Which of the following bases is not associated with deoxyribonucleic acid (DNA)?

Uracil is not associated with deoxyribonucleic acid (DNA) because it is a characteristic component of ribonucleic acid (RNA). In DNA, the four bases are adenine, thymine, cytosine, and guanine. Uracil takes the place of thymine in RNA, pairing with adenine during the formation of RNA sequences. Thus, while adenine, thymine, and guanine are integral to the structure of DNA, uracil is exclusive to RNA. This distinction is crucial in molecular biology, particularly in understanding the roles and functions of DNA and RNA in genetic encoding and protein synthesis.