Number of histone proteins present in one nuclesome core is

Options

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

Answer

To determine the number of histone proteins present in one nucleosome core, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of a Nucleosome**:
- A nucleosome is the fundamental unit of chromatin and consists of DNA wrapped around a core of histone proteins.

2. **Identify the Core Histones**:
- The core of the nucleosome is made up of four types of histone proteins: H2A, H2B, H3, and H4.
- Each of these histones is present in pairs, meaning there are two of each type.

3. **Calculate the Total Number of Core Histones**:
- Since there are four types of histones and each type has two copies, the calculation is as follows:
- H2A (2) + H2B (2) + H3 (2) + H4 (2) = 2 + 2 + 2 + 2 = 8 histone proteins.

4. **Consider Linker Histones**:
- While there are also linker histones (such as H1), they are not part of the nucleosome core. The question specifically asks for the histones present in the nucleosome core.

5. **Select the Correct Answer**:
- Based on the information above, the total number of histone proteins present in one nucleosome core is 8.

### Final Answer:
- The number of histone proteins present in one nucleosome core is **8**.

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