1st polar body is formed at which stage of oogenesis?

Options

A. 1 st meisosis
B. 2nd mitosis
C. 1 st mitosis
D. Differentiation

Answer

To determine at which stage of oogenesis the first polar body is formed, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Oogenesis**: Oogenesis is the process of egg (ovum) formation in females. It involves several stages of cell division and maturation.

2. **Identify the Initial Cell Type**: The process begins with oogonia, which are the precursor cells that undergo mitotic division to form primary oocytes.

3. **Formation of Primary Oocytes**: Oogonia divide mitotically to produce primary oocytes. Each primary oocyte is surrounded by granulosa cells, forming a structure known as a primordial follicle.

4. **Meiosis Initiation**: Primary oocytes enter the first meiotic division (meiosis I) but are arrested in prophase I until puberty.

5. **Completion of Meiosis I**: When the primary oocyte resumes meiosis, it completes the first meiotic division. This division is asymmetrical, resulting in two cells: a larger secondary oocyte and a smaller polar body.

6. **Polar Body Formation**: The smaller cell produced during this division is known as the first polar body. It typically does not participate in further development and is eventually discarded.

7. **Conclusion**: Therefore, the first polar body is formed during the first meiotic division (meiosis I) of oogenesis.

### Final Answer:
The first polar body is formed at the stage of **first meiosis (meiosis I)**.

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