Linker DNA binds

Options

A. H2A and H4
B. H4 and H4
C. Two adjacent nucleosomes
D. Nucleosome and H1

Answer

To answer the question "Linker DNA binds to which of the following?", we will analyze the options step by step.

### Step-by-Step Solution:

1. **Understanding Linker DNA**: Linker DNA is the stretch of DNA that connects two nucleosomes. It is not wrapped around histones like the DNA in nucleosomes.

2. **Identifying Histones**: Histones are proteins that help package DNA into structural units called nucleosomes. The core histones are H2A, H2B, H3, and H4, which form the octamer around which DNA is wrapped.

3. **Analyzing the Options**:
- **Option 1: H2A and H4**: This option is incorrect because H2A and H4 are core histones that make up the nucleosome, not the linker DNA.
- **Option 2: H4 and H4**: This option is also incorrect as it repeats the same histone and does not refer to linker DNA.
- **Option 3: Two adjacent nucleosomes**: This option is correct. Linker DNA binds to the linker histone (H1), which connects two adjacent nucleosomes.
- **Option 4: Nucleosome and H1**: This option is incorrect because while H1 is a linker histone, it does not directly refer to the binding of linker DNA.

4. **Conclusion**: The correct answer is that linker DNA binds to the linker histone H1, which links two adjacent nucleosomes.

### Final Answer:
Linker DNA binds to **linker histone H1**, which connects two adjacent nucleosomes.

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