DNA and RNA Bases. In DNA, there are four different bases: adenine (A) and guanine (G) are the larger purines. Cytosine (C) and thymine (T) are the smaller pyrimidines.
Gretna is the second-largest city and parish seat of Jefferson Parish, Louisiana, United States. Gretna is on the west bank of the Mississippi River, just east and across the river from uptown New Orleans. It is part of the New Orleans â Metairie â Kenner Metropolitan Statistical Area. The population was 17,736 at the 2010 census.
Gretna Green is a village in the south of Scotland famous for runaway weddings. It is in Dumfries and Galloway, near the mouth of the River Esk and was historically the first village in Scotland, following the old coaching route from London to Edinburgh. Gretna Green railway station serves both Gretna Green and Gretna.