Question

Which of the following nitrogen base is not found in DNA?

• A. Thymine
• B. Cytosine
• C. Guanine
• D. Uracil

Answer 1

The correct option is D Uracil

DNA is a polymer of deoxyribonucleotides. The deoxyribonucleotides are made up of phosphoric acid and deoxyribonucleosides. The deoxyribonucleosides are made up of deoxyribose sugars and nitrogenous bases. The nitrogenous bases present in DNA are purine (adenine or guanine) and pyrimidine (cytosine or thymine). Uracil is absent from DNA. Uracil is present as pyrimidine base in ribonucleotides which are components of RNA.
So, the correct answer is option D.