Nucleotide constituents/nitrogen bases of RNA are

Options

A. AGCU
B. TCXU
C. AGCT
D. CTAU.

Answer

To answer the question regarding the nucleotide constituents or nitrogen bases of RNA, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Nucleotides**:
- Nucleotides are the building blocks of nucleic acids like DNA and RNA. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.

2. **Identifying Nitrogen Bases**:
- Nitrogenous bases are categorized into two types: purines and pyrimidines.
- **Purines**: These are larger, double-ring structures. The purines found in both DNA and RNA are adenine (A) and guanine (G).
- **Pyrimidines**: These are smaller, single-ring structures. In RNA, the pyrimidines are cytosine (C) and uracil (U).

3. **Listing RNA Nitrogen Bases**:
- From the above information, the nitrogen bases present in RNA are:
- Adenine (A)
- Guanine (G)
- Cytosine (C)
- Uracil (U)

4. **Excluding DNA Bases**:
- It is important to note that thymine (T), which is present in DNA, is not found in RNA. Instead, uracil (U) replaces thymine in RNA.

5. **Final Answer**:
- Therefore, the nitrogen bases of RNA are A, G, C, and U.

### Conclusion:
The nucleotide constituents or nitrogen bases of RNA are adenine (A), guanine (G), cytosine (C), and uracil (U).

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