Question

Name the purine bases and pyrimidine bases present in RNA and DNA

Answer 1

Hint: The main components of the DNA and RNA are made up of sugar and phosphate chain which act as the backbone of the RNA and DNA. These sugar chains contain nitrogenous bases made up of nitrogen rings and carbon. Number of rings decides whether it is purine or pyrimidine.

Complete step by step answer:
Purines are larger bases and contain two rings and pyrimidine is comparatively smaller, and contains one ring. DNA has two strands, one called forward strand and the other is called backward strand. For holding these two strands together, the purine bases of one strand make hydrogen bonding with the pyrimidine bases of the other strand. This function of the DNA molecule is called base pairing. The ratio of purine and pyrimidine is always constant due to the property of complementary pairing which states that pyrimidine will always bind to purine. Purine are of two types: Adenine and Guanine, and both are present in RNA and DNA both. Pyrimidines are of three types but only one that is Cytosine is present in both DNA and RNA. Among the rest two, Uracil is present only in RNA, and Thymine is present only in DNA. Adenine and Guanine have two hydrogen bonds between them and guanine and cytosine have three hydrogen bonds between them. Two rings of the purines (Adenine and Guanine) are made up of nine elements with four nitrogen atoms and the one ring of the pyrimidines is made up of only six elements with two nitrogen atoms.
Hence, purine bases which are present in:
DNA: Adenine and Guanine,
RNA: Adenine and Guanine
and pyrimidine base which are present in:
DNA: Cytosine and Thymine,
RNA: Cytosine and Uracil

Note:
One way to keep in mind which base will make bonding with which base, observe the shape of the letters. A and T are made up of straight lines only, so, they will always be in one group, and G and C are made up of curve lines, so, they will be grouped together.