Nucleoside differ from a nucleotide .It lacks the :

Options

A. base
B. sugar
C. phosphate group
D. hydroxyl group

Answer

To answer the question "Nucleoside differs from a nucleotide. It lacks the:", we need to understand the structural components of both nucleosides and nucleotides.

### Step-by-Step Solution:

1. **Definition of Nucleoside**:
- A nucleoside is composed of two main components: a nitrogenous base (which can be adenine, guanine, cytosine, thymine, or uracil) and a sugar molecule (which is usually a pentose sugar like ribose or deoxyribose).
- Therefore, a nucleoside can be represented as:
\[ \text{Nucleoside} = \text{Nitrogenous Base} + \text{Sugar} \]

2. **Definition of Nucleotide**:
- A nucleotide, on the other hand, includes all the components of a nucleoside but with the addition of a phosphate group.
- Thus, a nucleotide can be represented as:
\[ \text{Nucleotide} = \text{Nitrogenous Base} + \text{Sugar} + \text{Phosphate Group} \]

3. **Comparison**:
- The key difference between a nucleoside and a nucleotide is the presence of the phosphate group.
- While both nucleosides and nucleotides contain a nitrogenous base and a sugar, the nucleotide has an additional phosphate group.

4. **Conclusion**:
- Therefore, the statement can be concluded as: A nucleoside lacks the phosphate group, which is present in nucleotides.

### Final Answer:
Nucleoside differs from a nucleotide because it lacks the **phosphate group**.

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