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.
Zip Code 68028 Description. Zip Code 68028 is located in the state of Nebraska in the Omaha metro area. Zip code 68028 is primarily located in Sarpy County. The official US Postal Service name for 68028 is GRETNA, Nebraska. Portions of zip code 68028 are contained within or border the city limits of Gretna, NE, . The area code for zip code 68028 is 402. 68028 can be classified socioeconically as a Middle Class class zipcode in comparison to other zipcodes in Nebraska.