Which of the following base is not present in DNA ?

Options

A. Thymine
B. Quinoline
C. Adenine
D. Cytosine

Explanation

To determine which base is not present in DNA, we can follow these steps:

### Step 1: Identify the Bases Present in DNA
DNA (deoxyribonucleic acid) contains four nitrogenous bases. These are:
1. Adenine (A)
2. Thymine (T)
3. Cytosine (C)
4. Guanine (G)

### Step 2: List the Options Given in the Question
Assuming the options provided in the question are:
- A) Adenine
- B) Thymine
- C) Cytosine
- D) Uracil

### Step 3: Compare Each Option with the Bases in DNA
- **Adenine (A)**: Present in DNA.
- **Thymine (T)**: Present in DNA.
- **Cytosine (C)**: Present in DNA.
- **Uracil (U)**: Not present in DNA (Uracil is found in RNA).

### Step 4: Identify the Base Not Present in DNA
From the comparison, we can conclude that Uracil (U) is the base that is not present in DNA.

### Final Answer
The base that is not present in DNA is **Uracil (U)**.

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