Which of the following not occur during condensation of chromosomes:-

Options

A. Unfolding of protein molecules
B. Coiling of DNA
C. Dehydration
D. Hydration

Answer

To solve the question "Which of the following does not occur during the condensation of chromosomes?", we will analyze the options provided and understand the process of chromosome condensation.

### Step-by-Step Solution:

1. **Understanding Chromosome Condensation**:
- Chromosome condensation is the process where chromatin (the material that makes up chromosomes) becomes more compact during cell division (mitosis and meiosis). This process is crucial for the proper segregation of chromosomes.

2. **Identifying Events During Condensation**:
- During condensation, the long, thin strands of chromatin undergo several changes:
- **Coiling of DNA**: The DNA coils tightly to form the compact structure of chromosomes.
- **Unfolding of Protein Molecules**: Proteins associated with DNA, such as histones, may undergo changes to help facilitate this coiling.
- **Dehydration**: Water is removed from the chromatin structure, which aids in the compaction process.

3. **Evaluating the Options**:
- Option 1: **Unfolding of the protein molecules** - This occurs during condensation.
- Option 2: **Coiling of DNA** - This also occurs during condensation.
- Option 3: **Dehydration** - This happens during condensation as water is removed.
- Option 4: **Hydration** - This does not occur during condensation, as the process involves dehydration.

4. **Conclusion**:
- The correct answer is **Option 4: Hydration**, as this event does not take place during the condensation of chromosomes.

### Final Answer:
**Option 4: Hydration**

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