A nitrogenous base is present in RNA but absent in DNA . Identify it .

Explanation

To solve the question, "A nitrogenous base is present in RNA but absent in DNA. Identify it," we can follow these steps:

### Step-by-Step Solution:

1. **Understand Nucleotides**: Nucleotides are the building blocks of nucleic acids, which include DNA and RNA. Each nucleotide consists of three components: a phosphate group, a pentose sugar, and a nitrogenous base.

2. **Identify the Components**:
- The phosphate group is common in both DNA and RNA.
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