Which of the following base is found only in RNA and not in DNA?

Options

A. Thymine
B. Guanine
C. Uracil
D. Adenine

Explanation

To determine which base is found only in RNA and not in DNA, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Nitrogenous Bases**:
- The five nitrogenous bases are adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U).

2. **Classify the Bases**:
- Nitrogenous bases can be classified into two categories: purines and pyrimidines.
- **Purines**: Adenine (A) and Guanine (G)
- **Pyrimidines**: Cytosine (C), Thymine (T), and Uracil (U)

3. **Identify Bases in DNA**:
- DNA (Deoxyribonucleic Acid) contains the following nitrogenous bases:
- Adenine (A)
- Guanine (G)
- Cytosine (C)
- Thymine (T)

4. **Identify Bases in RNA**:
- RNA (Ribonucleic Acid) contains the following nitrogenous bases:
- Adenine (A)
- Guanine (G)
- Cytosine (C)
- Uracil (U)

5. **Compare the Bases**:
- The key difference between the bases in RNA and DNA is that RNA contains uracil (U) instead of thymine (T), which is present in DNA.

6. **Conclusion**:
- The base that is found only in RNA and not in DNA is **Uracil (U)**.

### Final Answer:
The base found only in RNA and not in DNA is **Uracil (U)**.

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