what are three major differences between the chemical structures of rna and dna?
First of all, the nucleotides of DNA and RNA are different: in DNA, in fact, pentose sugar is deoxyribose, while in RNA it is ribose, which has one more oxygen atom. Moreover, in DNA the nitrogen bases are adenine, cytosine, guanine and thymine while in RNA instead of thymine there is the uracil base.