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 was born on a farm in Fairfax County, Virginia, on December 11, 1725. He led Virginia patriots during the American Revolution, and his concept of inalienable rights influenced Thomas Jeffersonâs Declaration of Independence.eorge Mason was an American patriot who participated in the American Revolution and the Constitutional Convention and who was influential in penning the Bill of Rights.