Which of the following is not present in nucleic acids

Options

A. Uracil
B. 2- aminopyridine
C. Thymine
D. Adenine

Answer

To determine which of the following is not present in nucleic acids, we need to analyze the options provided: uracil, 2-amino pyridine, thymine, and adenine.

### Step-by-Step Solution:

1. **Identify the Components of Nucleic Acids**: Nucleic acids, such as DNA and RNA, are made up of nucleotides. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.

2. **List the Nitrogenous Bases**: The nitrogenous bases found in nucleic acids include:
- **Adenine (A)**
- **Thymine (T)** (only in DNA)
- **Uracil (U)** (only in RNA)
- **Cytosine (C)**
- **Guanine (G)**

3. **Analyze the Options**:
- **Uracil**: Present in RNA.
- **Thymine**: Present in DNA.
- **Adenine**: Present in both DNA and RNA.
- **2-amino pyridine**: This is not a nitrogenous base found in nucleic acids.

4. **Conclusion**: The option that is not present in nucleic acids is **2-amino pyridine**.

### Final Answer:
**2-amino pyridine** is not present in nucleic acids.

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