Which of the following nitrogenous bases is found in both DNA and RNA?

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

Answer: (D)

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 bases are common to both molecules.
4. Note that Thymine is found only in DNA, while Uracil is found only in RNA.
5. Conclude that the bases found in both DNA and RNA include Adenine, Cytosine, and Guanine.