The homologous chromosomes separate while sister chromatids remain associated at their centromeres in

Options

A. Anaphase-I
B. Telophase-I
C. Metaphase-I
D. Prophase-I

Answer

To solve the question "The homologous chromosomes separate while sister chromatids remain associated at their centromeres in," we need to analyze the stages of meiosis and identify where this specific event occurs.

### Step-by-Step Solution:

1. **Understanding Chromosome Structure**:
- Homologous chromosomes are pairs of chromosomes (one from each parent) that are similar in shape, size, and genetic content.
- Sister chromatids are identical copies of a single chromosome, connected at a region called the centromere.

2. **Identifying Meiosis Stages**:
- Meiosis consists of two rounds of division: Meiosis I and Meiosis II.
- In Meiosis I, homologous chromosomes are separated, while in Meiosis II, sister chromatids are separated.

3. **Analyzing Anaphase I**:
- During Anaphase I of meiosis, homologous chromosomes are pulled apart to opposite poles of the cell.
- Importantly, sister chromatids remain attached at their centromeres during this phase.

4. **Evaluating Other Phases**:
- **Telophase I**: This is the phase after Anaphase I where the chromosomes reach the poles and the cell begins to divide. The separation of homologous chromosomes has already occurred.
- **Metaphase I**: In this phase, homologous chromosomes are aligned at the equatorial plane, not separated.
- **Prophase I**: This is the initial phase where homologous chromosomes pair up and undergo crossing over, but separation has not yet occurred.

5. **Conclusion**:
- The correct answer is **Anaphase I**, as this is the stage where homologous chromosomes separate while sister chromatids remain associated at their centromeres.

### Final Answer:
The homologous chromosomes separate while sister chromatids remain associated at their centromeres in **Anaphase I**.

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