Select the nucleoside
(I)Adenosine
(II) Uridylic acid (III)Uridine
(IV) Cytidylic acid

Options

A. I and II only
B. I and III only
C. III and IV only
D. II and III only

Answer

To determine which of the given options is a nucleoside, we need to understand the definition of a nucleoside and differentiate it from nucleotides.

### Step-by-Step Solution:

1. **Understanding Nucleosides and Nucleotides**:
- A **nucleoside** consists of a nitrogenous base attached to a sugar (ribose or deoxyribose) without any phosphate group.
- A **nucleotide** is a nucleoside that has one or more phosphate groups attached.

2. **Analyzing the Options**:
- **(I) Adenosine**: This is a nucleoside formed from the nitrogenous base adenine and ribose sugar.
- **(II) Uridylic acid**: This is a nucleotide, as it contains uracil (a nitrogenous base) attached to ribose sugar and has a phosphate group.
- **(III) Uridine**: This is a nucleoside formed from the nitrogenous base uracil and ribose sugar.
- **(IV) Cytidylic acid**: This is a nucleotide, as it contains cytosine (a nitrogenous base) attached to ribose sugar and has a phosphate group.

3. **Identifying the Nucleosides**:
- From the analysis, the nucleosides in the options are:
- Adenosine (I)
- Uridine (III)

4. **Final Answer**:
- The correct nucleosides from the options provided are **(I) Adenosine** and **(III) Uridine**.

### Conclusion:
The nucleosides in the given options are **Adenosine (I)** and **Uridine (III)**.

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