Oogonium is

Options

A. haploid
B. diploid
C. triploid
D. euploid

Answer

### Step-by-Step Solution:

1. **Understanding Oogonium**:
- Oogonium is the initial stage in the process of oogenesis, which is the formation of female gametes (ova) in the ovaries.

2. **Oogenesis Process**:
- Oogenesis involves several stages:
- Oogonia undergo mitosis to form primary oocytes.
- Primary oocytes are diploid (2n) and are arrested in prophase I of meiosis.

3. **Meiosis in Oogenesis**:
- When the primary oocyte resumes meiosis, it undergoes the first meiotic division (meiosis I), resulting in a secondary oocyte and a polar body.
- The secondary oocyte is haploid (n) and can undergo the second meiotic division (meiosis II) upon fertilization.

4. **Ploidy Levels**:
- Oogonia are diploid (2n) because they contain two sets of chromosomes.
- Primary oocytes are also diploid (2n) before meiosis begins.
- Secondary oocytes and mature ova (ova) are haploid (n) after meiosis.

5. **Conclusion**:
- Since oogonia are the precursor cells that divide to form primary oocytes, they are classified as diploid.

### Final Answer:
Oogonium is a diploid structure (2n).