The four nitrogenous bases that make up the DNA structure are divided into two groups, called purines and pyrimidines. Adenine and guanine are purines, and chemically are double-ringed structures - a five cornered ring and a six cornered ring. They are much larger than pyrimidines.
James Mason (I) (1909â1984) James Mason was a great English actor of British and American films. He was born in Yorkshire, and attended Marlborough and Cambridge, where he discovered acting on a lark, and abandoned a planned career as an architect. Following work in stock companies, he joined the Old Vic under the guidance of Sir Tyrone Guthrie and of Alexander Korda, who ...
George Mason University (also Mason), located in Fairfax, Virginia, United States, is the largest public research university in the Commonwealth of Virginia. The university was founded as a branch of the University of Virginia in 1957 and became an independent institution in 1972. Today, Mason is recognized for its strong programs in economics, law, creative writing, computer science, and business.