Exchange of chromosome segments between maternal and paternal chromatids during meiosis is called.
Or
In meiosis the daughter cells are not similar to that of parent because of

Options

A. Dyad formation
B. Bivalent formation
C. Crossing over
D. Synapsis

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the exchange of chromosome segments between maternal and paternal chromatids during meiosis, and why the daughter cells are not similar to the parent cells.

2. **Key Terms**:
- **Chromatids**: These are the two identical halves of a replicated chromosome.
- **Maternal and Paternal Chromatids**: Maternal chromatids come from the mother, and paternal chromatids come from the father.
- **Meiosis**: A type of cell division that reduces the chromosome number by half, resulting in four daughter cells, each genetically different from the parent cell.

3. **Identifying the Process**: The exchange of chromosome segments between maternal and paternal chromatids during meiosis is known as **crossing over**. This occurs during the prophase I stage of meiosis.

4. **Meiosis Overview**:
- Meiosis consists of two main stages: Meiosis I and Meiosis II.
- Meiosis I is a reductional division where homologous chromosomes are separated, reducing the chromosome number by half.

5. **Crossing Over**:
- Crossing over occurs during the **pachytene stage** of prophase I.
- During this process, non-sister chromatids of homologous chromosomes exchange segments of genetic material.

6. **Result of Crossing Over**:
- This exchange leads to genetic variation in the daughter cells, making them genetically distinct from the parent cell.
- As a result, the daughter cells produced at the end of meiosis are not identical to the parent cell due to this genetic recombination.

7. **Conclusion**:
- The answer to the question is that the exchange of chromosome segments is called **crossing over**.
- The reason the daughter cells are not similar to the parent cells is due to this process of crossing over.

### Final Answer:
The exchange of chromosome segments between maternal and paternal chromatids during meiosis is called **crossing over**. The daughter cells are not similar to the parent cells because of this crossing over.

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