Answer:it is a characteristic of DNA
Step-by-step explanation:
Deoxyribonucleic acid(DNA) is made 5 carbon deoxyribose sugar, phosphate group,Nitrogenous base which include purine and pyrimidine. Purine base compose of Adenine and guanine while pyrimidine base compose of Cytosine and thymine.
In Ribonucleic acid (RNA) we have 5 carbon ribose sugar, phosphate group and nitrogenous bases which are purine and pyrimidine. Purine consist of Adenine and guanine while pyrimidine compose of Cytosine and Uracil where thymine in DNA is replaced by Uracil in RNA. This makes Thymine a components of DNA not RNA.