The adenine base always pairs with the following in RNA

Options

A. thymine
B. guanine
C. cytosine
D. uracil

Answer

To solve the question about which base adenine pairs with in RNA, follow these steps:

### Step-by-Step Solution:

1. **Identify the Components of RNA**:
- RNA (ribonucleic acid) is composed of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and uracil (U).

2. **Understand Base Pairing Rules**:
- In nucleic acids, bases pair according to specific rules. In DNA, adenine pairs with thymine (T), while in RNA, adenine pairs with uracil.

3. **Determine the Pairing for Adenine in RNA**:
- Since RNA does not contain thymine, adenine must pair with uracil. This pairing occurs through hydrogen bonds; adenine forms two hydrogen bonds with uracil.

4. **Eliminate Incorrect Options**:
- Thymine is not present in RNA, so it cannot be the correct answer.
- Guanine pairs with cytosine (C), so this option is also incorrect.
- Cytosine does not pair with adenine, thus it is not the correct answer.

5. **Conclude the Correct Answer**:
- The only correct pairing for adenine in RNA is with uracil.

### Final Answer:
Adenine base always pairs with uracil in RNA.

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