Structure Of Dna And Rna

There are purines and pyrimidines that are of concern to us. Cytosine is termed in both RNA and DNA. Uracil is found only in RNA. Thymine is normally found in DNA. Therefore, in the given options only guanine is purine base. So it is present in RNA.

Ribose and deoxyribose are carbon sugars which are found in RNA and DNA. They have a furanose structure that is a membered ring system with carbon atoms and one oxygen atom.

Step 1: Genetic code is triplet code.

Step 1: In DNA: %A = %T, %G = %C
Step 2: Given A = 30%, so T = 30%.
Step 3: Remaining: 100 - 60 = 40% = G + C ⟹ C = 20%

Each codon consists of three nucleotides that code for one amino acid.