Which of the following represents uridylic acid ?

Options

A. Uracil + Ribose
B. Uridine + Phosphoric acid
C. Uracil + Phosphoric acid
D. Uridine + Ribose + Phosphoric acid

Answer

To solve the question "Which of the following represents uridylic acid?", we need to understand what uridylic acid is and its components.

### Step-by-Step Solution:

1. **Identify Uridylic Acid**:
- Uridylic acid is also known as uridine monophosphate (UMP). It is a nucleotide that plays a crucial role in RNA.

2. **Components of Uridylic Acid**:
- UMP is composed of three main components:
- A nitrogenous base: Uracil
- A sugar: Ribose
- A phosphate group: Phosphoric acid

3. **Analyze the Options**:
- **Option A**: Uricil plus ribose
- This does not include the phosphate group, so it is not uridylic acid.
- **Option B**: Uridine plus phosphoric acid
- This is close, but it does not include ribose as a separate entity.
- **Option C**: Uricil plus phosphoric acid
- This option uses "uricil" instead of "uridine," which is incorrect.
- **Option D**: Uridine plus ribose plus phosphoric acid
- This option includes all three components: uridine (the nucleoside), ribose (the sugar), and phosphoric acid (the phosphate group).

4. **Conclusion**:
- The only option that correctly represents uridylic acid (uridine monophosphate) with all its components is **Option D**: Uridine plus ribose plus phosphoric acid.

### Final Answer:
**Option D: Uridine plus ribose plus phosphoric acid.**

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