Which stage of meiotic division involves the separation of homologous chromosomes, resulting in the reduction of the chromosome number ?

Options

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

Answer

To determine which stage of meiotic division involves the separation of homologous chromosomes, resulting in the reduction of the chromosome number, we can analyze the stages of meiosis.

### Step-by-Step Solution:

1. **Understanding Meiosis**: Meiosis is a type of cell division that reduces the chromosome number by half, resulting in four haploid cells from one diploid cell. It consists of two main stages: Meiosis I and Meiosis II.

2. **Identifying Meiosis I**: In Meiosis I, homologous chromosomes are separated. This is crucial for reducing the chromosome number from diploid (2n) to haploid (n).

3. **Prophase I**: During Prophase I, homologous chromosomes undergo synapsis and form tetrads. This stage involves the exchange of genetic material through crossing over but does not involve the separation of homologous chromosomes.

4. **Metaphase I**: In Metaphase I, homologous chromosomes line up at the metaphase plate. They are still paired and not yet separated.

5. **Anaphase I**: This is the key stage where the homologous chromosomes are pulled apart to opposite poles of the cell. This separation results in the reduction of the chromosome number, as each pole receives one chromosome from each homologous pair.

6. **Telophase I**: In Telophase I, the cell divides into two daughter cells, but the reduction of chromosome number has already occurred during Anaphase I.

7. **Conclusion**: The stage of meiotic division that involves the separation of homologous chromosomes, leading to the reduction of the chromosome number, is **Anaphase I**.

### Final Answer:
**Anaphase I**

---