The DNA double helix is held together by hydrogen bonds and the nucleotide bases Adenine, Guanine, Cytosine, or Thymine. Check out the source I provided. There's a great diagram of the double helix.Source(s): http://www.ba-education.demon.co.uk/for/...eport Abuse. Hydrogen bonds hold the two helices together to form a double helix. I also remember somethign called base stacking, which if i recall was hydrogen bonding of the same strand, which promoted the helical nature and enforced rigidity of the structure.
Norfolk, Nebraska. Norfolk (/ËnÉÉrfÉÉrk/ or /ËnÉÉrfoÊk/) is a city in Madison County, Nebraska, United States, 113 miles northwest of Omaha and 83 miles west of Sioux City at the intersection of U.S. Routes 81 and 275. The population was 24,210 at the 2010 census,[5] making it the ninth-largest city in Nebraska.
Madison County is a county located in the U.S. state of Nebraska. As of the 2010 census, the population was 34,876. Its county seat is Madison. Madison County was named for James Madison, 4th President of the United States. Madison County is part of the Norfolk, NE Micropolitan Statistical Area. In the Nebraska license plate system, Madison County is represented by the prefix 7 (the county had the seventh-largest number of vehicles registered in the state when the license plate system was established in 1922).