Which element is not found in nitrogenous base :-

Options

A. Nitrogen
B. Hydrogen
C. Carbon
D. Phosphorus

Answer

To determine which element is not found in nitrogenous bases, follow these steps:

### Step-by-Step Solution:

1. **Understand the Composition of Nitrogenous Bases**:
- Nitrogenous bases are the building blocks of nucleic acids (DNA and RNA).
- They are primarily composed of three elements: nitrogen (N), hydrogen (H), and carbon (C).

2. **Identify the Types of Nitrogenous Bases**:
- Nitrogenous bases are categorized into two types: purines and pyrimidines.
- Purines include adenine (A) and guanine (G).
- Pyrimidines include cytosine (C), thymine (T), and uracil (U).

3. **Analyze the Given Options**:
- The options provided are: nitrogen, hydrogen, carbon, and phosphorus.
- From the understanding of nitrogenous bases, we know that nitrogen, hydrogen, and carbon are all components of these bases.

4. **Determine the Element Not Found in Nitrogenous Bases**:
- Phosphorus (P) is not a component of nitrogenous bases. Instead, phosphorus is found in the backbone of nucleic acids, specifically in the phosphate group that links the sugar molecules.

5. **Conclude the Answer**:
- Therefore, the element that is not found in nitrogenous bases is **phosphorus**.

### Final Answer:
Phosphorus is the element not found in nitrogenous bases.

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