Adenine, Guanine, Cytosine and Thymine - A and G are Purines, C and T are Pyrimidines. Double bond between A and T, triple between C and G; And there is 4 not 3 bases found in DNA. And not nitrogen but nitrogenous bases x
DNA is a polymer containing monomer units called nucleotides. The polymer DNA is known as polynucleotide. Each of the monomers that makes up DNA, which are known as nucleotides, consist of a five-carbon sugar called deoxyribose, a nitrogen-containing base which is attached to the sugar and a phosphate group. DNA is made up of four different types of nucleotides. These differ from each other only in the nitrogenous bases.
The four nucleotides have the abbreviations A, G, C and T, which are their initials. A is for for adenine, G is for guanine, C stands for cytosine and T stands for thymine. There are two types of nitrogenous bases called purine bases and pyrimidine bases. Purine bases are the larger of the two types of nitrogenous bases found in DNA. Adenine (A) and guanine (G) are purine bases. Purine bases have nine ring atoms numbered from one to nine, which lie in the same plane. Of the nine ring atoms, five are carbon atoms and four are nitrogen atoms. Cytosine (C) and thymine (T) are pyrimidine bases. Pyrimidine bases have six ring atoms numbered from one to six, which lie in the same plane. Of the six ring atoms, four are carbon atoms and two are nitrogen atoms.
Which part of a DNA molecules carries the genetic instructions that are unique for each individual; the sugar-phosphate backbone or the nitrogen-containing bases