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 determine which of the following is only present in RNA, we will analyze each option provided:

1. **Option A: Biomethyl Uracil**
- Biomethyl uracil is actually thymine. Thymine is formed when a methyl group is added to uracil at the 5th position. Since thymine is found in DNA and not RNA, this option is not correct.

2. **Option B: 2,4-Dioxyridylate**
- This compound relates to uracil, which is a pyrimidine base found in RNA. However, the term "2,4-dioxyridylate" is not a standard name for uracil, and uracil itself is present in RNA, but this option does not specify uracil directly.

3. **Option C: 6-Aminopurine**
- 6-Aminopurine is another name for adenine, which is one of the nucleobases found in both DNA and RNA. Therefore, this option is also not correct.

4. **Option D: 2-Amino-6-Oxypurine**
- This compound is known as guanine, which is also found in both DNA and RNA. Thus, this option is incorrect as well.

After analyzing all the options, we find that the only nucleobase that is unique to RNA is **uracil**. In RNA, uracil replaces thymine, which is found in DNA.

**Final Answer: Uracil**