DNA is fundamental to the biology of all life on Earth, but how many of us actually know what it is or what it's made of?

Adenine and guanine, the two most common purines in DNA and RNA, share this core structure, which is crucial for forming the base pairs in nucleic acids. (Image: Wikimedia Commons, Public Domain) ...

Rather, DNA was first identified in the late 1860s ... In other words, the total amount of purines (A + G) and the total amount of pyrimidines (C + T) are usually nearly equal.

DNA is the molecular basis of heredity ... Adenine and guanine are double-ring molecules called purines, but cytosine, thymine and uracil are all pyrimidines: single rings. To maintain its ...

Chemical structure of guanine, showing its double-ring purine structure and the functional groups involved ... This strong base pairing is crucial for the stability of the DNA double helix and the ...