Which nitrogenous bases are found in RNA?

• A. Adenine, cytosine, guanine, and inosine
• B. Adenine, uracil, cytosine, and guanine
• C. Adenine, uracil, cytosine, and thymine
• D. Adenine, thymine, cytosine, and guanine

Answer: (B)

Verified step by step guidance

1. Recall that nucleic acids DNA and RNA are composed of nitrogenous bases paired with sugar and phosphate groups.
2. Identify the four nitrogenous bases found in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G).
3. Understand that RNA differs from DNA in one key base: RNA contains uracil (U) instead of thymine (T).
4. Therefore, the nitrogenous bases in RNA are adenine (A), uracil (U), cytosine (C), and guanine (G).
5. Confirm that inosine is not a standard base in RNA, and thymine is replaced by uracil in RNA, so the correct set is adenine, uracil, cytosine, and guanine.