Which of the following is only present in RNA

Options

A. 5-methyl uracil
B. 2,4 dioxy uridylate
C. 6-amino purine
D. 2 -amino 6-oxy purine

Answer

To solve the question "Which of the following is only present in RNA?", we need to analyze the options provided and identify which one is unique to RNA.

### Step-by-Step Solution:

1. **Understand the Components of RNA and DNA**:
- RNA (Ribonucleic Acid) and DNA (Deoxyribonucleic Acid) are both nucleic acids that consist of nucleotides. Each nucleotide contains a sugar, a phosphate group, and a nitrogenous base.

2. **Identify the Nitrogenous Bases**:
- The nitrogenous bases found in RNA are adenine (A), guanine (G), cytosine (C), and uracil (U).
- The nitrogenous bases found in DNA are adenine (A), guanine (G), cytosine (C), and thymine (T).

3. **Examine the Options**:
- **Option A: 5-methyl uracil** - This is another name for thymine, which is found in DNA, not RNA.
- **Option B: 2,4-dioxyuridate** - This is a modified form of uracil, which is indeed present only in RNA.
- **Option C: 6-Aminopurine** - This is a form of adenine, which is found in both RNA and DNA.
- **Option D: 2-Amino 6-Oxypurine** - This is also a form of adenine, found in both RNA and DNA.

4. **Determine the Correct Answer**:
- From the analysis, the only base that is unique to RNA is **uracil** (which is part of the structure of 2,4-dioxyuridate). Therefore, the correct answer is **Option B: 2,4-dioxyuridate**.

### Final Answer:
The correct answer is **Option B: 2,4-dioxyuridate**, which is only present in RNA.