Changes

'''DNA''' is an organic [[molecule]] shaped like a ladder that is continuously twisted (see [[double helix]]). Its chemical name is

'''Deoxyribonucleic acid''' (DNA) is an [[organic compound|organic]] [[chemical compound]] made up of [[molecule]]s shaped like a [[double helix]], a continuously twisted ladder.

deoxyribonucleic acid.  

It carries the [[genetic]] coding for the [[protein]]s that form the bodies of living [[organism]]s. All living creatures contain DNA, and the DNA of two (sexually reproducing) creatures' offspring is a mix of its parents' DNA.

DNA carries the [[gene|genet]]ic coding for the [[protein]]s that form the bodies of living [[organism]]s. All organisms contain DNA, and the DNA of a sexually reproducing organism offspring is a mix of its parents' DNA.

==History==

==History==

In the late 19th century [[Friedrich Miescher]], a Swiss [[biochemist]], discovered several different proteins and an unusual [[acid]] in the [[nucleus]] of cells. The acid was named deoxyribonucleic acid, or DNA. In 1944 two American [[biologist]]s, [[Alfred Hershey]] and [[Martha Chase]] used experiments with [[bacteria]] and [[bacteriophages]] to show that DNA passed [[gene]]s from one generation to the next.  

In the late 19th century [[Friedrich Miescher]], a Swiss [[biochemist]], discovered several different proteins and an unusual [[acid]] in the [[nucleus]] of cells. The acid was named deoxyribonucleic acid, or DNA. In 1944 two American [[biologist]]s, [[Alfred Hershey]] and [[Martha Chase]] used experiments with [[bacteria]] and [[bacteriophages]] to show that DNA passed [[gene]]s from one generation to the next.