Which of the following bases is NOT found in DNA?

Uracil is the correct answer because it is a nitrogenous base that is found in RNA, not DNA. In DNA, the bases present are adenine, thymine, cytosine, and guanine. In contrast, RNA contains adenine, uracil, cytosine, and guanine. The presence of thymine in DNA is necessary for forming complementary base pairs with adenine, while uracil serves a similar purpose in RNA, pairing with adenine during the process of transcription. Understanding the specific bases in each nucleic acid type is crucial for grasping the fundamentals of genetic information storage and transfer.