In oogenesis, all divisions are mitotic except during the formation of

Options

A. oogonia
B. primary oocytes
C. first polar body
D. second polar body

Answer

### Step-by-Step Solution:

1. **Understanding Oogenesis**: Oogenesis is the process of egg (ovum) formation in females. It involves several stages, starting from the formation of oogonia to the development of mature ova.

2. **Identifying the Types of Cell Division**: In oogenesis, there are two types of cell division:
- **Mitosis**: This is a type of cell division that results in two identical daughter cells. It occurs during the formation of oogonia and primary oocytes.
- **Meiosis**: This is a specialized type of cell division that reduces the chromosome number by half and results in the formation of gametes. It occurs during the formation of secondary oocytes and polar bodies.

3. **Formation of Oogonia**: Oogonia are the initial cells formed in the ovaries. They are produced through mitotic divisions. Therefore, the formation of oogonia involves mitosis.

4. **Formation of Primary Oocytes**: Primary oocytes are formed from oogonia through mitotic division. Thus, this stage also involves mitosis.

5. **Meiotic Division**: The primary oocyte undergoes meiosis to form a secondary oocyte and the first polar body. This is the key step where meiosis occurs.

6. **Polar Bodies Formation**: The first polar body is formed during the meiotic division of the primary oocyte. The second polar body is also formed during the second meiotic division of the secondary oocyte, but it is not the focus of the question.

7. **Conclusion**: Among the options provided, the only division that is not mitotic is during the formation of the **first polar body**, which is produced through meiosis.

### Final Answer:
In oogenesis, all divisions are mitotic except during the formation of the **first polar body**.

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