Question

DNA and RNA share a number of similarities, but they also differ in certain aspects of their structure.

Answer 1

Uracil is not found in DNA, only RNA, and replaces thymine in RNA 

Answer 2

The correct answer is uracil.

Uracil is a nitrogen base that is found in the RNA and not in the DNA, which has thymine. The three other nitrogen bases are the same ( Adenine, Guanine and Cytosine).

Besides the difference in the nitrogen bases, the two molecules also differ in the sugar that builds the structure ( DNA has desoxyribose and RNA has ribose) and the DNA is a two stranded helix, whereas the RNA is a single stranded molecule.