lincoln Memorial to the capital in Washington, DC.

The human genome comprises the information contained in one set of human chromosomes which themselves contain about 3 billion base pairs (bp) of DNA in 46 chromosomes (22 autosome pairs + 2 sex chromosomes). The total length of DNA present in one adult human is calculated by the multiplication of

(length of 1 bp)(number of bp per cell)(number of cells in the body)
(0.34 × 10⁻⁹ m)(6 × 10⁹)(10¹³)
2.0 × 10¹³ meters

That is the equivalent of nearly 70 trips from the earth to the sun and back.

2.0 × 10¹³ meters = 133.691627 astronomical units
133.691627/2 = 66.8458135 round trips to the sun

On the average, a single human chromosome consists of DNA Molecule that is almost 5 centimeters.

Steven Chen -- 1998

Bibliographic Entry	Result (w/surrounding text)	Standardized Result
WNET-DT 13.1, 5:00 PM 10 May 2006.	"Unravel your DNA and it would stretch from here to the moon"	3.85 × 10⁸ m

Editor's Supplement -- 2006

External links to this page:

BioINFORMatic: DNA Packaging. Casey Sears. YouTube (2009).
US Patent 7,234,414 Mastitis detection. Rodney Wayne Claycomb & David Simon Whyte (2007).
US Patent Application US12/377,404 Method of electrically detecting a biological analyte molecule. Zhiqiang Gao, Yi Fan, Xiantong Chen, and Jinming Kong (2007).
US Patent Application US12/680,290 Method of electrically detecting a nucleic acid molecule. Jinming Kong, Yi Fan, and Xiantong Chen (2007).
On the length, weight and GC content of the human genome. Allison Piovesan, Maria Chiara Pelleri, Francesca Antonaros, Pierluigi Strippoli, Maria Caracausi, and Lorenza Vitale. BMC Research Notes. Vol. 12 No. 106 (2019).
DNA. CreationDesign.org (n.d.).
Privacy and Progress in Whole Genome Sequencing. Presidential Commission for the Study of Bioethical Issues. Washington, DC (2012).
Zeno's Paradox of Immortality. S. Jay Olshansky and Bruce A. Carnes. Geriatrics and Gerontology. Vol. 59 No. 1 (2012): 85–92.