Question

A nitrogenous base is present in RNA but absent in DNA. Name it. Give examples in which it exists.

Answer 1

Hint: The DNA is the deoxyribose nucleic acid and the RNA is the ribo nucleic acid. These two substances are made up of proteins that contain the genetic materials that pass from the parent to the offspring to exhibit their own characters.

Complete answer:
The nucleotides form the building block of both DNA and RNA nucleic acid. Hence the DNA and the RNA consists of the sequence of the nucleotide. They are made up of the bases. In DNA, the four bases are found. They are adenine (A), guanine (G), cytosine(C) and the thymine (T).
Whereas the RNA is made up of the bases similar to that of the DNA but the thymine is replaced with the cytosine. Both the DNA and the RNA possess similar purine bases that are adenine and the guanine. But the pyrimidine bases of the DNA and the RNA differ, since the pyrimidine bases of the DNA are thymine and the cytosine but the pyrimidine bases of the RNA are uracil and the cytosine.

Thus the uracil base is present in RNA but not in DNA. The example for this RNA is UTP (Uridine triphosphate).

Note: DNA is the double stranded structure but the RNA is the single stranded structure. This structure is made up of the nucleotide which consists of the phosphate, sugar and the nitrogen bases. These are linked to form the chain of molecules that end up with the bases.