Which nitrogenous bases are present in RNA?

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

Answer: (B)

Verified step by step guidance

1. Recall that nucleic acids DNA and RNA are composed of nitrogenous bases paired with a sugar-phosphate backbone.
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 present in RNA are adenine (A), uracil (U), cytosine (C), and guanine (G).
5. Use this knowledge to select the correct answer choice that lists adenine, uracil, cytosine, and guanine as the bases in RNA.