Purine and pyrimidine nitrogen bases respectively are
A,T and G, C,U
A, C, T and G, U
A, G and C, T, U
A, G, T and C, U
The correct option is C A, G and C, T, U There are two kinds of nitrogen-containing bases: purines and pyrimidines. Purines consist of a six-membered and a five-membered nitrogen-containing ring, fused together. Pyridmidines have only a six-membered nitrogen-containing ring. There are 2 purines and 3 pyrimidines.
Purines: Adenine (A) = 6-amino purine and Guanine (G) = 2-amino-6-oxy purine. Adenine and guanine are found in both DNA and RNA.
Pyrimidines: Uracil (U) = 2,4-dioxy pyrimidine; Thymine (T) = 2,4-dioxy-5-methyl pyrimidine; Cytosine (C) = 2-oxy-4-amino pyrimidine. Cytosine is found in both DNA and RNA. Uracil is found only in RNA. Thymine is normally found in DNA.