Which nitrogenous base is found in DNA but not in RNA?

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

Answer: (B)

Verified step by step guidance

1. Recall the four nitrogenous bases found in DNA: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
2. Recall the four nitrogenous bases found in RNA: Adenine (A), Uracil (U), Cytosine (C), and Guanine (G).
3. Compare the bases in DNA and RNA to identify which base is unique to DNA and absent in RNA.
4. Note that Thymine (T) is present in DNA but replaced by Uracil (U) in RNA.
5. Conclude that the nitrogenous base found in DNA but not in RNA is Thymine.