The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

metric system

A decimal system of weights and measures, adopted first in France but now widespread over the world, universally used in science, mandatory for use for all purposes in a large number of countries, and permitted for use in most (as in the U.S.). The basic units are the meter (39.37 inches) for length and the gram (15,432 grains) for mass or weight. A derived unit is the liter (0.908 U.S. dry quart, or 1.0567 U.S. liquid quart) for capacity, being the volume of 1000 grams of water under specified conditions. Names for units larger and smaller than these are formed from the above names by the use of the following prefixes: kilo, 1000; hecto, 100; deca, 10; deci, 0.1; centi, 0.01; milli, 0.001. To these are often added: tera, one trillion, giga, one billion; mega, one million. With the addition of basic physical units, it is now officially known in English as the International System of Units.