At which stage of meiosis does the genetic constitution of gametes is finally decided?

Options

A. (a) Metaphase I
B. (b) Anaphase II
C. (c) Metaphase II
D. (d) Anaphase I

Explanation

To determine at which stage of meiosis the genetic constitution of gametes is finally decided, we need to analyze the stages of meiosis closely.

### Step-by-Step Solution:

1. **Understanding Meiosis**: Meiosis consists of two rounds of division: Meiosis I and Meiosis II. Each round has specific stages: prophase, metaphase, anaphase, and telophase.

2. **Meiosis I**: In Meiosis I, the cell undergoes a series of events that lead to the separation of homologous chromosomes. This is where genetic variation can occur due to crossing over.

3. **Crossing Over**: During prophase I, homologous chromosomes pair up and exchange genetic material through a process called crossing over. This is crucial for genetic diversity.

4. **Anaphase I**: At this stage, the homologous chromosomes are pulled apart to opposite poles of the cell. The genetic constitution of the gametes is determined here because the chromosomes that are separated will dictate the genetic makeup of the resulting gametes.

5. **Meiosis II**: After Meiosis I, the two daughter cells undergo Meiosis II, which separates the sister chromatids. However, by the end of Anaphase I, the genetic constitution has already been established, and no further genetic exchange occurs.

6. **Conclusion**: Therefore, the stage of meiosis at which the genetic constitution of gametes is finally decided is **Anaphase I of Meiosis I**.

### Final Answer:
The genetic constitution of gametes is finally decided at **Anaphase I of Meiosis I**.

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