In each of the following questions, a statement of Assertion is given followed by corresponding statement of Reason of the statement, mark the correct alternative as directed below.
Assertion : Histone proteins are synthesized during S-phase.
Reason: Histone proteins formed are associated with DNA, to form bead like nucleosomes.

Options

A. If both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
B. If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion
C. If Assertion is true, but Reason is false.
D. If both Assertion and Reason are false.

Answer

To analyze the given assertion and reason statements, we will break down the information step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Histone proteins are synthesized during S-phase."
- The S-phase (Synthesis phase) is part of the cell cycle where DNA replication occurs. During this phase, not only is DNA replicated, but also the proteins that are necessary for DNA packaging, such as histones, are synthesized.

2. **Understanding the Reason**:
- The reason states that "Histone proteins formed are associated with DNA, to form bead-like nucleosomes."
- Histone proteins are indeed positively charged proteins that bind to negatively charged DNA. This interaction leads to the formation of nucleosomes, which are structures that resemble beads on a string. Each nucleosome consists of a segment of DNA wrapped around a core of histone proteins.

3. **Evaluating the Relationship**:
- The assertion is true because histone proteins are synthesized during the S-phase.
- The reason is also true because histone proteins do associate with DNA to form nucleosomes.
- Furthermore, the reason correctly explains why histone proteins are important during the S-phase.

4. **Conclusion**:
- Both the assertion and the reason are true, and the reason correctly explains the assertion.

### Final Answer:
- Both Assertion and Reason are true, and the Reason is a correct explanation of the Assertion.

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