Which one is wrongly matched ?

Options

A. Guanine, adenine-Purines
B. Thymine, uracil-Pyrimidines
C. Uracil, cytosine-Pyrimidines
D. Adenine, thymine- Purines.

Answer

To determine which option is wrongly matched in the context of nitrogenous bases, we need to analyze the classifications of the bases and their pairings. Here’s a step-by-step solution:

### Step 1: Understand the Classification of Nitrogenous Bases
Nitrogenous bases are classified into two categories:
- **Purines**: These have a double-ring structure. The purines include:
- Adenine (A)
- Guanine (G)

- **Pyrimidines**: These have a single-ring structure. The pyrimidines include:
- Thymine (T)
- Cytosine (C)
- Uracil (U) (found in RNA instead of thymine)

### Step 2: Analyze the Options
Now, let's look at the options provided in the question:
1. **Guanine and Adenine** - Both are purines. This is correctly matched.
2. **Thymine and Uracil** - Both are pyrimidines. This is correctly matched.
3. **Uracil and Cytosine** - Both are pyrimidines. This is correctly matched.
4. **Adenine and Thymine** - Adenine is a purine, while thymine is a pyrimidine. This is incorrectly matched.

### Step 3: Identify the Wrong Match
From the analysis:
- The only incorrect match is **Adenine and Thymine**. While adenine is a purine, thymine is a pyrimidine. Therefore, this pair does not belong to the same category.

### Conclusion
The wrongly matched pair is **Option D: Adenine and Thymine**.

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