Nucleosome contains

Options

A. `H_(2)A, H_(2)B, H_(3),H_(4)`
B. `H_(3),H_(4)`
C. `H_(2)A,H_(2)B,H_(3)`
D. `H_(1),H_(2)A,H_(2)B,H_(3)`

Answer

**Step-by-Step Solution:**

1. **Understanding Nucleosome Structure**: A nucleosome is the fundamental unit of DNA packaging in eukaryotic cells. It consists of a segment of DNA wrapped around a core of histone proteins.

2. **Identifying Histone Proteins**: The nucleosome is made up of eight histone proteins, which are organized into an octamer. The specific histone proteins that make up this octamer are H2A, H2B, H3, and H4.

3. **Composition of the Octamer**: In a nucleosome, there are two copies of each of the four histone types, leading to a total of eight histones (2 H2A, 2 H2B, 2 H3, and 2 H4).

4. **Evaluating the Options**:
- Option A: H2A, H2B, H3, and H4 - This option includes all the histones present in a nucleosome, making it correct.
- Option B: H3 and H4 - This option is incorrect as it excludes H2A and H2B.
- Option C: H2A, H2B, and H3 - This option is incorrect as it excludes H4.
- Option D: H1, H2A, H2B, or H3 - This option is incorrect as it includes H1, which is not part of the nucleosome core.

5. **Conclusion**: The correct answer is Option A, which includes all the histone proteins present in a nucleosome.

**Final Answer**: A. H2A, H2B, H3, and H4.

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