Uracil is a ...................... base, which is present in............... .

Explanation

### Step-by-Step Solution:

1. **Identify the Type of Molecule**:
- Uracil is a type of nitrogenous base. Nitrogenous bases are the building blocks of nucleic acids.

2. **Determine the Nucleic Acid**:
- Uracil is specifically found in RNA (ribonucleic acid). It is one of the four nitrogenous bases that make up RNA, the others being adenine, guanine, and cytosine.

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