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.
Ravenna is a city in Portage County, Ohio, United States. It was formed from portions of Ravenna Township in the Connecticut Western Reserve. The population was 11,771 at the 2000 Census and 11,724 in 2010. It is the county seat of Portage County. It is named for the city of Ravenna, Italy.