Types of histone proteins present in nuclesome core are

Options

A. 4
B. 5
C. 8
D. 9

Answer

### Step-by-Step Solution:

1. **Understanding Nucleosome Structure**:
- A nucleosome is the fundamental unit of chromatin, consisting of a segment of DNA wrapped around a core of histone proteins.
- The core of the nucleosome is made up of an octamer of histone proteins.

2. **Identifying Histone Proteins**:
- The histone octamer consists of two copies each of four different types of histone proteins:
- H2A
- H2B
- H3
- H4

3. **Counting the Types of Histones**:
- Since there are two copies of each of the four types of histones, we can summarize:
- Total types of histone proteins = 4 (H2A, H2B, H3, H4).

4. **Evaluating the Options**:
- The question provides options, and we need to identify which option correctly states the number of histone types in the nucleosome core.
- The first option states "4", which is correct.

5. **Conclusion**:
- Therefore, the types of histone proteins present in the nucleosome core are four: H2A, H2B, H3, and H4.

### Final Answer:
The types of histone proteins present in the nucleosome core are 4.

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