The number of chromosomes in a mature gamete gets halved during;

Options

A. Meiosis II
B. Formationof first polar body
C. Formation of second polar body
D. Division of secondary oocyte and secondary spermatocyte

Answer

To answer the question regarding when the number of chromosomes in a mature gamete gets halved, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Gametes**: Gametes are the reproductive cells in organisms, specifically sperm in males and eggs (ova) in females. Each gamete is haploid, meaning it contains half the number of chromosomes compared to the diploid somatic cells.

2. **Meiosis Overview**: The process of gamete formation occurs through meiosis, which consists of two main stages: Meiosis I and Meiosis II. Meiosis is a type of cell division that reduces the chromosome number by half.

3. **Meiosis I**: During Meiosis I, homologous chromosomes are separated. This is the reductional division where the chromosome number is halved. After this stage, each gamete will have half the number of chromosomes.

4. **Meiosis II**: Meiosis II is similar to mitosis, where sister chromatids are separated. However, this does not further reduce the chromosome number; it only separates the chromatids.

5. **Polar Body Formation**: In females, during the first meiotic division, a polar body is formed along with the primary oocyte. The primary oocyte undergoes meiosis to produce a secondary oocyte and a polar body, which typically does not participate in fertilization.

6. **Conclusion**: The halving of the chromosome number in a mature gamete occurs during Meiosis I, specifically when the first polar body is formed. Therefore, the correct answer to the question is the formation of the first polar body.

### Final Answer:
The number of chromosomes in a mature gamete gets halved during the formation of the first polar body (which occurs during Meiosis I).

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