Related Words

Precursor: A substance used as a building block for another substance.

Somatic Cells: Any cell in the body except gametes and their precursors.

Advanced Research Project Agency (ARPA): The U.S. Department of Defense agency that, in conjunction with leading universities, created arpanet, the precursor of the Internet.

Anglo-Saxon: (1) Historically, the term refers to a group of Teutonic tribes who invaded England in the fifth and sixth centuries following the departure of Roman legions in 410 CE. These tribes, the Ang . . . View Full Definition

Somatic Cell: A cell that is not or will not become a gamete; the cells of the body.

Alchemy: The medieval and Renaissance precursor to modern chemistry, characterized by mystical philosophy and attempts to turn 'base' metals such as lead and tin into 'noble' metals such as gold and . . . View Full Definition

Ozone (O3): A nearly colorless gas and a form of oxygen (O2). It is composed of an oxygen molecule made up of three oxygen atoms instead of two.

Agricultural Act Of 1970: P.L. 91-524 (November 30, 1970) initiated a significant change in commodity support policy. This 3-year farm bill replaced some of the more restrictive and mandatory features of acreage allo . . . View Full Definition

Acid Deposition: Abnormally acidic (low ph) precipitation (or dry deposition) resulting from emissions of sulfur and nitrogen compounds that transform during chemical processes in the atmosphere. Acid deposi . . . View Full Definition

Clean Air Act: The primary federal law governing efforts to control air pollution. Federal legislation addressing air pollution was first adopted in 1955 (Air Pollution Control Act, P.L. 84-159) to provide . . . View Full Definition