Nucleosome contains `:`

Options

A. Only histone protein
B. Both DNA and histone protein
C. Only DNA
D. Both DNA and RNA

Answer

To answer the question "Nucleosome contains:", we can break down the information into clear steps:

### Step-by-Step Solution:

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

2. **Components of a Nucleosome**:
- The core of the nucleosome is made up of a **histone octamer**.
- A histone octamer consists of **8 histone proteins**. These proteins are rich in the amino acids **lysine** and **arginine**.

3. **DNA Length**:
- Approximately **200 base pairs** of DNA are wrapped around each histone octamer.
- This wrapping of DNA around the histone proteins helps in compacting the DNA within the nucleus.

4. **Formation of Chromatin**:
- Nucleosomes are the repeating units that make up chromatin, which has a characteristic "beads on a string" appearance under an electron microscope.
- The "beads" represent the nucleosomes, while the "string" represents the linker DNA that connects them.

5. **Conclusion**:
- Therefore, a nucleosome contains both **DNA** and **histone proteins**.

### Final Answer:
A nucleosome contains **DNA and histone proteins**.